Mihaly Matura

Karolinska Institutet, Solna, Stockholm, Sweden

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Publications (35)86.77 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Disperse dyes, which are used for colouring synthetic textile fibres, are well-known contact sensitisers. To investigate the outcome of patch-testing with a textile dye mix (TDM) at 7 dermatology clinics in Sweden, a TDM tested at 2 concentrations was included into the baseline series during one year. The mix consisted of Disperse (D) Blue 35, D Yellow 3, D Orange 1 and 3, D Red 1 and 17, all 1.0%, and D Blue 106 and D Blue 124, each 0.3% in the mix 6.6% and 1.0% each in the mix 8.0%. In 2,122 tested patients, contact allergy to the TDM 8.0% was found in 2.8% and to the TDM 6.6% in 2.5% of the patients. The contact allergy to the TDM could explain or contribute to the dermatitis in about 35% of the patients. Conclusion: contact allergy to the TDM is common and inclusion into the Swedish baseline series should be considered.
    Acta dermato-venereologica. 08/2014;
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    ABSTRACT: Abstract is missing (Short Communication).
    Acta dermato-venereologica. 06/2014;
  • Contact Dermatitis 05/2014; 70(5). · 2.93 Impact Factor
  • Contact Dermatitis 03/2014; 70(3):187-9. · 2.93 Impact Factor
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    ABSTRACT: In a multicentre study consecutively patch-tested dermatitis patients were tested simultaneously with 1.0% and 2.0% (w/v) formaldehyde in aqua applied with a micropipette (15 µl) to the filter paper disc in Finn Chambers (0.30 mg/cm2 and 0.60 mg/cm2, respectively). A total of 2,122 dermatitis patients were patch-tested. In all, 77 (3.6%) patients reacted positively to formaldehyde; 37 reacted only to 2.0%, 35 reacted to both concentrations and 5 patients reacted only to 1.0%. Significantly more patients were thus diagnosed with contact allergy to formaldehyde with 2.0% compared to 1.0% (p < 0.001) without causing more irritant reactions. The detected number of isolated allergic reactions to the 2 formaldehyde-releasers in the Swedish baseline series and not to formaldehyde itself raises the question whether quaternium-15 1.0% and diazolidinyl urea 2.0% should be present in the Swedish baseline series.
    Acta Dermato-Venereologica 12/2013;
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    ABSTRACT: According to EU legislation, 26 fragrance substance allergens must be labelled on cosmetic products. For 12 of them, the optimal patch test concentration/dose has not been evaluated. To establish the optimal patch test doses in mg/cm2 for the 12 fragrance substances that are not included in fragrance mix I or II in the European baseline patch test series. Patch testing with the 12 fragrance substances was performed in a stepwise manner encompassing up to five rounds in at least 100 dermatitis patients for each round. Before patch testing, an individual maximum concentration/dose was determined for each fragrance substance. The predetermined maximum patch test concentrations/doses could be tested for all 12 fragrance substances, with no observable adverse reactions being noted. For each fragrance substance investigated, it is recommended that half of the maximum patch test dose (mg/cm2) be used for aimed and screening patch testing.
    Contact Dermatitis 03/2012; 66(3):131-6. · 2.93 Impact Factor
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    ABSTRACT: Contact allergy to phenol-formaldehyde resins (PFRs) based on phenol and formaldehyde is not detected by a p-tertiary-butylphenol-formaldehyde resin (PTBP-FR) included in most baseline patch test series. To investigate the rate of contact allergy to PFR-2 (a mixture of monomers and dimers from a resol resin based on phenol and formaldehyde) in a Swedish population, and to investigate associated simultaneous allergic reactions. Five centres representing the Swedish Contact Dermatitis Research Group included PFR-2 in their patch test baseline series for a period of 1.5 years. Of 2504 patients tested, 27 (1.1%) reacted to PFR-2. Of those 27 individuals, 2 had a positive reaction to formaldehyde and 2 to PTBP-FR. Simultaneous allergic reactions were noted to colophonium in 6, to Myroxylon pereirae in 14, and to fragrance mix I in 15. The contact allergy frequency in the tested population (1.1%) merits its inclusion in the Swedish baseline series and possibly also in other baseline series. Simultaneous allergic reactions were noted to colophonium, M. pereirae, and fragrance mix I.
