結膜下膿瘍を伴う強膜炎を初発症状として関節リウマチと診断された1例

A case of rheumatoid arthritis diagnosed with scleritis with subconjunctival abscess as the initial symptom

要約　目的：強膜炎は種々の原因で生じるが，原因疾患が判然としないこともしばしば経験する。当初，結膜下膿瘍を伴う強膜炎であることから感染性強膜炎と考えたが，のちに関節リウマチと診断された1例を経験したので報告する。

症例：52歳，女性。既往歴として約30年前に両眼の網膜復位術を施行。以前からIgM腎症，MPO-ANCA陽性のため内科にてステロイド内服中であった。X年3月に右眼の充血，疼痛のため強膜炎と診断された。全身疾患に併発した強膜炎が疑われ，精査のため内科入院となった。眼窩蜂窩織炎疑いから抗菌薬の点滴投与が行われたが，強膜炎は徐々に悪化。全身精査では新たな病変はなく，眼局所のみの炎症と診断された。結膜下膿瘍が出現し，膿から黄色ブドウ球菌を検出した。排膿後に炎症は改善したが，バックル感染を疑い結膜切開するも，新たな排膿はなく炎症は沈静化していると判断した。退院後，X年10月になり充血および疼痛が再燃したため，バックル感染の再燃を疑いバックルを抜去した。しかし炎症は改善せず，非感染性の強膜炎を疑い，セレコキシブを処方したところ炎症は軽快した。その後，X＋1年3月になり両手の手指の腫脹，関節痛が出現。内科にて関節リウマチと診断され，現在治療中である。

結論：当初は感染性強膜炎と考えたが，一連の経過から非感染性強膜炎を併発したと考えられた。結膜下膿瘍の原因は判然としなかったが，経過からバックル感染の可能性も示唆された。

Abstract　Purpose：Scleritis can be caused by a variety of factors, and it is often the case that the causative disease is not clear. We report a case of scleritis that was initially thought to be infectious scleritis because it was accompanied by a subconjunctival abscess, but was later diagnosed as rheumatoid arthritis.

Case：A 52-year-old woman with a medical history of scleral buckle surgery in both eyes 30 years prior had been taking oral steroids for IgM nephropathy and was positive for myeloperoxidase anti-neutrophil cytoplasmic antibody. In March X, she was diagnosed with scleritis presenting with congestion and pain in the right eye. Scleritis associated with a systemic disease was suspected, and the patient was admitted to the internal medicine department for further examination. Intravenous antibiotics were administered for suspected orbital cellulitis, but the scleritis gradually worsened. Systemic examination revealed no new lesions, and the patient was diagnosed with isolated ocular inflammation. Subsequently, a subconjunctival abscess was observed and Staphylococcus aureus was detected in the pus. Drainage was performed, and the inflammation improved. A conjunctival incision was made due to the suspicion of buckle infection；however, no further pus was drained, and the inflammation was deemed to have subsided. After discharge in October of year X, congestion and pain recurred. Suspecting recurrent buckle infection, the buckle was removed；however, the inflammation persisted, raising suspicion for non-infectious scleritis. Celecoxib was administered, and the inflammation subsided. In March X＋1, she developed swelling of the fingers of both hands and joint pain, subsequently leading to a diagnosis of rheumatoid arthritis by the internal medicine department, and she is currently undergoing treatment.

Conclusion：We initially thought that the patient had infectious scleritis, but the series of events led us to believe that the patient had noninfectious scleritis as well. The cause of the subconjunctival abscess was not clear, but the course of the disease suggested the possibility of a buckle infection.