The relevancy of patch testing in the exploration of the cutaneous side effects of herbal medicine.

Background: Data on the cutaneous side effects of herbal medicine is scarce, especially with regard to allergy skin testing. Our objective was to determine the relevancy of patch testing in the exploration of the cutaneous side effects of herbal medicine. Material and Methods: A prospective study was conducted in the Department of Dermatology of the Hospital Institute of Social Hygiene of Dakar over a one-year period. Patch tests were given to patients with cutaneous side effects related to the exclusive use of herbal medicine. The plants recovered were turned into macerates and powders and mixed with Vaseline at concentrations of 5%, 20%, and 30%. Results: Patch tests were given to 31 of the 53 patients included. They were positive in 11 patients (35.48%). Positive patients displayed systemic eczema (n = 7/15 of cases), Stevens--Johnson syndrome (n = 2/3), contact eczema (n = 1/1), and fixed pigmented erythema (n = 1/2). Positive tests were obtained for 11 medicinal plants identified: Jatropha chevalieri (n = 2), Terminalia avicennoïde (n = 2), Detarium microcarpum, Acacia seyal, Acacia albida, Acacia italic, Sesamum indicum, Mangifera indica, Momordica charantia, Nauclea latifolia, and Anogeisius leiocarpus (in one case each). There was no statistically significant relationship between the type of cutaneous side effect and the test result (p = 0.388) and between the nature of the plant used and the test result (p = 0.402). Conclusion: In view of their high rates of positivity, patch tests could prove promising in the exploration of the cutaneous side effects of herbal medicine. [ABSTRACT FROM AUTHOR]