Dermatitis

We report the results of patch-testing with a low concentration (0.1%) of Dermatophagoides mix. Patch-testing to this preparation (the atopy patch test) has been advocated as a means of identifying patients with atopic dermatitis who would benefit from avoidance of Dermatophagoides (dust mite). In 2002, we reported a very high rate of reaction after an assessment of the results of adding the commercially available 20% Dermatophagoides mix to our standard series.1 Of 662 patients who had patch tests with the preparation, 55% had a reaction at 96 hours, a rate higher than with any of the other allergens in the standard series. This report was consistent with a report by Jamora and colleagues,, 2 who found that a high proportion—15 of 18 (83%) nonatopic healthy control subjects—had positive reactions to the 20% Dermatophagoides preparation. After patch-testing patients to different dilutions of the allergen, Jamora and colleagues reported that a 0.1% dilution of 20% Dermatophagoides pteronyssinus/farinae mix antigen (Chemotechnique Diagnostics, Malmö, Sweden) was useful for identifying mite-allergic persons with atopic dermatitis. We therefore substituted a 0.1% dilution (in petrolatum) for the 20% D. pteronyssinus/farinae mix antigen in our standard series during the 2 years from April 1, 2002, to March 31, 2004.

The standard allergen series used in patch testing contains metals that most commonly cause allergic contact dermatitis, but testing with additional metal allergens is warranted for select patients. To report our experience with patch testing of metals. We retrospectively analyzed outcomes of 1,112 patients suspected of having metal allergies. Patients were seen from January 1, 2000, through December 31, 2009. Patch testing was performed with 42 metal preparations (6 in the standard series, 36 in the metal series). Patch testing most commonly was performed for patients with oral disease (almost half the patients), hand dermatitis, generalized dermatitis, and dermatitis affecting the lips, legs, arms, trunk, or face. At least one positive reaction was reported for 633 patients (57%). Metals with the highest allergic patch-test reaction rates were nickel, gold, manganese, palladium, cobalt, Ticonium, mercury, beryllium, chromium, and silver. Metals causing no allergic patch-test reactions were titanium, Vitallium, and aluminum powder. Metals with extremely low rates of allergic patch-test reactions included zinc, ferric chloride, and tin. Reaction rates varied depending on metal salt, concentration, and timing of readings. Many metals not in the standard series were associated with allergic patch-test reactions. The many questions raised by these findings, concerning patch testing with individual metals, will be the subject of future studies.

Isocyanates with the general formula R-(N=C=O) are theoretically contact sensitizers. However, allergic contact dermatitis (ACD) from isocyanates is seldom reported. In previous reports, patients reacted to their isocyanate-based work materials but not to commercial patch-test preparations of isocyanates. Therefore, we suspected that the low frequency of reported ACD from isocyanates was partly due to inadequate commercial preparations. A past study also showed the concentrations of diphenylmethane-4,4'-diisocyanate (4,4'-MDI) in petrolatum preparations to be much lower than declared. In this study, 2,4-toluene diisocyanate (2,4-TDI), 1,6-hexamethylene diisocyanate (1,6-HDI), and isophorone diisocyanate (IPDI) were investigated in a similar fashion. In preparations from 12 dermatology departments and two suppliers of patch-test allergens, we determined the isocyanate content as the isocyanate-dibutylamine derivative, using liquid chromatography and mass spectrometry. The preparations were considered stable if the ratio between the stated and found concentrations was within the range of 0.8 to 1.2. Although 28 of 36 investigated preparations had ratios outside of the stable range, they were in its vicinity, which indicates that preparations of 2,4-TDI, 1,6-HDI, and IPDI are more stable than are preparations of 4,4'-MDI where previously reported results showed ratios far outside of stable range. As opposed to preparations of 4,4'-MDI, preparations of 2,4-TDI, 1,6-HDI, and IPDI can be considered to be stable.

The Thin-layer Rapid Use Epicutaneous (TRUE) Test has approval for adults. To evaluate the efficacy and safety of TRUE Test panels 1.1, 2.1, and 3.1 in children and adolescents suspected of having allergic contact dermatitis (ACD). An open-label prospective study was performed, analyzing 102 consecutive patients aged 6 to 18 years referred for suspected ACD, between December 2008 and October 2009. Patch tests were applied for 48 hours, and evaluations of skin reactions were conducted at days 3 and 7, with a follow-up visit 3 weeks after the initial applications. The mean age of all enrolled subjects was 11.6 years, and subjects included 52% females and 48% males. Positive reactions noted in more than 10% of the children were to nickel sulfate (29.7%), p-tert-butylphenol formaldehyde resin (16.8%), wool alcohols (15.8%), fragrance mix (12.9%), and cobalt dichloride (12.9%). Of the 101 subjects, 77 (76.2%) tested positive to one or more of the 28 allergens. No meaningful differences were observed in the frequency or severity of adverse events; reports of burning and stinging following patch removal; or the frequency, intensity, or symptoms of persistent reactions when evaluated by age, sex, or race. Patch testing is efficacious and safe in the pediatric population.

Irritation from surfactants contained in detergents is a frequent adverse reaction to cosmetics. Sensitization to surfactants is also possible. In the literature, comparative studies about irritant and sensitizing potential of different surfactants are heterogeneous and inconclusive about the best molecules to use. We compared the irritant and sensitizing potential of some surfactants that are usual components in marketed synthetic detergents (syndets) to obtain practical information regarding commonly used detergents. We patch-tested eight surfactants of the different types (anionic, cationic, amphoteric, and non-ionic) in 105 patients. Assessment of allergic reactions of tested surfactants was carried out in accordance with the recommendations of the International Contact Dermatitis Research Group; assessment of irritant power followed the amended Draize classification. None of the eight surfactants in our series gave positive allergic reactions. Only cocamidopropyl betaine from the Italian standard (Società Italiana di Dermatologia Allergologica, Professionale e Ambientale [SIDAPA]) series gave five positive reactions among 105 patients. None of the eight studied surfactants induced skin irritation. The most tolerated are two new mild anionics (sodium cocoyl glutamate and sodium lauroyl oat amino acids) and an amphoteric agent (disodium cocoamphodiacetate). From this study, we deduce that cosmetic companies' efforts to search for and market new products with very mild surfactants have been generally successful.

The potentially functionally relevant IL10 -1082A>G (rs1800896) promoter region single-nucleotide polymorphism has been implicated in the pathogenesis of atopic dermatitis (AD). Although this relationship has been studied extensively, these association studies were limited by small sample size. To increase statistical power and obtain a more precise estimate of the association, literature evidence on IL10 -1082A>G and AD was assessed by conducting a systematic review and meta-analysis. This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. PubMed (MEDLINE), EMBASE, Scopus, and HuGE Literature Finder literature databases were systematically searched for relevant studies. Summary odds ratios and corresponding 95% confidence intervals were estimated using the fixed-effect inverse variance analysis method for allelic (G vs A) and genotypic comparisons. Meta-analysis of 7 studies (n = 849 cases and 1195 controls) found a nonsignificant association between the IL10 -1082A>G polymorphism and AD (allelic odds ratio, 1.02; 95% confidence interval, 0.88-1.19; P = 0.77). This study was unable to find a direct association between IL10 -1082A>G and AD. Further studies are needed to reveal the contributions of haplotype and gene-gene and gene-environment interaction effects involving this single-nucleotide polymorphism to AD.

