However, it has many positive qualities, including being gentle enough to use daily and is safe to use in pregnancy. It is antibacterial, comedolytic, keratolytic, and has antioxidant activity. Unfortunately, in the last decade the formulations of azelaic acid have not been changed considerably. The 20% cream, 15% gel, and 15% foam vehicles are often too irritating and drying to be used in the population it is intended for: those with rosacea, or with inflamed or sensitive skin.
Dr. Lily Talakoub
Azelaic acid is a dicarboxylic acid produced by Pityrosporum ovale. It inhibits the synthesis of cellular proteins and is bactericidal against Propionibacterium acnes and Staphylococcus epidermidis. Azelaic acid is both keratolytic and comedolytic by decreasing keratohyalin granules and reducing filaggrin in the epidermis. It not only scavenges free oxygen radicals, thereby reducing inflammation, but is also a tyrosinase inhibitor – making it a safe, non–hydroquinone-based alternative to skin lightening.
Azelaic acid has little toxicity, it is ingested regularly as it is found in wheat, barley, and rye. Topical side effects are usually mild and can subside with increased use. The most common side effects include erythema, local stinging, pruritus, scaling, and a burning sensation. It is considered safe in pregnancy and a great alternative to medications for acne in pregnant or nursing patients.
The largest constraint with azelaic acid preparations on the market – and most likely the reason it has not been more widely used for acne, rosacea, antiaging, and hyperpigmentation – is the formulation. The foam and gel preparations are irritating and difficult to use on dry or sensitive skin. The 20% cream preparations are slightly better tolerated; however, in vitro skin-penetration studies have shown that cutaneous penetration of azelaic acid is greater after application of a 15% gel (aqueous-based vehicle) and 15% foam (hydrophilic oil-in-water emulsion) as compared with the 20% cream formulations.
Dr. Naissan O. Wesley
In my clinical experience, azelaic acid can only be used in rosacea patients with oily or nonsensitive skin. The majority of my rosacea patients cannot tolerate the burning sensation, albeit transient and mild. Acne patients who do not have dry skin and pregnant patients with mild acne are a great population for integrating azelaic acid into an acne regimen. I also use azelaic acid as an alternative for mild melasma and lentigines in patients who are tapering off hydroquinone or cannot use hydroquinone. In the future, we need better, creamier, nonirritating formulations to be developed and more studies of higher concentrations of this acid for both prescription/patient at-home use, as well as more elegant in-office localized peel systems using azelaic acid.
Dr. Talakoub and Dr. Wesley are cocontributors to this column. Dr. Talakoub is in private practice in McLean, Va. Dr. Wesley practices dermatology in Beverly Hills, Calif. This month’s column is by Dr. Talakoub. Write to them at dermnews@mdedge.com. They had no relevant disclosures.
References
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