Short-term topical benzoyl peroxide does not reduce cutaneous delayed-type hypersensitivity reactions or epidermal Langerhans cell density

Abstract

In a pilot study, we investigated the effect of topical benzoyl peroxide on cutaneous delayed-type hypersensitivity and on the number of epidermal Langerhans cells. Healthy volunteers and contact-allergic patients applied a 5% benzoyl peroxide cream to the inside of one forearm once daily for 5 days, and as a control the cream base to the other. Delayed-type hypersensitivity reactions were then tested on both forearms, in five volunteers using the Multitest Merieux and in the patients by patch testing with allergens previously shown to be positive. The Langerhans cells in skin biopsies from both forearms of three healthy volunteers and two contact-allergic patients were identified by the APAAP-method using anti-CD1a antibodies. No statistically significant difference was found in the scores of the Multitest Merieux and in the number of epidermal Langerhans cells between benzoyl peroxide- and cream base- treated skin, nor was the patch test reactivity reduced by the benzoyl peroxide treatment.