    Contact Dermatitis 07/2011; 65(1):34-7. · 2.93 Impact Factor
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    ABSTRACT: Sesquiterpene lactone mix detects contact allergy to these compounds present in the plant family Asteraceae. This marker is present in many baseline series. An additional marker is Compositae mix, which is not present in many baseline series. To investigate whether this allergen should be inserted into the Swedish baseline series, six dermatology centres representing the Swedish Contact Dermatitis Research Group included Compositae mix into their baseline series for 1.5 years. Of 2818 patients tested, 31 (1.1%) reacted to Compositae mix and 26 (0.9%) to Sesquiterpene lactone mix. Active sensitization to Compositae mix was noted in two cases. Only 0.4% of Asteraceae contact allergy cases would have been missed if Compositae mix had not been tested, a frequency too low to merit its inclusion in the baseline series. Due to obvious geographical differences in frequency in frequency of simultaneous allergic reactions to Compositae mix and Sesquiterpene lactone mix, the question as to whether specific baseline series (including Compositae mix or not as a "tail" substance) should be used in the different centres must be addressed. Another option could be to remove Sesquiterpene lactone mix from the baseline series and substitute it with Compositae mix.
    Acta Dermato-Venereologica 03/2011; 91(3):295-8.
  • Magnus Lindberg, Mihaly Matura
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    ABSTRACT: The technique of patch testing is well established for diagnosing contact allergy. New allergens are continously identified, and the method itself is constantly developing. The outcome of patch testing depends on several factors including the knowledge and skill of the testing dermatologist. In the present chapter, we discuss the different aspects of patch testing ranging from test systems, allergens, evaluation, and relevance to strategies for including new allergens in baseline series and for the clinical investigation of patients.
    12/2010: pages 439-464;
  • Contact Dermatitis 08/2010; 63(2):110-2. · 2.93 Impact Factor
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    ABSTRACT: Linalool is a widely used fragrance terpene. Pure linalool is not allergenic or a very weak allergen, but autoxidizes on air exposure and the oxidation products can cause contact allergy. Oxidized (ox.) linalool has previously been patch tested at a concentration of 2.0% in petrolatum (pet.) in 1511 patients, and 1.3% positive patch test reactions were observed. Objective: To investigate the optimal patch test concentration for detection of contact allergy to ox. linalool. Four concentrations of ox. linalool (2.0%, 4.0%, 6.0%, 11.0% pet.) were tested in 3418 consecutive dermatitis patients. Ox. linalool 2.0%, 4.0%, 6.0%, and 11.0% pet. detected positive patch test reactions in 0.83%, 3.2%, 5.3%, and 7.2% of the tested patients, respectively. The doubtful reactions increased with rising concentrations but relatively less, giving 5.1%, 6.4%, and 7.3% doubtful reactions, respectively, for ox. linalool 4.0%, 6.0%, and 11.0% pet. Few irritative reactions were seen. Raising the patch test concentration for ox. linalool gave a better detection of contact allergy, as many as 5-7% positive patch test reactions were detected. We suggest a patch test concentration of ox. linalool 6.0% pet. for future patch testing, giving a dose per unit area of 2.4 mg/cm(2) when 20 mg test substance is tested in small Finn Chambers.