Preservatives are indispensable agents used to prevent bacterial and fungal contamination of cosmetics, personal care products, domestic preparations, and industrial products. We evaluated patch-test data at the National Skin Centre, Singapore, from 2006 to 2011 to identify the trends in preservative contact allergies. All patients with suspected contact dermatitis were patch tested to 4 preservatives within the modified European standard series. Patients were also tested with 7 preservatives from our special series if clinically indicated. Three thousand one hundred seventy-seven patients were tested to preservatives in the standard series. Sensitization frequencies were all greater than 1%: parabens (2.58%), methylchloroisothiazolinone/methylisothiazolinone (1.75%), quaternium 15 (1.43%), and methyldibromoglutaronitrile (1.2%). There was no change in trends in sensitization frequencies from 2006 to 2011, with no increase in sensitization frequency to methylchloroisothiazolinone/methylisothiazolinone. The sensitization frequencies for methyldibromoglutaronitrile/phenoxyethanol and diazolidinylurea were 2.03% and 1.37%, respectively, and remained less than 1% for bronopol, imidazolidinyl urea, and 2-phenoxyethanol. A rate of 0% was seen for 1,3-dimethylol-5,5-dimethyl hydantoin and formaldehyde; 9.4% of positive patch-test results became positive only at day 7. Preservatives are common causes of allergic contact dermatitis. This should be considered when introducing new preservatives into the market. Day 7 readings are important to detect late reactions.

An update of the information about the prevailing trend of cutaneous adverse drug reactions (CADRs) is important for clinicians. The objective of the study was to survey the prevalence of CADRs in Southwest China over the past 11 years. The clinical and laboratory data of all inpatients admitted with a diagnosis of CADRs to the dermatology ward of Southwest Hospital during the past 11 years were retrospectively investigated. In the 547 recruited patients, the most common clinical pattern was maculopapular eruptions (n = 277), followed by fixed drug eruptions (n = 84) and acute urticaria (n = 44). In 206 cases with single medication intake, the 3 most common culprit drugs were acetaminophen (n = 44), penicillins (n = 44), and cephalosporins (n = 30). The frequency of urticaria in the elderly (≥60 years old) (n = 117) was significantly lower than that in younger patients (<60 years old) (n = 430) (P = 0.046), whereas erythema multiforme was much more common in the elderly (P = 0.038). As compared with younger patients, allopurinol was the most common culprit drug in the elderly. In contrast to previous studies, our study showed that the prevalence profiles of CADRs in the elderly are quite different from those in younger population. Acetaminophen was the most common culprit drug for total CADRs, which should be alerted as an important public health problem.

In women with vulval complaints, irritant contact dermatitis is more common than allergic contact dermatitis, but secondary sensitization has to be taken into consideration since these patients often use several topical medications. The aims of this retrospective study were to establish the prevalence of allergic contact dermatitis in patients with vulval complaints and to verify how many patients with allergic contact dermatitis suffered from a previous pathology. We reviewed patch- and prick-test results from 92 women. The women had all been administered the European Standard series, and most had also been tested for other allergens such as the ingredients of topical pharmaceutical products and cosmetics. Thirty-five patients (38%) presented with one or more positive allergic reactions. For 15 of the patients, these reactions were considered to be relevant to their clinical condition and were most often due to contact dermatitis from topical pharmaceutical products. Three patients presented with positive and relevant contact urticaria syndrome from latex, and two patients presented with protein contact dermatitis from human seminal plasma. Patients with vulval dermatitis are at risk of developing contact sensitivities, particularly to topical pharmaceutical products; therefore, attention should be paid to this problem when such products are prescribed.

The impact of skin disease on heath-related quality of life (QoL) is often underrecognized, and there is little research about health-related QoL in patch-tested populations. A pilot study to assess baseline QoL in dermatitis patients referred to a specialized center for patch testing. A convenience sample of patients presenting for patch testing (n = 107) completed a survey, Skindex-16+5, which measures QoL in four domains: symptoms, emotions, functioning, and occupational. Responses were indexed from 0 (never bothered) to 100 (always bothered). Emotions (mean, 67; SD +/- 27) and symptoms (mean, 60; SD +/- 27) demonstrated the lowest QoL. Patients with hand involvement had a worse QoL in all areas, including the occupational domain, compared to patients without hand involvement. Limitations of the study included the referral clinic population and convenience sample. Survey questions added to Skindex-16 regarding the occupational domain have not been validated. Patients referred for patch testing endorse a highly negative impact of the disease on their emotional QoL and are also greatly bothered by symptoms. Patch-tested patients with hand dermatitis had a significantly lower QoL across all areas as compared to tested patients without hand involvement. Facial involvement, duration of skin problem, atopic history, occupation relationship, or positive patch-test results were not correlated with QoL.

Photopatch testing is important for diagnosing photoallergic contact dermatitis. Although results of photopatch testing have been presented from many European centers, there have been few reports of the results of photopatch testing in the United States. To review the Mayo Clinic's recent experience with photopatch testing, identify common photoallergens, and compare our current and previous findings. We retrospectively reviewed records of patients who underwent photopatch testing at the Mayo Clinic between January 1, 2000, and December 31, 2005 (N = 182). Fifty-four patients (29.7%) had photoallergic contact reactions, and 29 (15.9%) had allergic contact reactions. The most common photoallergens were medications, sunscreen agents, fragrances, and antiseptics. Photopatch testing is the technique useful in identifying photoallergens. The series of allergens used must be constantly updated to reflect newly identified and outdated photoallergens. We present a 6-year experience with photopatch testing. Medications, sunscreen agents, fragrances, and antiseptics were the most frequently identified photoallergens.

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. Recently, it was demonstrated that a large proportion of individuals with AD have an epidermal expression deficiency of filaggrin (FLG). This unique finding may have great implications for our understanding of nickel sensitization because nickel is chelated in the epidermis and perhaps to FLG. This review aims to briefly present the current knowledge about nickel sensitization in relation to FLG deficiency and speculate on its possible implications. The new knowledge concerning loss-of-function mutations in the FLG gene (the lack of specific nickel-chelating power in the stratum corneum and a generally defective skin barrier) suggests that an additive effect from irritants and nickel may aggravate hand eczema in individuals with loss-of-function mutations in the FLG gene. This hypothesis calls for a reevaluation of the potential risk of nickel sensitization through the establishment of cohorts with and without such mutations.

