Jordaan H F, Van Niekerk D J
Department of Dermatology, University of Stellenbosch, Tygerberg, Republic of South Africa.
Am J Dermatopathol. 1991 Aug;13(4):418-24. doi: 10.1097/00000372-199108000-00015.
Exogenous ochronosis is caused by the long-term application of skin-lightening creams containing hydroquinone. This irreversible disfiguring cosmetic problem assumes epidemic proportions in South African blacks. Mild ochronosis is characterized clinically by coarsening and darkening of the skin; severe ochronosis, by coalescing, caviar-like black papules and atrophy. Histology shows ochronotic collagen fibers with eventual formation of ochronotic colloid milium. A variable cellular infiltrate, which may be granulomatous, is present. We describe two patients with severe exogenous ochronosis who developed superimposed papular lesions. Histology in both cases showed transfollicular elimination of ochronotic fibers. In one patient, gross epidermal hyperplasia, a dense lichenoid infiltrate, and partial destruction of ochronotic fibers accompanied the process of elimination (cell-rich type). In the other, concomitant epidermal hyperplasia and a cellular infiltrate were absent (cell-poor type). Further studies are needed to prove or disprove the existence of such a proposed subdivision. Transepidermal elimination in exogenous ochronosis has been mentioned in a previous report, but to our knowledge this is the first detailed documentation of this phenomenon. The clinical and histopathological spectrum of exogenous ochronosis is thus expanded.
外源性褐黄病是由长期使用含对苯二酚的美白面霜引起的。这种不可逆的毁容性美容问题在南非黑人中呈流行趋势。轻度褐黄病的临床特征为皮肤粗糙和变黑；重度褐黄病则表现为融合性、鱼子样黑色丘疹和萎缩。组织学检查显示褐黄病性胶原纤维，最终形成褐黄病性胶样粟丘疹。存在可变的细胞浸润，可能为肉芽肿性。我们描述了两名患有重度外源性褐黄病并出现叠加丘疹性病变的患者。两例组织学检查均显示经毛囊清除褐黄病性纤维。在一名患者中，表皮明显增生、致密的苔藓样浸润以及褐黄病性纤维的部分破坏伴随清除过程（富含细胞型）。在另一名患者中，未出现伴随的表皮增生和细胞浸润（细胞稀少型）。需要进一步研究以证实或反驳这种提议的细分的存在。外源性褐黄病中的经表皮清除在先前的一份报告中已有提及，但据我们所知，这是该现象的首次详细记录。外源性褐黄病的临床和组织病理学谱因此得以扩展。
