Cream treats sun damage

Last updated: Tuesday, January 13, 2009 Print

Applying a prescription cream (imiquimod) for 24 weeks is effective for the treatment of a type of skin lesion called actinic keratosis, caused by long-term exposure to the sun, according to researchers from Mount Sinai Medical Centre in New York.

Actinic keratosis is a slowly developing localised thickening of the outer layers of the skin as a result of chronic, prolonged exposure to the sun. It is a potentially malignant lesion and treatment includes surgical excision, cryotherapy and topical chemotherapy. Other names for it include senile keratosis, senile wart and solar keratosis. Locally it is found in Aldara cream.

How the study was done
For the research, Dr Mark Lebwohl and colleagues enrolled 20 patients with actinic keratosis into a 28-week trial. Fifteen patients completed the trial and five dropped out for reasons unrelated to treatment, the researchers report in the Journal of the American Academy of Dermatology.

Patients applied imiquimod 5% cream supplied in 250 milligram single-dose packages to affected areas on one side of the body and a placebo cream to the opposite side once a week for 24 weeks. Patients were assessed at 28 weeks.

Seven patients, or 46.7%, had marked improvement or better on the actively treated areas, while only one patient (6.7%) had improvement in areas treated with the placebo cream, the researchers report. The total number of lesions declined from an average of 1.93 to 1.47 on the actively treated side, while the number increased from 2.07 to 2.13 on the placebo side.

Of lesions treated with imiquimod cream, five of five mild cases remained mild; two of six moderate cases remained moderate, three improved to mild and one cleared; and three of four severe cases remained severe, while one improved to mild.

What the study revealed
Of lesions receiving placebo, one of three mild cases remained mild, while two worsened to moderate; seven of eight moderate cases remained moderate, while one improved to mild; and all eight cases rated as severe at baseline remained severe at follow-up. Side effects with imiquimod cream were minimal to nonexistent.

"We have used imiquimod once per week in routine clinical practice for periods over 1 year with good outcomes," Lebwohl said. "Mild redness is the main side effect and, with successful therapy, that fades." – (Reuters Health, January 2009)