全身性エリテマトーデス網膜症様眼底を呈した皮膚筋炎の1例

A case of dermatomyositis with retinopathy typical for systemic lupus erythematosus

　12歳男児に両眼の視力低下が突発し，ただちに受診した。4週前から微熱があり，2日前に筋生検で皮膚筋炎と診断された。矯正視力は左右とも0.1で，両眼眼底に出血斑を伴う大型の軟性白斑が多発していた。左眼黄斑部には桜実紅斑があった。眼底所見は全身性エリテマトーデス（SLE）のそれに酷似していた。ウロキナーゼによる線溶療法とステロイド薬のパルス療法は無効であった。呼吸困難などの全身状態が悪化し，初診の2週後に血漿交換療法とシクロスポリンによる免疫抑制薬投与を開始した。これにより全身状態が急速に改善し，それまでのCPK値も降下した。網膜毛細血管の閉塞は改善し，網膜血管新生はなかった。初診から9か月後の矯正視力は右1.2，左0.1であり，発症から14か月の現在再発はない。皮膚筋炎でSLEに似た網膜病変が発症し，血漿交換療法と免疫抑制薬投与が奏効した1例である。

A 12-year-old boy presented with sudden visual loss in both eyes. He had had fever since 4 weeks before. He had been diagnosed with dermatomyositis by biopsy. His corrected visual acuity was 20/200 in either eye. Both eyes showed retinal hemorrhages and cotton-wool patches with retinal vascular occlusions. Cherry-red spot was present in the left macula. The findings closely simulated retinopathy in systemic lupus erythematosus (SLE) . Systemic treatment with urokinase and pulsed corticosteroid was ineffective. Rapid deterioration of systemic condition including dyspnea necessitated plasma exchange and systemic cyclosporine 2 weeks after initially seen by us. This treatment induced prompt improvements in systemic condition and lowering of serum CPK. Retinal occlusive retinopathy also improved without retinal neovascularization. At 9 months after his initial visit, the corrected visual acuity was 20/20 right and 20/200 left. This case illustrates that dermatomyositis may manifest SLE retinopathy and that plasma exchange and immunosuppressive therapy may induce rapid improve-ments.