The application of benzoyl peroxide-sulfur lotions to normal and acne skin caused a minimal to moderate epidermal reaction and a moderate to marked dermal response consisting of vascular dilatation and a lymphocytic perivascular infiltrate. Benzoyl peroxide alone elicited predominantly dermal changes. This suggests that primary irritants can act at various levels of the skin.
The mode of action of "keratolytics" and their effect in acne vulgaris is briefly discussed.
Vasarinsh P. Benzoyl Peroxide—Sulfur LotionsA Histological Study. Arch Dermatol. 1968;98(2):183-187. doi:10.1001/archderm.1968.01610140081020