[Mechanism of azelaic acid action in acne]

The physiopathologic mechanism of acne seems to be dependent on four main factors: a) sebum production and excretion; b) type of keratinization of the follicular channel; c) microbial colonization of the pilosebaceous unit and d) inflammatory reaction of the perifollicular area. Azelaic acid is effective in the treatment of acne because it possesses an activity against all of these factors. Azelaic acid is a competitive inhibitor of mitochondrial oxidoreductases and of 5 alpha-reductase, inhibiting the conversion of testosterone to 5-dehydrotestosterone. It also possesses bacteriostatic activity to both aerobic and anaerobic bacteria including Propionibacterium acnes. Azelaic acid is an anti-keratinizing agent, displaying antiproliferative cytostatic effects on keratinocytes and modulating the early and terminal phases of epidermal differentiation.