Vitamin E, of which the most biologically active form is alpha-tocopherol, has become widely known for its antioxidant effects. It has been ingested or applied topically for purported anti-aging effects and for cosmetic enhancement. To determine whether the incidence of allergic contact dermatitis from vitamin E has increased in recent years. With the approval of the Mayo Clinic institutional review board, we retrospectively analyzed patch-test data from patients tested from June 1987 through December 2007. A total of 2,950 patients were patch-tested during this period, and 18 patients (0.61%) had positive reactions to alpha-tocopherol; 6 (0.53%) of 1,136 patients tested from June 1987 through December 1997 had positive results, and 12 (0.66%) of 1,814 patients tested from January 1998 through December 2007 had positive results (p = .69). Vitamin E appears to be a relatively rare contact allergen in our experience.

The Depleted Uranium Follow-Up Program is a clinical surveillance program run by the Baltimore Veterans Affairs Medical Center since 1993 for veterans of the Gulf and Iraqi wars who were exposed to depleted uranium (DU) as a result of "friendly-fire" incidents. In 2009, 40 veterans from this cohort were screened for skin reactivity to metals by patch-testing with extended metal series and uranyl acetate (0.25%, 2.5%, and 25%). A control arm comprised 46 patients without any known occupational exposures to DU who were seen at the University of Maryland Dermatology Clinic for evaluation of allergic contact dermatitis. Excluding irritant reactions, no patch-test reactions to uranyl acetate were observed in the participants. Irritant reactions to DU were more common in the clinic cohort, likely reflective of the demographic differences between the two arms of the study. Biologic monitoring of urine uranium concentrations in the DU program participants with 24-hour urine samples showed evidence of percutaneous uranium absorption from the skin patches. We conclude that dermatitis observed in a subset of the veterans was unrelated to their military DU exposure. Our data suggest that future studies of skin testing with uranyl acetate should utilize 0.25%, the least irritating concentration.

The prevalence of lanolin sensitivity in referred patients is less than 4%. To (1) describe patients with positive patch-test reactions to lanolin, (2) determine clinical and occupational relevance associated with reactions to lanolin and common sources, and (3) examine the frequency of co-reacting allergens. A retrospective analysis of 26,479 patients patch-tested by the North American Contact Dermatitis Group (NACDG), 1994 to 2006. Overall, 2.5% of patients (643 of 25,811) tested to lanolin alcohol 30% in petrolatum had positive reactions. Prevalence decreased from 3.7% in 1996 to 1998 to 1.8% in 2005 to 2006 (p <.0001); 83.4% of all positive reactions were currently relevant, but only 2.5% were occupationally relevant. Lanolin-positive patients were 1.2 times more likely to be male and 1.4 times more likely to have a history of atopic dermatitis when compared to allergic, but lanolin-negative, patients (p < .0002 and p < .0001, respectively). Cosmetics were the most common source. Lanolin-positive patients were significantly more likely to be co-sensitized to another NACDG standard screening allergen (p <.0001). The prevalence of allergic patch-test reactions to lanolin in North America patch-test populations is decreasing. Current relevance of reactions was high, but occupational relevance was low. Concomitant reactions were more common in lanolin-positive patients.

Background: Contact dermatoses are common in food service workers (FSWs). Objectives: This study aims to (1) determine the prevalence of occupationally related contact dermatitis among FSWs patch tested by the North American Contact Dermatitis Group (NACDG) and (2) characterize responsible allergens and irritants as well as sources. Methods: Cross-sectional analysis of patients patch tested by the NACDG, 1994 to 2010, was conducted. Results: Of 35,872 patients patch tested, 1237 (3.4%) were FSWs. Occupationally related skin disease was significantly more common in FSWs when compared with employed non-FSWs. Food service workers were significantly more likely to have hand (P < 0.0001) and arm (P < 0.0006) involvement. The rates for irritant and allergic contact dermatitis in FSWs were 30.6% and 54.7%, respectively. Although the final diagnosis of irritant contact dermatitis was statistically higher in FSWs as compared with non-FSWs, allergic contact dermatitis was lower in FSWs as compared with non-FSWs. The most frequent currently relevant and occupationally related allergens were thiuram mix (32.5%) and carba mix (28.9%). Gloves were the most common source of responsible allergens. The NACDG standard tray missed at least 1 occupationally related allergen in 38 patients (4.3%). Conclusions: Among FSWs patch tested by the NACDG between 1994 and 2010, the most common allergens were thiuram mix and carba mix. Gloves were the most common source of responsible allergens.

In the last 20 years, the hairdressing profession has undergone important modifications, mainly because of a change in the substances and techniques used and improved occupational education. To evaluate the modifications in the hairdressing profession and its actual risk of occupational allergic contact dermatitis (OACD). We studied all 300 hairdressers seen in our department from 1994 to 2003 and compared the results with those of a previous study of 379 hairdressers who attended our department from 1980 to 1993. All were patch-tested with the European Standard series and specific hairdressing products. As previously, most of the workers were women (93%), with a mean age (23.7 years) slightly higher than that of the workers in our previous study. We found a significant increase in the frequency of positive patch-test responses (78.3% vs 58.8%) and OACD (58% vs 48.8%) with respect to our previous study. We also observed a significant increase in sensitization to most allergens, including p-phenylenediamine base (54% vs 45.9%), 4-aminobenzene (40.7% vs 31.9%), ammonium thioglycolate (2.7% to 12.3%), ammonium persulfate (7.9% to 14.3%), p-toluenediamine sulfate (6.8% to 15.3%), p-aminodiphenylamine (2.9% to 7.7%), o-nitro-4-phenylenediamine (2.1% to 7.3%), and aminophenols (0% to 9%), whereas a decrease was found in sensitization to Disperse Orange (17% vs 32.7%) and thioglycolic acid (15.3% to 3%). The high frequency and increase of sensitizations among hairdressers require urgent measures to improve protective measures and their application.

Mercaptobenzothiazole (MBT) and mercapto compounds are primarily used in rubber products. This study aimed to examine concomitant-positive rates of MBT (1% pet) and the 4-part mercapto mix (MM) (1% pet). This is a retrospective cross-sectional data from the North American Contact Dermatitis Group. A total of 30,880 patients were patch tested to MM and MBT. There were 333 positive reactions to MM and 427 positive reactions to MBT. Ninety-eight patients were positive to MM alone, 192 to MBT alone, and 235 reacted to both. Forty-five percent (192/427) of MBT reactions would have been missed by only testing to MM, and 29% (98/333) of MM reactions would have been missed by testing to MBT alone. Most of these "missed" reactions, however, were doubtful (+/-) or mild (+) (MBT, 65%; MM, 78%), whereas most reactions in patients who reacted to both were moderate (++) and/or strong (+++) (52.3%). Gloves were the most common source. Mercaptobenzothiazole is the preferential screening allergen for mercapto compounds because of the following: (1) greater proportion of missed reactions with MM; (2) greater proportion of doubtful/mild reactions in the missed group for MM; and (3) in the group positive to both, the low rate (2%) of moderate/strong reactions to MM and doubtful/mild reactions to MBT as compared with the converse (21%). Mercapto mix may be useful in an auxiliary rubber series.

