Cohen Philip R
The University of Houston Health Center, University of Houston, Houston, Texas, USA.
Am J Clin Dermatol. 2009;10(5):301-12. doi: 10.2165/11310730-000000000-00000.
Sweet syndrome, pyoderma gangrenosum, and subcorneal pustular dermatosis are neutrophilic dermatoses - conditions that have an inflammatory infiltrate consisting of mature polymorphonuclear leukocytes. The neutrophils are usually located within the dermis in Sweet syndrome and pyoderma gangrenosum; however, in subcorneal pustular dermatosis, they are found in the upper layers of the epidermis. Sweet syndrome, also referred to as acute febrile neutrophilic dermatosis, is characterized by pyrexia, elevated neutrophil count, painful erythematous cutaneous lesions that have an infiltrate of mature neutrophils typically located in the upper dermis, and prompt clinical improvement following the initiation of systemic corticosteroid therapy. Classical, malignancy-associated, and drug-induced variants of Sweet syndrome exist. Pyoderma gangrenosum is characterized by painful, enlarging necrotic ulcers with bluish undermined borders surrounded by advancing zones of erythema; its clinical variants include: ulcerative or classic, pustular, bullous or atypical, vegetative, peristomal, and drug-induced. Subcorneal pustular dermatosis is an uncommon relapsing symmetric pustular eruption that involves flexural and intertriginous areas; it can be idiopathic or associated with cancer, infections, medications, and systemic diseases. Since Sweet syndrome, pyoderma gangrenosum, and subcorneal pustular dermatosis share not only the same inflammatory cell but also similar associated systemic diseases, it is not surprising that the concurrent or sequential development of these neutrophilic dermatoses has been observed in the same individual. Also, it is not unexpected that several of the effective therapeutic interventions - including systemic drugs, topical agents, and other treatment modalities - for the management of these dermatoses are the same. The treatment of choice for Sweet syndrome and idiopathic pyoderma gangrenosum is systemic corticosteroids; however, for subcorneal pustular dermatosis, dapsone is the drug of choice. Yet, tumor necrosis factor-alpha antagonists are becoming the preferred choice when pyoderma gangrenosum is accompanied by inflammatory bowel disease or rheumatoid arthritis. Potassium iodide and colchicine are alternative first-line therapies for Sweet syndrome and indomethacin (indometacin), clofazimine, cyclosporine (ciclosporin), and dapsone are second-line treatments. Cyclosporine is effective in the acute management of pyoderma gangrenosum; however, when tapering the drug, additional systemic agents are necessary for maintaining the clinical response. In some patients with subcorneal pustular dermatosis, systemic corticosteroids may be effective; yet, systemic retinoids (such as etretinate and acitretin) have effectively been used for treating this neutrophilic dermatosis - either as monotherapy or in combination with dapsone or as a component of phototherapy with psoralen and UVA radiation. Topical agents can have an adjuvant role in the management of these neutrophilic dermatoses; however, high-potency topical corticosteroids may successfully treat localized manifestations of Sweet syndrome, pyoderma gangrenosum, and subcorneal pustular dermatosis. Intralesional corticosteroid therapy for patients with Sweet syndrome and pyoderma gangrenosum, hyperbaric oxygen and plasmapheresis for patients with pyoderma grangrenosum, and phototherapy for patients with subcorneal pustular dermatosis are other modalities that have been used effectively for treating individuals with these neutrophilic dermatoses.
Sweet综合征、坏疽性脓皮病和角层下脓疱性皮肤病均为嗜中性皮病，即具有由成熟多形核白细胞组成的炎性浸润的病症。在Sweet综合征和坏疽性脓皮病中，嗜中性粒细胞通常位于真皮内；然而，在角层下脓疱性皮肤病中，它们见于表皮上层。Sweet综合征，也称为急性发热性嗜中性皮病，其特征为发热、嗜中性粒细胞计数升高、疼痛性红斑性皮肤损害，有成熟嗜中性粒细胞浸润，通常位于真皮上层，且在开始全身用皮质类固醇治疗后临床迅速改善。Sweet综合征存在经典型、与恶性肿瘤相关型和药物诱发型。坏疽性脓皮病的特征为疼痛性、不断扩大的坏死性溃疡，边界呈青紫色且有潜行，周围有进行性红斑区；其临床变型包括：溃疡性或经典型、脓疱型、大疱型或非典型型、增殖型、造口周围型和药物诱发型。角层下脓疱性皮肤病是一种罕见的复发性对称性脓疱性皮疹，累及屈侧和摩擦部位；可为特发性，或与癌症、感染、药物及全身性疾病相关。由于Sweet综合征、坏疽性脓皮病和角层下脓疱性皮肤病不仅共享相同的炎性细胞，还伴有相似的全身性疾病，因此在同一个体中观察到这些嗜中性皮病同时或相继发生并不奇怪。同样，用于治疗这些皮肤病的几种有效治疗干预措施（包括全身性药物、局部用药及其他治疗方式）相同也不足为奇。Sweet综合征和特发性坏疽性脓皮病的首选治疗方法是全身用皮质类固醇；然而，对角层下脓疱性皮肤病而言，氨苯砜是首选药物。然而，当坏疽性脓皮病伴有炎症性肠病或类风湿关节炎时，肿瘤坏死因子-α拮抗剂正成为首选。碘化钾和秋水仙碱是Sweet综合征的替代一线疗法，吲哚美辛（消炎痛）、氯法齐明、环孢素和氨苯砜为二线治疗药物。环孢素对坏疽性脓皮病的急性处理有效；然而，在逐渐减少用药剂量时，需要额外的全身性药物来维持临床反应。在一些角层下脓疱性皮肤病患者中，全身用皮质类固醇可能有效；然而，全身性维甲酸（如依曲替酯和阿维A）已有效地用于治疗这种嗜中性皮病——可作为单一疗法，或与氨苯砜联合使用，或作为补骨脂素和紫外线A光疗的一部分。局部用药在这些嗜中性皮病的治疗中可起辅助作用；然而，高效局部用皮质类固醇可能成功治疗Sweet综合征、坏疽性脓皮病和角层下脓疱性皮肤病的局限性表现。对Sweet综合征和坏疽性脓皮病患者进行皮损内皮质类固醇治疗、对坏疽性脓皮病患者进行高压氧治疗和血浆置换，以及对角层下脓疱性皮肤病患者进行光疗，都是已有效用于治疗这些嗜中性皮病患者的其他方式。
