皮膚血管炎－－不同致病因之臨床分析

Clinical analysis of different causative cutaneous vasulitis

背景：皮膚血管炎在臨床常見的可能造成的原因包括藥物、物理因子、自體免疫疾病、惡性腫瘤及感染等。本研究取自北台灣大於368個皮膚血管炎的病人，比較不同的原因所致之血管炎在臨床及組織學上的表現之差異。方法：本研究回溯性的檢驗林口長庚醫院從1987年一月至2006年四月368經病理切片確認為皮膚血管炎的病人病歷，包括219個病人同時實施免疫螢光染色檢查。這些病人依其造成血管炎的原因分為四群組：感染、藥物或食物、自體免疫成惡性腫瘤及不明原因。在這些群組中分別比較年齡、性別、病患之其他系統疾病、血管炎外的其他症狀、血球計數、抗核抗體等血清試驗以及皮膚組織免疫螢光染色之發現。結果：81（22%）個病人之皮膚血管炎由感染所造成，藥物或食物引起的有51（13.9%）個病患，其他可辨別致病原因的有39（10.6%）個病患，而不明原因造成的有193（52.4%）個病患。在感染所造成的血管炎的群組表現中，統計上顯示病患年紀較大、同時有其他疾病、貧血、發燒、喉嚨痛等。貧血在感染及其他原因所致之的血管炎都可見到，但在藥物及食物所致之血管炎較少見。在免疫螢光染色檢查中，IgA和C3同時沈積在感染所致血管炎中佔了36.2%；在藥物食物所致之血管炎佔了32.1%；在其他原因所致之血管炎佔了7.1%。結論：大部份的皮膚血管炎都是不明原因引起，臨床上較特殊的表現以及皮膚組織免疫螢光染色的檢查可以幫忙鑑別可能的致病因子。

Background: Cutaneous vasculitis is common in clinical practice and leukocytoclastic vasculitis is the most common feature of histopathological findings. Possible factors triggering cutaneous vasculitis include drug exposure, physical factors, autoimmune diseases, malignancies and infections. This study was undertaken to examine our collected cases of cutaneous vasculitis by comparing the clinical features and to attempt to define different etiologies of cutaneous vasculitis. Method: This study retrospectively reviewed the medical records of patients with skin biopsy proven cutaneous vasculitis at Chang Gung Memorial Hospital from January 1987 to April 2006. A total of 368 biopsy specimens were obtained, including 219 biopsies performed using direct immunofluorescence study simultaneously. According to the underlying causes, these patients were divided into four major categories: infection, drugs or food, 'other' (autoimmune diseases and malignancies), and idiopathic. The various groups were compared to identify differences in age, gender, underlying diseases, associated symptoms, abnormal blood and serological tests, and direct immunofluorescence study. Results: Regarding the triggers, in 81 (22%) patients the trigger was infection, in 51 (13.9%) patients it was associated with drugs or food, 'other' identifiable causes accounted for 39 (10.6%) patients and in the remaining 193 (52.4%) patients the trigger was not identified. Old age, underlying diseases, anemia, fever and sore throat were the most significant associated factors for cutaneous vasculitis resulting from infection. Anemia was more frequently seen in infection and autoimmune associated cutaneous vasculitis but less often in drug induced cutaneous vasculitis. IgA plus C3 deposition occurred in over 36.2% of infection associated cutaneous vasculitis compared to 32.1% of drugs/food and 7.1% of 'other' cutaneous vasculitis. Conclusions: The most common cause of cutaneous vasculitis was idiopathic. Clinically specific characteristics and immunopathological findings are useful for distinguishing possible causative factors.