    Contact Dermatitis 01/2010; 62(1):32-41. · 2.93 Impact Factor
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    ABSTRACT: Linalool and limonene are common fragrance terpenes that autoxidize on air exposure. The pure compounds are not allergenic but their oxidation products can cause contact allergy. Little has been investigated regarding the irritancy of oxidized terpenes. The aim of this study was to investigate the irritating effect of pure and oxidized R-limonene and linalool in concentration series and to study the MNIC (Maximum Non Irritant Concentration) of autoxidized linalool and limonene. Patch testing was performed in dermatitis patients and controls with sequentially diluted concentrations of oxidized and non-oxidized linalool, and oxidized and non-oxidized R-limonene. Readings were made with visual assessment and using laser Doppler imaging. The non-oxidized terpenes were non-irritating in all tested concentrations. Both linalool and especially R-limonene were more irritating after oxidation compared with the pure compounds. No difference in response was seen between dermatitis patients and controls. Autoxidation of the fragrance terpenes linalool and R-limonene increases irritation. Oxidized linalool is less irritating than oxidized R-limonene. In this study, we found no advantages in using laser Doppler technique compared with visual assessment.
    Contact Dermatitis 02/2009; 60(1):32-40. · 2.93 Impact Factor
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    ABSTRACT: This is part of an ongoing effort to investigate how autoxidation affects the sensitzing potential of terpene-based fragrances. We have previously shown that terpenes such as abeitic acid (diterpene), limonene and linalool (monoterpenes) form stable hydroperoxides when oxidized. These hydroperoxides have proved to be strong allergens. Its therefore of special interest to study the connection between formation of hydroperoxides caused by autoxidation of fragrance chemicals during handling and storage and an increased allergenic effect.Objective: To investigate the autoxidation of caryophyllene (sesquiterpene) and study its effect on the sensitizing capacity.Methods: Caryophyllene was exposed to air and the autoxidation was monitored by GC and HPLC. The major oxidation products were isolated and their structure determined. The allergenic activity of pure caryophyllene and its oxidation products was investigated in animal assays and clinical testing.Result: Only 10% of the staring material remained after 20 weeks of air exposure. The major oxidation product was caryophyllene oxide. Substantial amounts of formaldehyde were found in the oxidation mixture. Little or no hydroperoxides were detected in the total oxidation mixture. Caryophyllene oxide and oxidized caryophyllene showed a low sensitizing capacity in animals and very few positive reactions at patch testing.Conclusion: Caryophyllene is easily oxidized at air exposure. A low allergenic effect is observed in both sensitization studies and clinical testing. This is consistent with our earlier findings that the amount of hydroperoxides is important for the allergenic activity of autoxidized terpenes.
    Contact Dermatitis 01/2008; 50(3):191-192. · 2.93 Impact Factor
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    ABSTRACT: Terpenes are among the most widely used fragrances, found not only in fine fragrances but most often incorporated in domestic and occupational products. Terpenes oxidize easily at air-exposure. Our previous studies have proved that limonene, linalool and caryophyllene are not allergenic in themselves but easily form allergenic products due to autoxidation. The aim of this study was to study the frequency and characteristics of allergic reactions in Europe to some oxidized fragrance terpenes.Method: Consecutive dermatitis patients in six European dermatological centers were patch tested with oxidized terpenes. Questionnaires, standard and additional fragrance patch test materials were used in the diagnosis of fragrance allergy.Results: Oxidized limonene was tested in 2411, while oxidized linalool, linalool hydroperoxide, oxidized caryophyllene, caryophyllene oxide and oxidized myrcene in additional 1511 patients. Of the patients tested 2.6% showed positive reaction to oxidized limonene, 1.3% to oxidized linalool, 0.5% to oxidized caryophyllene and 1 patient to oxidized myrcene. 1.1% of the patients reacted to linalool hydroperoxide, while testing with caryophyllene oxide resulted in few positive Results: 60% of the patients reacting to oxidized terpenes had fragrance related contact allergy and/or positive history for fragrance related dermatitis.Conclusion: Oxidized limonene and linalool are common allergens in dermatitis patients tested consecutively in Europe. Our results indicate that autoxidation of fragrance terpenes contributes to fragrance allergy to a great extent. This observation emphasises the need of testing with chemicals that patients actually come in contact with and not only ingredients that were originally applied in the commercial formulations.
