Plant Associated Irritant & Allergic Contact Dermatitis (Phytodermatitis).

With more than 350,000 plant species recognized and new species continually being identified, it is not surprising that humans contact plants or plant-containing products daily. The nearly endless list of potential exposures leaves us with a challenging task when attempting to categorize and study potential plant-related irritants and allergens. This article focused on laying a sound framework for understanding some of the more pertinent potential irritants and allergens.

Patch-test results of the North American Contact Dermatitis Group 2005-2006.

BACKGROUND: 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. OBJECTIVE: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Contact sensitization to fragrances in the general population: a Koch's approach may reveal the burden of disease.

BACKGROUND: Contact sensitization to fragrance mix (FM) I and Myroxylon pereirae (MP) is common among European patients with dermatitis. Recently, FM II was included in the European baseline series as an additional marker of fragrance sensitization. OBJECTIVES: This literature review aims to assess the prevalence of fragrance sensitization in the general population, and to suggest how future population-based studies and questionnaires should be constructed, better to assess the prevalence and burden of fragrance sensitization. This is of relevance as it is often difficult to establish causality in biological systems. METHODS: A systematic review of the literature was carried out by searching Pubmed-Medline, Biosis and contact dermatitis textbooks. RESULTS: Nineteen studies were identified, of which 13 were performed among adults. Sample sizes varied between 82 and 2545 tested subjects, and 11 648 subjects were tested in total. The median prevalence of FM and MP sensitization among adults was 2.3% (women, 1.7%; men, 1.3%) and 1.1% (women, 1.4%; men, 0%), respectively. CONCLUSIONS: Based on the reliability of patch test data from the general population and exposure data obtained from patients with dermatitis, the prevalence and burden of fragrance sensitization in the general population is significant.

Is incident sensitization to p-phenylenediamine related to particular exposure patterns? Results of a questionnaire study.

Evidence regarding the risk of active sensitization (AS) to p-phenylenediamine (PPD), patch tested 1% in petrolatum, is conflicting. The objective of this study was to evaluate the relative frequency of 'environmental' exposures and skin reactions to products potentially containing PPD in subgroups of patients with versus without newly diagnosed contact allergy (CA) to PPD upon retesting. Patients patch tested twice with PPD between 1996 and 2004 in the Information Network of Departments of Dermatology (IVDK) network were identified and classified into 4 groups, according to the 2 test results with PPD at D3. A self-administered questionnaire was mailed to 171 patients (response 57%). The frequency of exposure to 'henna tattoos', dark hair dyes, or textiles or work as hairdresser did not differ significantly between the groups. A significantly shorter median interval between the 2 patch tests was observed in the group with newly diagnosed PPD CA compared with the other groups (293 versus >700 days). The results of the study add new, if somewhat weak, evidence to the notion that patch testing with PPD may indeed carry some risk of AS, as environmental exposures to PPD were as common in the subgroup of patients with incident CA to PPD as in the remaining patients.