Department of Dermatology, University of Regensburg, Regensburg, Germany.
Am J Clin Dermatol. 2010;11(3):157-70. doi: 10.2165/11530070-000000000-00000.
Pityriasis rubra pilaris (PRP) is a rare inflammatory dermatosis of unknown etiology, and finding a successful therapy can be challenging. PRP occurs equally in men and women. In some patients, associated autoimmune diseases, infections, or malignancies are possible trigger factors. PRP shows a bimodal age distribution, peaking in the first as well as in the fifth to sixth decade. Its classification into five subgroups is based on age at onset, clinical course, morphologic features, and prognosis. More than 50% of patients are best classified as type I with adult-onset PRP. This form is also characterized by high spontaneous remission rates (80%) within 1-3 years. Clinically, the classical adult (type I) and classical juvenile (type III) forms appear to be the same except for the patient's age. Recently, the designation of a new category of PRP (type VI) has been proposed that is characterized by the presence of HIV infection with different clinical features and a poorer prognosis. Typical morphologic features of PRP are erythematosquamous salmon-colored plaques with well demarcated islands of unaffected skin. Often, keratoderma of the palms and soles is present. In patients with extensive disease, ectropion is a dreaded complication. Histology shows hyperkeratosis, alternating orthokeratosis and parakeratosis in a checkerboard pattern, and focal acantholytic dyskeratosis. Descriptions and therapeutic experiences are mainly based on case reports. Mostly, systemic retinoids, methotrexate, and other immunosuppressive agents as well as UV light therapy are applied, with varying response rates. In recent years, treatment with so-called 'biologics' is becoming more and more popular for treating recalcitrant PRP. We present a review of the clinical features, histopathologic findings, classification, differential diagnoses, and treatment of PRP.
红糠疹（PRP）是一种罕见的病因不明的炎症性皮肤病，寻找成功的治疗方法可能具有挑战性。PRP 男女发病率相等。在一些患者中，自身免疫性疾病、感染或恶性肿瘤可能是触发因素。PRP 呈双峰年龄分布，高发于第一个十年和第五个至第六个十年。它的分类基于发病年龄、临床过程、形态特征和预后，分为五个亚组。超过 50%的患者最好归类为成人发病的 PRP 型 I。这种形式也具有较高的自发缓解率（80%），在 1-3 年内。临床上，除了患者年龄外，经典成人（I 型）和经典青少年（III 型）形式似乎相同。最近，提出了 PRP 的一种新分类（VI 型），其特征是存在 HIV 感染，具有不同的临床特征和较差的预后。PRP 的典型形态特征是红斑鳞屑性鲑鱼色斑块，边界清楚的未受影响的皮肤岛。常伴有手掌和足底的角化过度。在广泛疾病的患者中，外翻是一种可怕的并发症。组织学显示角化过度，交替出现正角化和角化不良呈棋盘状，以及局灶性棘层松解性角化不良。描述和治疗经验主要基于病例报告。大多数情况下，应用全身维 A 酸类、甲氨蝶呤和其他免疫抑制剂以及紫外线光疗，反应率不一。近年来，所谓的“生物制剂”治疗难治性 PRP 越来越受欢迎。我们回顾了 PRP 的临床特征、组织病理学发现、分类、鉴别诊断和治疗。
