Other topical products with antimicrobial effects include azelaic acid and sodium sulfacetamide. Azelaic acid is a naturally occuring nine-carbon dicarboxylic acid. It is available for the treatment of acne in a 20% cream preparation. Azelaic acid has antimicrobial and weak anti-comedogenic effects. It reduces the production of keratohyalin granules in the pilosebaceous epithelium, thus normalizing ductal keratinocyte proliferation (62). Its anti-microbial effect is inferior to that of antibiotics or benzoyl peroxide (65). Azelaic acid can also decrease pigmentation by competing with tyrosinase (66). It may therefore be helpful for acne patients with post-inflammatory hyperpigmentation. It causes minimal erythema and does not produce the same degree of irritation as topical retinoids (62). Additionally, azelaic acid is safe for use in pregnancy.
Sulfur-sodium sulfacetamide is another well-tolerated topical antimicrobial. It is available as washes, bars, and creams. Sulfur presumably inhibits the growth of P. acnes by inhibiting its sustenance, para-aminobenzoic acid (PABA). The irritant effect on the skin causes keratolysis. The addition of sodium sulfacetamide lotion to sulfur has made its use more cosmetically acceptable.