Allergic contact dermatitis from thioureas is uncommon but may result from exposure to rubber, especially neoprene. To (1) describe the population with positive patch-test reactions to mixed dialkyl thioureas (MDTU) (ie, diethylthiourea and dibutylthiourea); (2) determine clinical and occupational relevance associated with reactions to MDTU and identify the most commonly related sources and occupations; and (3) examine the frequency of co-reacting allergens in MDTU-positive patients. A retrospective analysis of cross-sectional data of 22,025 patients patch-tested by the North American Contact Dermatitis Group between 1994 and 2004. Of 21,898 patients tested with MDTU, 225 (1.0%) had positive reactions; of these, 173 (76.9%) were currently relevant and 29 (17.1%) were occupationally relevant. Patients positive to MDTU were 2.6 times more likely to have foot involvement than patients with positive reactions to other allergens (p < .0001). Footwear was the most commonly identified source overall (20.0%) whereas gloves were the most common occupational source. Of the 173 patients with currently relevant MDTU reactions, 24.9% also reacted to another rubber allergen. Current clinical relevance of reactions to MDTU was high; occupational relevance was less frequent. Patch tests with common rubber allergens (carbamates, thiurams, and mercaptobenzothiazole) may fail to detect many cases of thiourea-induced rubber allergic contact dermatitis.

Background: European studies document that occupational contact dermatitis (CD) is common in hairdressers, but studies from North America are lacking. Objectives: The objectives of this study were to estimate the prevalence of occupational CD among North American hairdressers/cosmetologists (HD/CS) and to characterize responsible allergens and irritants as well as their sources. Methods: A cross-sectional analysis of patients patch tested by the North American Contact Dermatitis Group between 1994 and 2010 was conducted. Results: Of 35,842 patients, 432 (1.2%) were HD/CS. Significantly, most of the HD/CS were female (89.8%) and younger than 40 years (55.6%) as compared with non-hairdressers (P < 0.0001). The rates for allergic and irritant CD in HD/CS were 72.7% and 37.0%, respectively. The most common body site of involvement was the hand, and this was significantly more common than in non-HD/CS (P < 0.0001). The most frequent currently relevant and occupationally related allergens were glyceryl thioglycolate, p-phenylenediamine, nickel sulfate, 2-hydroxyethyl methacrylate, and quaternium-15. Hair dyes, permanent wave solutions, and other hair products were common sources of allergens. The North American Contact Dermatitis Group allergen series missed at least 1 occupationally-related allergen in 26.2% of patients. Conclusions: Contact dermatitis in North American HD/CS is common, and occupationally related allergens are those found in HD/CS products. Supplemental hairdressing/cosmetology antigen series are important in detecting all occupationally related allergens in this population.

Propolis, the bee glue, is increasingly used in biocosmetics and for the self-treatment of various diseases. Patients reacting to propolis were requested to participate in further testing with the breakdown constituents of the bee glue. Twenty-seven patients agreed to be tested with 18 constituents, including four caffeates (the typical allergens of propolis) derived from the sticky exudates of poplar buds. Seven patients did not react to the propolis constituents tested. In the remaining 20 patients, the four caffeates produced strong reactions. Phenylethyl caffeate, which produced positive reactions in 20 patients, was the leading contact allergen. Benzyl caffeate elicited strong responses in 18 patients, and 3-methyl-2-butenyl caffeate produced reactions in 17 patients. Geranyl caffeate produced positive reactions in 11 patients. The flavonoid tectochrysin gave positive results in 2 patients; ferulic acid, coumaric acid, and methyl cinnamate produced weak responses. In middle Europe, the caffeates are the responsible allergens in propolis allergy. Patients from other countries, where poplar trees do not grow, become allergic to other propolis constituents but not to the caffeates.

Propylene glycol (PG) may cause allergic or irritant contact dermatitis. It primarily functions as a vehicle, solvent, or emulsifier in cosmetics and topical medications. To characterize the prevalence of positive patch-test reactions to PG and the epidemiology of affected patients. Retrospective analysis of cross-sectional data compiled by the North American Contact Dermatitis Group (NACDG) from 1996 to 2006. Of 23,359 patients, 810 (3.5%) had allergic patch-test reactions to 30% PG; 12.8% of the reactions were of definite clinical relevance (positive reaction to a personal product containing PG), 88.3% were considered to be currently relevant (definite, probable, or possible relevance), and 4.2% of reactions were occupation related, most commonly to mechanical and motor vehicle occupations. Common sources of PG were personal care products (creams, lotions, and cosmetics, 53.8%), topical corticosteroids (18.3%), and other topical medicaments (10.1%). In patients positive only to PG (n = 135), the face was most commonly affected (25.9%), followed by a scattered or generalized pattern (23.7%). The most common concomitant reactions included reactions to Myroxilon pereirae, fragrance mix, formaldehyde, bacitracin, methyldibromoglutaronitrile/phenoxyethanol, carba mix, and tixocortol pivalate. In this select population of patients referred for patch testing, allergic reactions to PG were often currently clinically relevant but were rarely related to occupation. The most common sources were personal care products and topical corticosteroids.

Allergic contact sensitization may occur at any age, showing specific rates of sensitization and allergen frequency related to periods of life. To describe sensitization rates of specific allergens with respect to age distribution in adults in a cross-sectional study. Data of 713 patients referred for patch testing at the Massachusetts General Hospital Contact Dermatitis Clinic were analyzed. Testing was conducted with baseline (29 allergens) and customized series between January 1996 and December 2006. Although trends were noted, there was no statistically significant difference with respect to rate of sensitization or number of positive allergens in the various age groups. Fragrance mix and nickel sulfate were the most common allergens through all age groups. In older age groups, a statistically significant higher sensitization rate was shown for fragrance mix (p = .005) and balsam of Peru (p < .005) whereas the rate for nickel was lower (p = .002). For specific allergens such as nickel and fragrances, significant variations occur in different stages of life. Even with these variations, we found that the overall rates of positive patch-test reactions were similar in the three age groups evaluated.

