Tretinoin (all-trans-retinoic acid; Retin-A), a vitamin A metabolite used for years for topical treatment of acne, is now being used (without the approval of the US Food and Drug Administration) to improve the appearance of aging skin. Available by prescription in various concentrations in cream, gel and liquid formulations, tretinoin is chemically similar to isotretinoin (13-cis-retinoic acid; Accutane), an oral drug used for treatment of severe acne which has recently caused concern because of its teratogenicity (Morbid Mortal Weekly Rep, 37:171, March 25, 1988).

Tretinoin (tret' i noyn; all-trans-retinoic acid; Retin-A), a derivative of vitamin A, has been used for years for topical treatment of acne. More recently, it has also been used to improve the appearance of skin damaged by chronic exposure to the sun, although not approved for this indication by the US Food and Drug Administration.

Veltin Gel (Stiefel), a fixed-dose combination of the antibiotic clindamycin phosphate 1.2% and the retinoid tretinoin 0.025%, has been approved by the FDA for topical treatment of acne vulgaris in patients ≥12 years old. Another product containing the same active ingredients (Ziana) has been on the market since 2006.

The FDA has approved Twyneo (Galderma), a cream containing the retinoid tretinoin and the oxidizing agent benzoyl peroxide, for once-daily topical treatment of acne in patients ≥9 years old.

Topical tretinoin (all-trans-retinoic acid) has been used for years to treat skin damaged by chronic exposure to the sun (Medical Letter, 34:28, 1992). First approved by the FDA only for treatment of acne in concentrations ranging from 0.025% to 0.1% (Retin-A, and others), it has now been approved as an 0.05% formulation in an emollient cream base (Renova) for topical treatment of photodamaged skin. In recent years, alpha-hydroxy acids incorporated in some cosmetics have also been promoted as effective in improving the appearance of aging skin.

Adapalene (Differin - Galderma), a synthetic retinoid analog, has been marketed in the USA in a 0.1% gel formulation for topical treatment of acne vulgaris.

Azelaic acid, a naturally occurring heptanedicarboxylic acid, has been marketed in the USA as a 20% cream (Azelex - Allergan) for treatment of acne. The drug has been available in Europe for several years.

Tazarotene (taz ar' oh teen, Tazorac - Allergan), an acetylinic retinoid marketed for treatment of psoriasis (Medical Letter 1997; 39:105), is also available as a 0.1% gel and cream for treatment of acne.

The FDA has approved trifarotene 0.005% cream (Aklief – Galderma) for topical treatment of acne vulgaris in patients ≥9 years old. Trifarotene is the fourth topical retinoid to be approved in the US for treatment of acne; tretinoin (Retin-A, and others), adapalene (Differin, and generics), and tazarotene (Tazorac, and others) have been available by prescription for decades. Adapalene 0.1% gel has been available over the counter since 2016 for treatment of acne in patients ≥12 years old.

Acne is common among adolescents and adults. Guidelines for treatment of acne were last published by the American Academy of Dermatology in 2016.