Skin rejuvenating effects of chemical peeling: a study in photoaged hairless mice.

BACKGROUND: Chemical peeling is a dermatologic treatment for skin aging. However, the mechanism by which the chemical peel achieves its results is not clear. We investigated the effects of chemical peeling and the mechanism of wrinkle reduction in photoaged hairless mice skin. METHODS: After inducing photoaged skin in hairless mice by repetitive ultraviolet-B irradiation applied over 14 weeks, we applied trichloroacetic acid (TCA) 30%, TCA 50%, and phenol on areas of the same size on the backs of the mice. Punch biopsies were obtained 7, 14, 28, and 60 days after the procedure for histologic and immunohistochemical analyses. RESULTS: Histologic examination showed an increase in dermal thickness, collagen fibers, and elastic fibers in the dermis of intervention groups compared with control groups. These increases were maintained significantly for 60 days. CONCLUSIONS: This study demonstrates that chemical peeling reduces wrinkles and regenerates skin by increasing dermal thickness and the amount of collagen and elastic fibers in photoaged skin.

A Case of Disseminated Nocardiosis Secondary to the Skin Nodules in an Elderly Woman.

Nocardiosis refers to a locally invasive or disseminated infection associated with the Nocardia species. Most infections enter through the respiratory tract and then disseminate systemically. Rarely can a primary nocardial infection of the skin spread to contiguous structures or disseminate to other internal organs in immunocompromised hosts. We describe a 70-year-old woman who suffered from recurrent nodular skin lesions on her right hand, forearm and elbow following inoculation of a traumatic injury. Analysis of the purulent exudates obtained from the nodule revealed Nocardia species. After 20 days, a chest X-ray showed newly developed multiple nodules in both lungs. The diagnosis of systemic nocardiosis was established, and we treated this case with trimethoprim-sulfamethoxazole.