Hamada Toshihisa, Aoyama Yumi, Shirafuji Yoshinori, Iwatsuki Keiji
Department of Dermatology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama, Japan.
Department of Dermatology, Kurashiki Medical Center, Kurashiki, Japan.
Int J Dermatol. 2017 May;56(5):540-546. doi: 10.1111/ijd.13486. Epub 2017 Feb 7.
Chronic actinic dermatitis (CAD) is a recurrent photosensitive dermatitis that occurs predominantly on sun-exposed areas with unknown etiology. In severe cases, it may present with erythroderma, which is clinicopathologically analogous to cutaneous T-cell lymphoma. Typically, inflammatory infiltrates in the skin lesions are mainly CD8 reactive T cells. However, hematologic characteristics of CAD have not been fully elucidated.
Twenty patients with CAD ranging in age from 45 to 86 years (median, 64), including 17 males and three females (M/F ratio, 5.7), were examined. All patients were phototested for UV light. In addition, seven of the 20 patients with extensive eruption were also tested for visible light. All biopsy specimens were obtained from the CAD eruptions (n = 25 lesions). Histopathologic and immunohistochemical studies were performed. Furthermore, flow cytometric analysis was performed to determine the CD4/8 ratio using peripheral blood mononuclear cells of 13 of the 20 patients.
In 11 of the 20 patients (55%), the eruption was localized to sun-exposed areas. Skin-infiltrating T cells were CD8-dominant in the CAD eruption. Three patients (15%) showed erythroderma with a reduced CD4/8 ratio (median, 0.7) of peripheral mononuclear cells. As for treatment, eight of the 20 patients (40%) required oral cyclosporine in addition to topical therapies. Subsequently, the reduced CD4/8 ratio was normalized after treatment in two of the three patients with erythroderma.
We considered that there appeared to be a relationship between the reduced CD4/8 ratio of circulating T cells (hematologic burden) and the affected area (skin burden).
慢性光化性皮炎（CAD）是一种复发性光敏性皮炎，主要发生在阳光暴露部位，病因不明。在严重病例中，可出现红皮病，其临床病理表现与皮肤T细胞淋巴瘤相似。通常，皮肤病变中的炎性浸润主要是CD8反应性T细胞。然而，CAD的血液学特征尚未完全阐明。
对20例年龄在45至86岁（中位数为64岁）的CAD患者进行了检查，其中包括17例男性和3例女性（男/女比例为5.7）。所有患者均接受了紫外线光试验。此外，20例广泛发疹的患者中有7例还接受了可见光试验。所有活检标本均取自CAD发疹部位（共25个皮损）。进行了组织病理学和免疫组织化学研究。此外，对20例患者中的13例的外周血单个核细胞进行了流式细胞术分析，以确定CD4/8比值。
20例患者中有11例（55%）发疹局限于阳光暴露部位。CAD发疹部位皮肤浸润的T细胞以CD8为主。3例患者（15%）出现红皮病，外周单个核细胞的CD4/8比值降低（中位数为0.7）。至于治疗，20例患者中有8例（40%）除局部治疗外还需要口服环孢素。随后，3例红皮病患者中有2例在治疗后CD4/8比值降低的情况恢复正常。
我们认为循环T细胞CD4/8比值降低（血液学负担）与受累面积（皮肤负担）之间似乎存在关联。