Allergic contact dermatitis in children is a significant clinical problem. Patch testing is a diagnostic tool for the evaluation of patients with suspected allergic contact dermatitis. To determine the frequency and relevance of positive patch-test results in children and to identify the most common allergens in children at our clinic. Retrospective chart review of 100 children and adolescents, aged 4 to 18 years, who were patch-tested at the Ottawa Hospital patch-testing clinic between 1996 and 2006. The children were patch-tested with the North American Contact Dermatitis Group (NACDG) standard series, supplementary series if indicated, and their own products if available. Seventy percent of children had at least one positive patch-test reaction; 55.8% of positive patch-test reactions were relevant. The ratio of females to males was 62:38. The most common allergens were nickel sulfate (26%), cobalt (14%), fragrance mix (7%), neomycin (7%), colophony (6%), formaldehyde (4%), lanolin (4%), quaternium-15 (4%), and para-phenylenediamine (4%). Nickel co-reacted with cobalt (68%) and palladium (100%). Of children tested, 41% had a history of atopic dermatitis. The frequency of positive and relevant allergens in children is similar to that in adults as compared with data from the NACDG 2001-2002 study period. Differences between the top 10 allergens in children and adults were seen. Nickel and cobalt were more common allergens in children, and colophony, lanolin, and para-phenylenediamine ranked in the top 10 allergens among children.

Contact dermatoses are common in health care workers (HCWs). To (1) estimate the prevalence of occupation-relevant allergic contact dermatitis (ACD) among health care workers patch-tested from 1998 to 2004 by the North American Contact Dermatitis Group (NACDG), (2) characterize responsible allergens among health care workers overall as well as in specific health care occupational subgroups, and (3) compare these results to those of nonhealth care workers. Between 1998 and 2004, 15,896 patients were patch-tested by the NACDG. Occupation-related allergic patch-test results were analyzed among HCWs, subgroups of HCWs, and non-HCWs. 1,255 patients (7.9%) were HCWs. Female gender (HCWs, 86.2%; non-HCWs, 63.6%) and hand involvement (HCWs, 54.7%; non-HCWs, 27.8%) were more common in HCWs (p < .05); 18.2% of HCWs and 6.6% of non-HCWs had occupation-related allergens of current clinical relevance. Thiuram mix (HCWs, 8.87% non-HCWs, 0.90%) and carba mix (HCWs, 5.43%; non-HCWs, 0.87%) were the most common occupation-related currently relevant antigens in HCWs and were more common in HCWs than in non-HCWs (p < .05). Among HCWs patch-tested by the NACDG between 1998 and 2004, the most common allergens were thiuram mix and carba mix, followed by glutaraldehyde, cocamide diethanolamine, and chloroxylenol. Gloves, sterilizing solutions, and soaps were common sources of responsible allergens.

Carba mix (CM) contains 3 chemicals used as accelerators in manufacturing of rubber products and agricultural chemicals. Iodopropynyl butylcarbamate (IPBC) is a preservative used in industrial and personal care products. Potential cross-reactivity between these allergens is unclear. This study aimed to determine concomitant reaction rates between CM (3% petrolatum [pet]) and IPBC (0.1% pet and/or 0.5% pet). A retrospective cross-sectional analysis of data from the North American Contact Dermatitis Group from 1998 to 2008 was conducted. Frequencies of positive reactions, strength of reactions, and concomitant reaction rates were calculated. A total of 25,435 patients were tested. There were 1131 allergic reactions to CM and 346 positive reactions to IPBC (either 0.1% pet and/or 0.5% pet). Fifty-two patients reacted to both allergens. Most reactions (>69%) were doubtful/weakly positive, and of those who reacted to both, most (58%) had doubtful and/or weakly positive reactions. There was a statistically significant association of concomitant reactions between CM and IPBC; formaldehyde positivity was used as control and showed statistically significant concomitant reactions. Overall, concomitant reactions to CM and IPBC were low, and rates varied by strength of reaction. True cross-reactivity is unlikely; statistical association is likely due to frequent low-grade reactions to irritant patch test preparations.

The diagnostic tool to detect allergic contact sensitization is patch testing. Results of patch testing performed from January 1998 to December 2006 at the Massachusetts General Hospital (MGH) are analyzed and compared to our 1990-1997 data as well as to data from North American and European contact dermatitis societies. Data were collected from retrospective chart reviews and analyzed, focusing on the Hermal standard tray. The most common sensitizers were fragrance mix (18.3%) and nickel (16.7%). Significant increases over time were seen for balsam of Peru (p < .0005; CI, 1.34-2.76) and wool alcohols (p = .002; CI, 1.38-4.38) while gender-related statistical predominance was seen for nickel in females (p < .0005; CI, 2.92-8.20) and for epoxy resin in males (p < .0005; CI, 0.14-0.58). Our findings are similar to those of the North American and European contact dermatitis societies. The retrospective study sample was drawn from a selected group of referred patients that may not be representative of the general population. Analysis of data focused on the Hermal standard tray and might not reflect trends resulting from additional allergens in supplemental trays. Sensitization rates and the most important allergens at MGH have been stable over the past 17 years.

iodopropynyl butylcarbamate (IPBC), a commonly used preservative, is found in industrial and personal care products. to evaluate prevalence, clinical relevance, occupational relationship, and sources of positive reactions to IPBC in patients in North America. the North American Contact Dermatitis Group (NACDG) tested IPBC 0.1% and/or 0.5% in petrolatum (pet) between 1998 and 2008. Two patient groups of interest were defined, based on patch-test reactions to IPBC: weak (+) reactors and strong (++ or +++) reactors. Patient characteristics, site(s) of dermatitis, sources of positive reactions, clinical relevance, and occupational relevance to IPBC were tabulated. of the 25,321 patients tested, there were 226 (0.9%) weak reactors and 67 (0.3%) strong reactors. For IPBC-positive patients, the most frequent sites of dermatitis were scattered generalized distribution, hands, and arms. The majority (> 50%) of currently relevant reactions were to personal care products, and most reactions (> 90%) were not related to occupation. Only four of the strong reactors had definite clinical relevance (positive use-test reaction or positive patch-test reaction to a product containing IPBC). The frequency of positive reactions increased (0.2% vs 1.5%) when the higher concentration of IPBC was utilized, but most (> 64%) were weak reactions, of which some were likely irritant. allergy to IPBC is relatively uncommon. When clinically relevant, personal care products were the most likely allergen source. Because IPBC is a marginal irritant, caution should be utilized when testing with higher concentrations of IPBC (≥ 0.5% pet) and when interpreting weak (+) reactions. Verification of clinical relevance by use test or repeat patch testing or both is also important.

