眼瞼結膜に限局したクリプトコッカス症の1例

A case of cryptococcal blepharoconjunctivitis

要約　55歳女性が左眼の上下瞼結膜に黒い塊があるのに気づいて受診した。8年前にアレルギー性結膜炎と診断され，デキサメタゾンの点眼を続けていた。結膜結石があり，数回の結石除去術を受けていた。視力は良好で，眼底その他に異常はなかった。左眼の瞼結膜に偽膜形成があり，上の瞼結膜に1個，下の瞼結膜に9個の黒色塊があった。生検で黒色塊はクリプトコッカス症と診断した。残りの黒色塊を除去し，ステロイド薬点眼を中止させた。以後の再発はない。瞼結膜のクリプトコッカス症は稀であるが，長期の副腎皮質ステロイド薬の点眼による眼局所の免疫力低下が引き金になったと推定した。

Abstract.　A 55-year-old female presented with pigmented lesions in the palpebral conjunctiva in her left eye. She had been treated by instillation of dexamethasone under the diagnosis of allergic conjunctivitis since 8 years before. She had also received repeated removal of conjunctival concretions. Besides formation of pseudomembrane,her left eye showed a pigmented lesion in the upper palpebral conjunctiva and 9 lesions in the lower. Biopsy of the pigmented lesion led to the histopathological diagnosis of cryptococcosis. She has been doing well after removal of other pigmented lesions and discontinuation of corticosteroid. Decreased local immunity due to corticosteroid appears to have induced cryptococcosis in the palpebral conjunctiva as an unusual occurrence in this patient.