    Contact Dermatitis 01/2008; 50(3):146-147. · 2.93 Impact Factor
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    ABSTRACT: Linalool is one of the most frequently used fragrance chemicals in scented products and a large population is exposed to it. It is therefore important to study the allergenic properties of linalool, and the effect of autoxidation.Objectives: To study the autoxidation of linalool and identify formed oxidation products, to investigate the impact of autoxidation on the sensitizing capacity and to study the frequency of contact allergy to oxidized linalool among consecutive dermatitis patients.Methods: Linalool was air-exposed and the degradation followed with GC. Oxidation products were identified with GC-MS and NMR. Pure linalool, 2 different states of oxidized linalool and 3 oxidation products were tested for their sensitizing capacity in the local lymph node assay (LLNA). Consecutive dermatitis patients were patch-tested with oxidized linalool and a fraction of oxidized linalool.Results: Linalool started to decompose immediately when air-exposed. Several oxidation products were identified among which 3 (2 hydroperoxides and an alpha, beta-unsaturated aldehyde) contain structural features that make them potential allergens. LLNA showed that the 3 oxidation products were moderate allergens, and that the sensitizing potential of linalool increased with longer air-exposure times. In the patch-test study positive reactions were observed to oxidized linalool in 1.65% of the patients.Conclusions: The extensively used fragrance chemical linalool is not allergenic in itself. The autoxidation process that takes place at air-exposure leads to the formation of sensitizing oxidation products. The frequency of consecutive patients reacting to oxidized linalool shows that the experimental findings are clinically important.
    Contact Dermatitis 01/2008; 50(3):147-147. · 2.93 Impact Factor
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    ABSTRACT: Colophonium (gum rosin) consists of numerous compounds. We have previously shown that abietic acid (Fig. 1), the major compound in gum rosin, is oxidized to strong contact allergens at air exposure (1). The most potent allergen identified is 15-hydroperoxyabietic acid (15-HPA, Fig. 1), which was isolated as its methyl ester (Fig. 1) and used for patch testing (2, 3). The aim of this study was to confirm the previous postulate that methyl esterification of the carboxyl group in 15-HPA does not affect the allergenic activity.
    Contact Dermatitis 07/2007; 56(6):355-6. · 2.93 Impact Factor
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    ABSTRACT: Limonene, one of the most often used fragrance terpenes in any kind of scented products, is prone to air-oxidation. The oxidation products formed have a considerable sensitizing potential. In previous patch test studies on consecutively tested dermatitis patients, oxidized R-limonene has been proven to be a good and frequent indicator of fragrance-related contact allergy. The current study extends these investigations to 6 European clinics of dermatology, where the oxidation mixture of both enantiomers of limonene (R and S) have been tested in 2411 dermatitis patients. Altogether, 63 out of 2411 patients tested (2.6%) reacted to 1 or both the oxidized limonene preparations. Only 2.3% reacted to the oxidized R-limonene and 2.0% to the oxidized S-limonene. In 57% of the cases, simultaneous reactions were observed to both oxidation mixtures. Concomitant reactions to the fragrance mix, colophonium, Myroxylon pereirae, and fragrance-related contact allergy were common in patients reacting to 1 or both the oxidized limonene enantiomers. Our study provides clinical evidence for the importance of oxidation products of limonene in contact allergy. It seems advisable to screen consecutive dermatitis patients with oxidized limonene 3% petrolatum, although this patch test material is not yet commercially available.