Methylchloroisothiazolinone/methylisothiazolinone (MCI/MI) and methylisothiazolinone (MI) contact allergies are rising dramatically. Moreover, 100 ppm of MCI/MI patch test might not detect an important number of MCI/MI and MI allergies. This study aimed to present the prevalence of contact allergy to both preservatives in an area of Spain and to investigate if 100 ppm of MCI/MI is an adequate concentration for a proper diagnosis. A prospective study was conducted from October 2011 to September 2013. All patients were patch tested with the Spanish baseline series (containing 100 ppm of MCI/MI) and with 200 ppm of MCI/MI and 2000 ppm of MI. A total of 490 patients were patch tested. The MCI/MI prevalence was 10% and increased from 7.8% in last term of 2011 to 14.3% in the first 9 months of 2013. The MI prevalence was 4.5% and increased from 1% to 7.7% in the same period. One hundred parts per million of MCI/MI could not diagnose 24.5% of MCI/MI allergies. All MI allergies were detected by 200 ppm of MCI/MI, whereas only 68.2% were positive to 100-ppm concentration. For a correct diagnosis of MCI/MI and MI contact allergies, we advocate increasing the MCI/MI patch test concentration to 200 ppm along with a temporal inclusion of MI in the North American Contact Dermatitis Group baseline series.

Both active and inactive ingredients in sunscreen may cause contact dermatitis. This study aimed to describe allergens associated with a sunscreen source. A cross-sectional analysis of patients patch tested by the North American Contact Dermatitis Group between 2001 and 2010 was performed. Of 23,908 patients patch tested, 219 (0.9%) had sunscreen coded as an allergen source. Patients who were male, with occupational dermatitis, or older (older than 40 years) had significantly lower rates of allergic reactions to sunscreens; the most commonly affected areas were the face and exposed sites (P < 0.0001). The top 3 most frequent allergens in sunscreens were benzophenone-3 (70.2% for 10% concentration, 64.4% for 3% concentration), DL-alpha-tocopherol (4.8%), and fragrance mix I (4.0%). Less than 40% of positive patch test reactions were detected by the North American Contact Dermatitis Group screening series of 65 to 70 allergens. A supplemental antigen series is important in detecting allergy to sunscreens.

Allergic and irritant contact dermatitis to food is likely underreported. To characterize relevant allergens and irritants associated with food in patients referred to the North American Contact Dermatitis Group (NACDG) for patch testing. Retrospective analysis of cross-sectional data from the NACDG from 2001 to 2004. Of 10,061 patch-tested patients, 109 (1.1%) had a total of 122 reactions associated with food. Approximately two-thirds of patients (66%) were female, and one-third (36%) were atopic. The hands were the most common sites of dermatitis (36.7%). There were 78 currently relevant (definite, probable, or possible) allergic reactions to NACDG standard series allergens with a food source; the most common allergen was nickel (48.7%), followed by Myroxilon pereirae (balsam of Peru) (20.6%) and propylene glycol (6.4%). Twenty allergic reactions to non-NACDG standard allergens and 24 relevant food irritants were also identified. Overall, 21% (25 of 122) of all reactions (irritant and allergic) were occupation related; the majority of these (17 of 25) were relevant irritant reactions. Cooks were the most commonly affected occupational group (40%). In this limited data set, nickel, Myroxilon pereirae, and propylene glycol were the most common allergens identified with a food source. Of food-related occupational disease, irritation was more common than allergy.

The most common differential diagnoses for patients presenting with lip dermatitis or inflammation include atopic, allergic, and irritant contact dermatitis. Patch testing can be performed to identify the allergic contact conditions. To report North American Contact Dermatitis Group (NACDG) patch-test results of patients who presented for patch testing with only lip involvement from 2001 to 2004. Patient characteristics, allergen frequencies, relevance, final diagnoses, and relevant allergic sources not in the NACDG screening series were evaluated. The NACDG 2001-2004 database was used to select patients presenting with only lip involvement. Of 10,061 patients tested, 2% (n = 196) had lips as the sole involved site. Most (84.2%) were women. After patch testing, 38.3% (n = 75) were diagnosed with allergic contact cheilitis. Fragrance mix, Myroxilon pereirae, and nickel were the most common relevant allergens. Of 75 patients, 27 (36%) had relevant positive patch-test reactions to items not on the NACDG series; lipstick and cosmetics were the predominant sources. Patch testing is valuable in the evaluation and identification of contact allergy in patients referred for lip dermatitis. The use of supplementary allergens based on history and exposure is important in the identification of additional relevant allergens. Over a third of patients with contact allergy had other factors, such as irritant dermatitis, considered relevant to their condition.

Allergic contact dermatitis is a significant cause of cutaneous disease affecting many individuals in the home and at the workplace. Patch testing is the most worthwhile diagnostic tool for the evaluation of patients with suspected allergic contact dermatitis. This study reports the results of patch testing from January 1, 2001, to December 31, 2002, by the North American Contact Dermatitis Group (NACDG). Patients were tested with an extended screening series of 65 allergens. A standardized patch-testing technique was used. Data from these patients were recorded on a standardized computer entry form and analyzed. Sixty-five allergens were tested on 4,913 patients. The top 10 allergens remain the same in this study period as in the 1999-2000 study period: nickel sulfate (16.7%), neomycin (11.6%), Myroxilon pereirae (balsam of Peru) (11.6%), fragrance mix (10.4%), thimerosal (10.2%), sodium gold thiosulfate (10.2%), quaternium-15 (9.3%), formaldehyde (8.4%), bacitracin (7.9%), and cobalt chloride (7.4%). Of the 4,913 patients tested, 69% had at least one positive allergic patch-test reaction. Of all patients, 15.8% had occupation-related dermatitis; 15.4% were determined to have irritant contact dermatitis, and 11.1% of the 15.4% had a relevant reaction to an occupational irritant. Of all patients tested, 16.7% had a relevant reaction to an allergen not in the NACDG standard series, and 5.5% had a relevant reaction to an occupational allergen not in the standard series. Our findings once again reinforce the need for a more comprehensive group of diagnostic allergens than those found in the standard screening kits. The usefulness of patch testing is enhanced when a greater number of allergens are tested, especially nonstandard allergens occupationally encountered.

Chemicals used in leather tanning, rubber processing, and/or adhesives are the most often-cited culprits in footwear dermatitis. Patch testing patients with suspected shoe dermatitis is essential for diagnosis and management. The four goals for this study were to (1) determine the frequency of allergens associated with a shoe source in North American Contact Dermatitis Group (NACDG) patients with footwear allergic contact dermatitis; (2) compare these results to allergen frequencies from other published studies; (3) quantify the number of shoe-related reactions that were not identified with the NACDG standard series; and (4) identify relevant allergens not included on the NACDG standard series, based on data from other published studies. The NACDG patch-tested 10,061 patients between 2001 and 2004. Data were retrospectively analyzed by (1) allergen source coded as "shoe," (2) site of dermatitis as "feet," and (3) diagnosis of "allergic contact dermatitis." Among the 109 NACDG patients with allergic contact dermatitis (ACD) of the foot and a shoe source of allergens, p-tertiary butylphenol formaldehyde resin, an adhesive, was the most common allergen, accounting for 24.7% of positive patch-test results, followed by potassium dichromate (17.5%) and carba mix (11.7%). When the data were examined according to groups of allergens, rubber chemicals (40.4%) were the most frequent allergens, followed by adhesives (32.5%), and leather components (20.1%). When data from published studies were pooled, potassium dichromate (31.5%) was the most frequent allergen, followed by p-tertiary butylphenol formaldehyde resin (17.1%) and cobalt chloride (12.9%). NACDG patients were statistically more likely to have positive patch-test reactions to p-tertiary butylphenol formaldehyde resin and statistically less likely to have a positive patch-test reaction to potassium dichromate than patients represented in pooled data from past studies. Nineteen (17.4%) of the 109 NACDG patients with ACD of the foot and a shoe source of allergens were identified as having a shoe source of a relevant allergen not included in the NACDG standard series. In NACDG patients, the most common individual shoe allergen was p-tertiary butylphenol formaldehyde resin. As a group, rubber chemicals were most common, a finding consistent with those of other studies.

