Lowering lesional surface pH in acne: a new treatment modality for Herpifix.

The acid skin surface pH has antimicrobial activities. Increased growth of Propionibacterium acnes contributes to the pathogenesis of acne. Therefore, the pH of inflammatory acne lesions was determined prior to and after lesional acidification employing Herpifix (Courage + Khazaka, Cologne, Germany), a microphoretic system. The pH was correlated with the number of acne lesions. A total of 30 volunteers with acne vulgaris participated in this crossover study applying either Herpifix or a dummy to inflammatory lesions. Prior to treatment, the pH of acne lesions was 5.7 +/- 0.2 (mean +/- SD) and 22 lesions (mean +/- 10) were counted in an 8 x 8 cm(2) facial surface area. Fifteen volunteers (group A) used Herpifix first for 3 weeks and then the dummy, while the other group of 15 volunteers (group B) used the dummy first and then Herpifix. In group A, the lesional surface pH and number of lesions decreased (p < 0.01) initially. When the dummy was used over a second 3-week treatment period, the skin surface pH and number of acne lesions increased. Findings for group B were vice versa. When both groups were compared at the end of the study, a significant difference in pH values (p < 0.001) and the number of acne lesions (p < 0.05) was obtained. Herpifix may be considered as a new therapeutic option for inflammatory acne.