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Publications (4)13.27 Total impact

  • Kapil Bhargava · Jonathan M White · Ian R White

    No preview · Article · Nov 2012 · Contact Dermatitis
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    ABSTRACT: The cosmetic industry producing hair dyes has, for many years, recommended that their consumers perform 'a hair dye allergy self-test' or similar prior to hair dyeing, to identify individuals who are likely to react upon subsequent hair dyeing. This review offers important information on the requirements for correct validation of screening tests, and concludes that, in its present form, the hair dye self-test has severe limitations: (i) it is not a screening test but a diagnostic test; (ii) it has not been validated according to basic criteria defined by scientists; (iii) it has been evaluated in the wrong population group; (iv) skin reactions have been read by dermatologists and not by the targeted group (consumers and hairdressers); (v) hair dyes contain strong and extreme sensitizers that are left on the skin in high concentrations, potentially resulting in active sensitization; and (vi) recommendations and instructions on how to perform the hair dye self-test vary greatly even among products from the same company, again suggesting that the basis for safe use of the test has not been determined. If the use of a hair dye self-test to predict contact sensitization becomes widespread, there is severe risk that a tool has been marketed that may cause morbidity in European consumers.
    No preview · Article · Jun 2012 · Contact Dermatitis
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    ABSTRACT: Positive patch test reactions to p-phenylenediamine (PPD) are common. PPD is used in oxidative hair dyes and is also present in dark henna temporary 'tattoos'. Cross-sensitization to other contact allergens may occur. Because subjects sensitized to PPD are at risk of clinically severe reactions upon hair dyeing, there is a need for 'current' prevalence data on PPD sensitization. To compare PPD patch test results from dermatitis patients tested between 2003 and 2007 in 10 European patch test centres and to analyse the causes and determine relevance of positive PPD patch test reactions. Patch testing was performed using PPD (1% free base in petrolatum from Trolab (Almirall Hermal GmbH, Reinbeck, Germany) or Chemotechnique (Malmö, Sweden), equivalent to 0.090 mg/cm(2) in the TRUE test from MEKOS Laboratories AS). Statistical analysis was performed using the chi-squared test. The weighted average prevalence was 4.6% among 21 515 patients. PPD sensitization occurred more often in centres located in Central and Southern Europe than in Scandinavian centres (odds ratio = 2.40; 95% confidence interval = 2.07-2.78). The overall proportion of positive patch test reactions to PPD that were registered as being of either current or 'past' relevance was high (weighted average 53.6% and 20.3%, respectively). Consumer hair dyeing was the most prominent cause of PPD sensitization (weighted average 41.8%). Furthermore, occupational hair dye exposure (10.6%) and cross-sensitization to textile dyes (12.6%) were frequently reported. PPD sensitization caused by exposure to hair dyes is frequent and remains a present problem for patients visiting contact dermatitis clinics, especially in patch test centres located in Central and Southern Europe.
    Full-text · Article · Jul 2009 · Contact Dermatitis
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    ABSTRACT: Over the 20th century, several contact allergy epidemics arose in Western Europe. Today, industries use various assays to determine the sensitization potential of new ingredients and thereby prevent new contact allergy outbreaks. This study debates acceptable risk of sensitization in the general population by using a new epidemiological tool. The clinical epidemiology (CE) and drug utilization research (DUR) method recently estimated the 10-year contact allergy prevalence in the general population in Germany and Denmark based on patch test reading data in combination with an estimate of the number of persons eligible for patch testing each year based on patch test sales data. A reverse CE-DUR was performed to make delineations between the 10-year prevalence of contact allergy in the general population and the corresponding theoretical prevalences of contact allergy observed among patients with dermatitis in Denmark and Germany. Results indicated that if 1/100 subjects in the general population in Denmark and Germany had contact allergy; dermatologists would observe a prevalence of contact allergy among dermatitis patients was between 4.5-8.0% and 2.5-10.4%, respectively. The reverse CE-DUR approach can be used to alert public health authorities if the estimated number of sensitized persons in the general population is above a certain threshold.
    No preview · Article · May 2009 · Regulatory Toxicology and Pharmacology