A therapeutic strategy based on histological assessment of hyperpigmented skin lesions in Asians.

Hyperpigmentation is the most common cosmetic skin complaint in Asians, but there is no standard treatment strategy. The aim of this study was to establish a simple therapeutic strategy based on the histological features of hyperpigmented skin lesions in Asians. Fifty-nine biopsies were analysed from 49 Japanese patients with 17 types of hyperpigmented skin lesions. In 10 patients, skin samples were also taken during a topical bleaching treatment that used tretinoin and hydroquinone. These samples were evaluated after staining with haematoxylin-eosin and Fontana-Masson stains. Our experience of treating a variety of pigmented lesions with aggressive topical bleaching and lasers was reviewed. Hyperpigmented lesions were classified into seven categories based on pathological features, especially on the degree of hyperkeratosis and epidermal melanin deposits, and on the existence of melanin incontinence and the location of dermal melanocytes. Tretinoin and hydroquinone therapy was histologically effective for treating epidermal melanin deposits, but not dermal melanosis or dermal melanocytes. Based on pathological features and our extensive clinical experience with hyperpigmented skin, we propose a therapeutic strategy for treating hyperpigmented skin lesions, which may be particularly useful in Asian populations.