Comparison of racial distribution of photodermatoses in USA academic dermatology clinics: A multicenter retrospective analysis of 1080 patients over a 10-year period.

BACKGROUND: Previous studies at single academic institutions have identified variations in the prevalence of photodermatoses among racial groups. The purpose of the study was to compare the distribution of photodermatoses between Whites and Blacks at four academic medical centers in the USA. METHODS: A retrospective chart review was performed at four institutions' general dermatology clinics using diagnoses consistent with the International Classification of Disease (ICD), Ninth and Tenth Revisions, codes related to photodermatoses between August 2006 and August 2016. A total of 9736 charts were manually reviewed and classified. Analyses were performed analyzing the frequency of photodermatoses between Whites and Blacks in the pooled data. RESULTS: There were 1,080 patients with photodermatoses identified. Statistically significant differences in the frequency of photodermatoses between Whites and Blacks were identified for polymorphous light eruption (more common in Blacks), photoallergic contact dermatitis, phototoxic drug eruption, phytophotodermatitis, porphyria, and solar urticaria (more common in Whites). The most commonly diagnosed photodermatoses were polymorphous light eruption (total 672), and photodermatitis not otherwise specified (total 189). CONCLUSION: Our study demonstrated significantly higher proportions of polymorphous light eruption in Blacks, and higher proportions of photoallergic contact dermatitis, phototoxic drug eruptions, phytophotodermatitis, porphyrias, and solar urticaria in Whites.

Evaluation of photopatch test allergens for Indian patients of photodermatitis: preliminary results.

BACKGROUND: There is a strong need to develop a photopatch test tray suitable for Indian patients of photodermatitis as European/Scandinavian photopatch test trays may not be wholly relevant for them. AIM: We carried out this study using photoallergens relevant in the Indian context to determine their relevance in patients of photodermatitis. METHODS: Thirty patients (M:F, 23:7) between 19 and 76 years of age of photodermatitis and 10 controls were patch- and photopatch tested with 20 common photoallergens. In addition, the patients were also (photo) patch tested with articles of daily use as and when these were suspected to be the cause. RESULTS: Forty-three positive reactions to one or more antigens were seen in 22 (74%) patients. Fourteen positive photopatch tests to seven allergens were observed in 10 (33%) patients, and nine (30%) of them had a definite relevance. The most common contact allergen was fragrance mix (FM) (30%), followed by p-phenylenediamine (20%) and Parthenium hysterophorous (17%). The definite relevance of the patch- and photopatch tests could be correlated in 47% of these patients. CONCLUSIONS: FM is the most common contact and photocontact allergen among the various photopatch test antigens. Although differences in technique and evaluation make direct comparison between different centers difficult, still photopatch testing remains an integral part and gold standard for the work-up of the photosensitive patients.