Keratolytic Treatments for Acne: A Review

By: Ali Alikhan, MD, Mayo Clinic; and Howard I Maibach, MD, University of California School of Medicine

Posted: September 29, 2010, from the October 2010 issue of Cosmetics & Toiletries.

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Isotretinoin: Isotretinoin (Iso) remains a mainstay for severe, recalcitrant, nodulocystic acne, producing dramatic clearing and prolonged remissions. Its efficacy extends beyond the correction of hyperkeratinization to include actions on the sebaceous gland, i.e. decreased size and secretion; anti-comedogenic properties; and the creation of an unfavorable follicular environment for P. acnes.

A cumulative dose of 100–150 mg/kg Iso (see Mg/Kg Dose Response) is recommended during treatment course, with daily dosage ranging from 0.5–1 mg/kg/day. Lower daily doses may be associated with higher relapse rates. Nonetheless, to diminish possible retinoid flare, doses of 0.5 mg/day for the first month may be practical.

A recent trial suggested that intermittent Iso treatment may result in fewer side effects such as mucosal dryness, chapped lips and facial redness for those with moderate acne. Volunteers were treated with 0.5 mg/kg/day of Iso for either: the first 10 days of each month for six months, or daily during the first month and the first 10 days of each month for the next five months. Nevertheless, in severe acne, consistent daily usage (Iso 0.5 mg/kg/day for six months) displayed greater efficacy than intermittent usage patterns.⁷

Eruptive inflammatory attacks are common during the first month of Iso therapy, typically resolving without scarring. The most commonly reported adverse effects are mucocutaneous and cutaneous changes such as dryness around the lips, eyes, mouth and other mucosal surfaces. Serious side effects include hyperlipidemias, pseudotumor cerebri, hyperostosis, hepatotoxicity, premature epiphyseal closure and inflammatory bowel disease.

A number of ophthalmologic effects have been associated with Iso as well, including poor night vision, reversible corneal opacities and excessive glare. It should also be noted that Iso is a potent teratogen, a drug known to cause birth defects. Many reports of congenital abnormalities have surfaced. One investigation involving 154 pregnancies with fetal exposure to oral Iso resulted in 12 spontaneous abortions and 21 major malformations involving craniofacial, cardiac, thymic and neural structures.⁸