Allergy to topical anesthetics is not uncommon. The cross-reactivity among topical anesthetics and the screening value of benzocaine alone are not well understood. The goals for this study were: (1) to evaluate the frequency and pattern of allergic patch-test reactions to topical anesthetics, using North American Contact Dermatitis Group (NACDG) data, and (2) to compare these results to allergen frequencies from other published studies. The NACDG patch-tested 10,061 patients between 2001 and 2004. In this analysis patients were included who had positive patch-test reactions to one or more of the following: benzocaine, lidocaine, dibucaine, tetracaine, and prilocaine. Of patch-tested patients, 344 (3.4%) had an allergic reaction to at least one anesthetic. Of those, 320 (93.0%) had an allergic reaction to only one topical anesthetic. Overall, reactions to benzocaine (50.0%, 172 of 344) were most prevalent, followed by reactions to dibucaine (27.9%, 96 of 344); however, reactions to dibucaine were significantly more frequent in Canada than in the United States (relative risk [RR], 2.31; 95% confidence interval [CI], 1.67-3.20; p < .0001). Of patients reacting to more than one anesthetic, most (79%, 19 of 24) reacted to both an amide and an ester. Of the topical anesthetics tested, benzocaine was the most frequent allergen overall. Over 50% of allergic reactions to topical anesthetics in this study would have been missed had benzocaine been used as a single screening agent. Cross-reactivity patterns were not consistent with structural groups.

Allergic contact dermatitis is a significant cause of both occupational and non-occupational skin disease. Patch testing is an important diagnostic tool for the determination of responsible allergens. This study reports the results of patch testing by the North American Contact Dermatitis Group from January 1, 2003, to December 31, 2004. At 13 centers in North America, patients were tested with the same screening series of 65 allergens, with a standardized patch-testing technique. Data were recorded on standardized forms and manually verified and entered. Descriptive frequencies were calculated, and trends were analyzed with chi-square statistics. A total of 5,148 patients were tested. Of these, 3,432 (66.7%) had at least one positive reaction, 2,284 (44.4%) were ultimately determined to have primary allergic contact dermatitis, and 676 (13.1%) had occupation-related skin disease. There were 9,762 positive allergic reactions. Compared to the previous reporting period (2001-2002), allergies to nickel, budesonide, mercaptobenzothiazole, and paraben mix were at least 1.12 times more common (all p values < .03). Compared with the previous 8 years (1994-2002), only the prevalence rates of allergies to nickel and budesonide were statistically significantly higher (p values < .003). Allergic contact dermatitis from nickel and budesonide may be increasing in North America. These results again underscore the value of patch-testing with many allergens.

Allergic contact dermatitis can be manifest as an eruption confined to the eyelids. In regard to this specific presentation, only limited information on which to base the selection of patch tests for proper evaluation is available. To identify the contact allergens most frequently found to be both patch test positive and relevant when only the eyelids are involved. Data collected from 2003 to 2004 by the North American Contact Dermatitis Group (NACDG) were analyzed for relevant allergens in the setting of dermatitis on the eyelids only. Data on eyelid dermatitis patients whose relevant allergens were not among the 65 allergens used for screening during this study period were also tabulated. Data showed that 268 patients had only eyelid dermatitis and a final diagnosis of allergic contact dermatitis. In 193 (72%) of these, reactions were of current relevance and were identified from a screening series of 65 allergens. The top 26 allergens identified 65% of cases (175 cases). Gold was the most frequently encountered allergen (22 of 175 cases [12.5%]). Of the 268 cases, 33 showed relevant reactions to an allergen that was not among the 65 NACDG standard screening allergens. No specific allergen was identified in the remaining 42 cases. The top 26 allergens identified in this study represent a potential eyelid dermatitis screening series.

The North American Contact Dermatitis Group (NACDG) tests patients who have suspected allergic contact dermatitis with a broad series of screening allergens, and publishes periodic reports of its data. To report the NACDG patch-test results from January 1, 2005, to December 31, 2006, and to compare results to pooled test data from the previous 10 years. Standardized patch testing with 65 allergens was used at 13 centers in North America. Chi-square statistics were utilized for comparisons with previous NACDG data. NACDG patch-tested 4,454 patients; 12.3% (557) had an occupation-related skin condition, and 65.3% (2,907) had at least one allergic patch-test reaction. The 15 most frequently positive allergens were nickel sulfate (19.0%), Myroxilon pereirae (balsam of Peru, 11.9%), fragrance mix I (11.5%), quaternium-15 (10.3%), neomycin (10.0%), bacitracin (9.2%), formaldehyde (9.0%), cobalt chloride (8.4%), methyldibromoglutaronitrile/phenoxyethanol (5.8%), p-phenylenediamine (5.0%), potassium dichromate (4.8%), carba mix (3.9%), thiuram mix (3.9%), diazolidinylurea (3.7%), and 2-bromo-2-nitropropane-1,3-diol (3.4%). As compared to the 1994-2004 data, there were significant increases in rates of positivity to nickel, quaternium-15, potassium dichromate, lidocaine, and tea tree oil. Of patch-tested patients, 22.9% (1,019) had a relevant positive reaction to a supplementary allergen; 4.9% (219) had an occupationally relevant positive reaction to a supplementary allergen. Nickel has been the most frequently positive allergen detected by the NACDG; rates significantly increased in the current study period and most reactions were clinically relevant. Other common allergens were topical antibiotics, preservatives, fragrance mix I and paraphenylenediamine. Testing with an expanded allergen series and supplementary allergens enhances detection of relevant positive allergens.