    Contact Dermatitis 12/2006; 55(5):274-9. · 2.93 Impact Factor
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    ABSTRACT: Concomitant positive reactions to colophonium, oxidized limonene, and/or oxidized linalool are recorded in patch test studies. The main allergens in these patch test mixtures are hydroperoxides, which form antigens by a radical pathway. Theoretically, concomitant reactions can be explained not only by concomitant sensitization or by true cross-reactions but also by the hydroperoxides acting as oxidizing agents on skin proteins to form non-specific antigens without hapten-protein binding. The aim of this study was to explore concomitant reactions and cross-reactivity patterns among hydroperoxide haptens. We investigated whether individuals allergic to the main allergen in colophonium, 15-hydroperoxyabietic acid, would also react to limonene hydroperoxide or linalool hydroperoxide. Only 1 of 29 individuals reacted to more than 1 hydroperoxide. The cross-reactivity pattern among cumene hydroperoxide, limonene hydroperoxide, 1-(1-hydroperoxy-1-methylethyl) cyclohexene (cyclohexene hydroperoxide), and 15-hydroperoxydehydroabietic acid was investigated in guinea-pigs. No general cross-reactivity was observed. Cross-reactions between cumene hydroperoxide and cyclohexene hydroperoxide show that similarity in the overall structure and the way of antigen formation are needed. Quantum calculations were used to determine the formation energies of the intermediary radicals. We concluded that hydroperoxides form specific antigens and that formation of non-specific antigens is unlikely. The concomitant patch test reactions described in the literature are best explained as a result of multiple sensitizations.
    Contact Dermatitis 11/2006; 55(4):230-7. · 2.93 Impact Factor
  • S Kerre, M Matura, A Goossens
    Contact Dermatitis 09/2006; 55(2):117-8. · 2.93 Impact Factor
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    ABSTRACT: Fragrances are common causes of allergic contact dermatitis. beta-Caryophyllene is a sesquiterpene that is used as a fragrance chemical. Analogous to the monoterpenes R-limonene and linalool, it can be expected to autoxidize when air exposed. The aim of the present study was to investigate the autoxidation of beta-caryophyllene and to evaluate the effect on the contact allergenic activity. beta-Caryophyllene started to oxidize immediately when air exposed and after 5 weeks almost 50% of the original compound was consumed. Caryophyllene oxide was found to be the major oxidation product. Hydroperoxides of beta-caryophyllene could not be detected in the oxidation mixture. Caryophyllene oxide was shown to be an allergen of moderate strength and beta-caryophyllene air exposed for 10 weeks showed a weak sensitizing capacity in the local lymph node assay. The study reveals that the allergenic activity of beta-caryophyllene is affected by autoxidation, but to a lesser extent when compared to R-limonene and linalool. The present findings support our results in clinical studies showing oxidized beta-caryophyllene to be a rather rare sensitizer compared to oxidized R-limonene and linalool.
    Food and Chemical Toxicology 05/2006; 44(4):538-45. · 3.01 Impact Factor

Publication Stats

506 Citations
86.77 Total Impact Points

Institutions

  • 2010–2014
    • Karolinska Institutet
      • Institute of Environmental Medicine - IMM
      Solna, Stockholm, Sweden
  • 2011
    • Skåne University Hospital
      Malmö, Skåne, Sweden
    • Lund University
      • Occupational and Environmental Dermatology Unit
      Lund, Skane, Sweden
  • 2006–2010
    • Sahlgrenska University Hospital
      Goeteborg, Västra Götaland, Sweden
  • 2003–2010
    • University of Gothenburg
      Goeteborg, Västra Götaland, Sweden
  • 2008
    • Mid Sweden University
      Härnösand, Västernorrland, Sweden
  • 2000
    • Universitair Ziekenhuis Leuven
      • Department of Dermatology
      Leuven, VLG, Belgium
  • 1998
    • University of Leuven
      Louvain, Flanders, Belgium
  • 1997
    • Malmö University
      • Faculty of Odontology (OD)
      Malmö, Skåne, Sweden
    • Leuven University College
      Louvain, Flanders, Belgium