Harris John E, Seykora John T, Lee Robert A
Department of Dermatology, Hospital of the University of Pennsylvania, 3600 Spruce St, 2 Maloney Bldg, Philadelphia, PA 19104, USA.
Arch Dermatol. 2010 Apr;146(4):422-5. doi: 10.1001/archdermatol.2010.42.
Immune responses are largely regulated by cytokines that are secreted by activated T cells. Interactions among these cells are complex, and the interaction between 2 responses may alter the effect of either response alone. It has been established that contact sensitization-induced inflammation can reverse hair loss due to alopecia areata. In parallel, the Renbök phenomenon demonstrates how 2 distinct autoimmune diseases--psoriasis and alopecia areata--interact to result in clinically active psoriasis suppressing alopecia areata.
We describe a patient with concurrent psoriasis and alopecia universalis with terminal hairs within plaques on his extremities, representing the only normal hair growth on his body. Adjacent biopsy specimens confirmed our clinical suspicion of plaque psoriasis with normal hair follicles and alopecia universalis with a peribulbar lymphocytic infiltrate. Our patient's psoriatic plaques cleared rapidly with narrow-band UV-B phototherapy, but hair growth at the site was maintained. His scalp alopecia responded to squaric acid dibutylester contact sensitization therapy.
This case represents a natural experiment in which 3 distinct but overlapping immune responses favored psoriasis or contact dermatitis over alopecia areata. The precise mechanism responsible for these effects remains unclear; however, based on recent reports, we speculate that cytokine cross-regulation plays a role in competition among these distinct immune responses.
免疫反应很大程度上受活化T细胞分泌的细胞因子调节。这些细胞之间的相互作用很复杂，两种反应之间的相互作用可能会改变单独一种反应的效果。已经证实，接触性致敏诱导的炎症可以逆转斑秃导致的脱发。同时，“Renbök现象”表明了两种不同的自身免疫性疾病——银屑病和斑秃——是如何相互作用，导致临床上活动性银屑病抑制斑秃的。
我们描述了一名患有银屑病和全秃的患者，其四肢斑块内有终毛，这是他身上唯一正常的头发生长部位。相邻的活检标本证实了我们临床上对斑块状银屑病伴有正常毛囊以及全秃伴有毛囊周围淋巴细胞浸润的怀疑。我们的患者通过窄谱UV-B光疗，银屑病斑块迅速消退，但该部位的头发生长得以维持。他头皮的脱发对二丁基酒石酸接触致敏疗法有反应。
该病例代表了一项自然实验，其中三种不同但相互重叠的免疫反应更倾向于银屑病或接触性皮炎而非斑秃。导致这些效应的确切机制尚不清楚；然而，根据最近的报道，我们推测细胞因子的交叉调节在这些不同免疫反应的竞争中起作用。