Background: Allergic contact dermatitis is common in children. Epicutaneous patch testing is an important tool for identifying responsible allergens. Objective: The objective of this study was to provide the patch test results from children (aged ≤18 years) examined by the North American Contact Dermatitis Group from 2005 to 2012. Methods: This is a retrospective analysis of children patch-tested with the North American Contact Dermatitis Group 65- or 70-allergen series. Frequencies and counts were compared with previously published data (2001-2004) using χ statistics. Conclusions: A total of 883 children were tested during the study period. A percentage of 62.3% had ≥1 positive patch test and 56.7% had ≥1 relevant positive patch test. Frequencies of positive patch test and relevant positive patch test reaction were highest with nickel sulfate (28.1/25.6), cobalt chloride (12.3/9.1), neomycin sulfate (7.1/6.6), balsam of Peru (5.7/5.5), and lanolin alcohol 50% petrolatum vehicle (5.5/5.1). The ≥1 positive patch test and ≥1 relevant positive patch test in the children did not differ significantly from adults (≥19 years) or from previously tested children (2001-2004). The percentage of clinically relevant positive patch tests for 27 allergens differed significantly between the children and adults. A total of 23.6% of children had a relevant positive reaction to at least 1 supplemental allergen. Differences in positive patch test and relevant positive patch test frequencies between children and adults as well as test periods confirm the importance of reporting periodic updates of patch testing in children to enhance clinicians' vigilance to clinically important allergens.

The North American Contact Dermatitis Group (NACDG) tests patients with suspected allergic contact dermatitis to a broad series of screening allergens and publishes periodic reports. The aims of this study were to report the NACDG patch-testing results from January 1, 2007, to December 31, 2008, and to compare results to pooled test data from the previous 2 and 10 years to analyze trends in allergen sensitivity. Standardized patch testing with 65 allergens was used at 13 centers in North America. χ analysis was used for comparisons. A total of 5085 patients were tested; 11.8% (598) had an occupationally related skin condition, and 65.3% (3319) had at least 1 allergic patch test reaction, which is identical to the NACDG data from 2005 to 2006. The top 15 most frequently positive allergens were nickel sulfate (19.5%), Myroxylon pereirae (11.0%), neomycin (10.1%), fragrance mix I (9.4%), quaternium-15 (8.6%), cobalt chloride (8.4%), bacitracin (7.9%), formaldehyde (7.7%), methyldibromoglutaronitrile/phenoxyethanol (5.5%), p-phenylenediamine (5.3%), propolis (4.9%), carba mix (4.5%), potassium dichromate (4.1%), fragrance mix II (3.6%), and methylchloroisothiazolinone/methylisothiazolinone (3.6%). There were significant increases in positivity rates to nickel, methylchloroisothiazolinone/methylisothiazolinone, and benzophenone-3. During the same period of study, there were significant decreases in positivity rates to neomycin, fragrance mix I, formaldehyde, thiuram mix, cinnamic aldehyde, propylene glycol, epoxy resin, diazolidinyl urea, amidoamine, ethylenediamine, benzocaine, p-tert-butylphenol formaldehyde resin, dimethylol dimethyl hydantoin, cocamidopropyl betaine, glutaraldehyde, mercaptobenzothiazole, tosylamide formaldehyde resin, budesonide, disperse blue 106, mercapto mix, and chloroxylenol. Twenty-four percent (1221) had a relevant positive reaction to a non-NACDG supplementary allergen; and 180 of these reactions were occupationally relevant. Periodic analysis, surveillance, and publication of multicenter study data sets document trends in allergen reactivity incidence assessed in the patch test clinic setting and provide information on new allergens of relevance.

Background: Patch testing is an important diagnostic tool for determination of substances responsible for allergic contact dermatitis. Objective: This study reports the North American Contact Dermatitis Group (NACDG) patch testing results from January 1, 2009, to December 31, 2010. Methods: At 12 centers in North America, patients were tested in a standardized manner with a screening series of 70 allergens. Data were manually verified and entered into a central database. Descriptive frequencies were calculated, and trends were analyzed using χ2 statistics. Results: A total of 4308 patients were tested. Of these, 2614 (60.7%) had at least 1 positive reaction, and 2284 (46.3%) were ultimately determined to have a primary diagnosis of allergic contact dermatitis. Four hundred twenty-seven (9.9%) patients had occupationally related skin disease. There were 6855 positive allergic reactions. As compared with the previous reporting period (2007-2008), the positive reaction rates statistically decreased for 20 allergens (nickel, neomycin, Myroxylon pereirae, cobalt, formaldehyde, quaternium 15, methydibromoglutaronitrile/phenoxyethanol, methylchlorisothiazolinone/methylisothiazolinone, potassium dichromate, diazolidinyl urea, propolis, dimethylol dimethylhydantoin, 2-bromo-2-nitro-1,3-propanediol, methyl methacrylate, ethyl acrylate, glyceryl thioglycolate, dibucaine, amidoamine, clobetasol, and dimethyloldihydroxyethyleneurea; P < 0.05) and statistically increased for 4 allergens (fragrance mix II, iodopropynyl butylcarbamate, propylene glycol, and benzocaine; P < 0.05). Approximately one quarter of tested patients had at least 1 relevant allergic reaction to a non-NACDG allergen. Hypothetically, approximately one quarter of reactions detected by NACDG allergens would have been missed by TRUE TEST (SmartPractice Denmark, Hillerød, Denmark). Conclusions: These results affirm the value of patch testing with many allergens.

The state of allergic contact dermatitis (ACD) education has not been formally examined since the original study done by High and Cruz (Am J Contact Dermat. 2003;14(4):195-199). The objectives of the study were to characterize the current state of ACD and patch-testing education in US dermatology residency programs and to determine if there has been any significant improvement over the past 8 years. This was a survey of ACD education and patch-testing practices in US dermatology residency programs. Surveys were sent to program directors and chief residents at all 112 US dermatology residency programs. Of the 224 surveys sent out, 105 (46.88%) were returned. There were several statistically significant changes from the 2002 survey. More faculty members who are designated as ACD experts are now members of the American Contact Dermatitis Society. Fewer programs now routinely review contact dermatitis-specific journals. Residents are now more likely to receive didactic lectures on ACD. Program directors estimated graduating residents will now be less likely to perform the TRUE Test in practice, and although not statistically significant, program directors also estimated an increase in the number of residents who will use expanded tests. Although some areas of ACD education have improved over the past 8 years, opportunities to further improve remain.

Toxicology endeavors to predict the potential of materials to cause adverse health (and environmental) effects and to assess the risk(s) associated with exposure. For skin sensitizers, the local lymph node assay was the first method to be fully and independently validated, as well as the first to offer an objective end point with a quantitative measure of sensitizing potency (in addition to hazard identification). Fifteen years later, it serves as the primary standard for the development of in vitro/in chemico/in silico alternatives.

Methyldibromoglutaronitrile/phenoxyethanol (Euxyl K 400) is a preservative found in both personal care products and industrial sources. Although Euxyl K 400 initially appeared to have low sensitizing potential, increased prevalence of contact allergy to Euxyl K 400 led to regulatory intervention. This review summarizes the history, epidemiology, and management of contact allergy to Euxyl K 400. Issues related to patch-test preparations are also discussed. © 2011 American Contact Dermatitis Society. All Rights Reserved.