The mainstays of therapy for actinic keratoses (AK) include cryosurgical destruction, curettage, topical fluorouracil, and trichloroacetic acid peels. Each of these modalities may be painful, and associated risks include scarring and pigmentary alterations. In the search for therapeutic alternatives, 5% imiquimod cream has been promising. Stockfleth et al demonstrate that 5% imiquimod cream was an effective patient-applied therapy for AK, particularly in those patients who had a brisk inflammatory response to treatment.
Chronological (intrinsic) aging affects the skin as it does other organ systems. The skin also undergoes extrinsic aging, mainly as a result of repeated UV radiation–induced photo-oxidative damage by reactive oxygen species. In this study, Naderi-Hachtroudi et al define the adaptive antioxidant enzymatic mechanisms that offer immediate protection against the oxidative assault following UV-B irradiation.
Basal cell carcinoma (BCC) is the most common cutaneous malignancy, and UV irradiation is commonly considered to be the single most important risk factor in the pathogenesis of BCC. Heckmann et al demonstrate the surprising finding that the anatomic distribution of BCC on the face is poorly correlated with cumulative UV exposure. Textural differences in the skin, such as reduced tension and dermal thickness, are offered as potential cofactors in the development of BCC on the face.
In this computer-assisted, quantitative image analysis of changes in blood vessel size and density, Chung et al demonstrate that extrinsically aged skin showed a progressive loss of upper dermal blood vessels associated with a reduction in average caliber. Intrinsically aged skin, on the other hand, maintained a normal blood vessel density, although the blood vessels were of reduced caliber. These findings suggest a possible role for angiogenic mediators in the treatment of extrinsically aged skin.
Sun-exposed skin in a 25-year-old subject (A) and a 77-year-old subject (B).
Topical retinoids have demonstrated utility in the treatment of some clinical features of extrinsically aged skin. In this study, Phillips et al demonstrate the efficacy of tazarotene in improving 8 signs of photodamage, including fine wrinkling, mottled hyperpigmentation, lentigines, elastosis, pore size, irregular depigmentation, tactile roughness, and coarse wrinkling.
Nonablative photorejuvenation techniques promise to stimulate neocollagenesis and improve the appearance of extrinsically aged skin without the risks of previous laser approaches to photoaging. In this structured critical review of the literature, Leffell demonstrates the difficulty of drawing any meaningful conclusions as to the efficacy of photorejuvenation, and he points to the need for more carefully designed, scientifically sound studies to better evaluate these therapeutic light sources.
This Month in Archives of Dermatology. Arch Dermatol. 2002;138(11):1413. doi:10.1001/archderm.138.11.1413