紫斑のないIgA血管炎と臨床診断した4例の臨床像と画像の特徴—血管炎症候群との鑑別も含めて

Clinical Characteristics and Images of Four Clinically Diagnosed Cases of Immunoglobulin A Vasculitis without Purpura with a Differential Diagnosis of Vasculitis Syndrome

要旨●紫斑がなくIgA血管炎の診断基準を満たさないが，消化管病変の特徴からIgA血管炎と臨床診断した4例の臨床像と画像の検討を行った．全例とも高齢男性で，関節症状や腎障害はほとんどなく，重度の消化管症状がみられた．罹患部位は小腸広範囲であり，内視鏡像は通常のIgA血管炎とは異なり広い潰瘍を示し，3例で全周性帯状潰瘍と島状粘膜残存がみられた．全例でステロイドホルモン（SH）が投与され有効であった．紫斑のないIgA血管炎の存在を知らないために，SHの投与が遅れることで手術を行うことになったり，長期入院を余儀なくされる可能性がある．紫斑のないIgA血管炎の存在を周知すること，消化管病変の特徴を含めた新しい診断基準の作成が必要と考えられる．

　We investigated the clinical characteristics and images of four cases that did not satisfy the diagnostic criteria for having IgA（Immunoglobulin A）vasculitis because of the absence of purpura but were clinically diagnosed as IgA vasculitis according to the gastrointestinal lesion characteristics. All patients were elderly men, and have severe gastrointestinal symptoms but no joint symptoms or renal dysfunction. In the small intestine, the affected area was widespread and endoscopic images revealed wide ulcers, unlike IgA vasculitis with purpura. Three patients exhibited circumferential band-shaped ulcers and residual island-like mucosa. SH（steroid hormones）were effective in all cases. As majority of internal medicine physicians are unaware of the existence of IgA vasculitis without purpura, delayed SH administration may lead to surgery or long-term hospitalization. Thus, it is crucial to raise awareness regarding the existence of IgA vasculitis without purpura and develop new diagnostic criteria that encompass the characteristics of gastrointestinal lesions.