07/15/11

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FROM THE WORLD CONGRESS OF DERMATOLOGY

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Vitals

Major Finding: Oral isotretinoin and topical tretinoin both reduced facial actinic keratoses by 74% after 6 months and 54% after 12 months.

Data Source: A 1-year randomized trial comparing the efficacy of low-dose oral isotretinoin to alternate-day tretinoin in 22 patients with photoaging.

Disclosures: The study was funded by the Sao Paulo State Research Foundation. Dr. Bagatin reported having no financial conflicts.

SEOUL, SOUTH KOREA – Low-dose oral isotretinoin and alternate-day tretinoin proved similarly effective for treatment of photoaging in a prospective randomized trial.

Treatment of photoaged skin is an off-label application for isotretinoin, but there have been a number of published favorable case series (J. Eur. Acad. Dermatol. Venereol. 2009;23:115-23).

Some dermatologists are prescribing it in more severe cases where teratogenicity is a nonissue. So Dr. Edileia Bagatin decided to put the potent oral retinoid to the test in a randomized comparison with tretinoin (Renova), a topical retinoid that does have a regulatory indication for photoaging.

The result of the 12-month study was a draw in terms of efficacy. The two treatment groups showed similar improvements in photoaging based upon blinded dermatologic evaluations, patient self-ratings, quality of life scores, and histologic findings.

And because the topical retinoid doesn't come with the baggage for which isotretinoin is notorious – including dyslipidemia, birth defects, liver dysfunction, depression, and inflammatory bowel disease – tretinoin has the clear advantage in most situations, said Dr. Bagatin at the World Congress of Dermatology.

The trial involved 22 patients, aged 50-75 years, with moderate to advanced photoaging. Nine of 11 subjects in each treatment arm were smokers.

Patients were assigned to either 20 mg/day of isotretinoin for 6 months followed by 0.05% tretinoin cream applied every other day for 6 months, or to alternate-day tretinoin for the full 12 months. All patients were instructed to use a moisturizing sunscreen twice daily.

The number of actinic keratoses on the face was reduced to a similar extent via both therapies: by an average of 74% after 6 months and 54% after 12 months. The number of AKs on the forearms dropped by an average of 42% with either therapy after 6 months, and by 61% after 12 months, according to Dr. Bagatin, of the Federal University of Sao Paulo (Brazil).

The patients themselves rated their wrinkles, skin elasticity, actinic keratoses, and freckles as significantly improved at both 6 and 12 months, with no significant difference between treatment arms. Median Dermatology Life Quality Index scores showed significant improvement over time, again with no difference between the two groups.

On histology, both groups displayed reductions in corneal layer thickness and elastosis, along with increased epidermal thickness; these changes were greater with time. There was also a significant reduction in p53 expression and an increase in collagen I, with both changes being greater at 12 months than 6 months.

The study was funded by the Sao Paulo State Research Foundation. Dr. Bagatin reported having no financial conflicts.

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