皮疹を伴わない眼痛を初発症状とした眼部帯状疱疹の1例

A case of herpes zoster ophthalmicus with eye pain without skin rash as an initial symptom

要約　目的：帯状疱疹は神経節に潜伏した水痘帯状疱疹ウイルスの再活性化により発症し，典型的な眼部帯状疱疹の場合は特徴的な皮疹から診断が容易なことが多い。今回，皮疹を伴わない眼窩深部痛で発症し，経過中に複視と外眼筋麻痺を発症した眼部帯状疱疹を経験したので報告する。

症例：51歳，男性。主訴は頭痛および左眼窩深部痛であった。他院に救急搬送されたが頭部CTにて頭蓋内出血は否定された。翌日近隣眼科を受診し，Tolosa-Hunt症候群疑いにてメチルプレドニゾロン点滴を2日間投与されたが，のちに症状が増悪した。発症から4日後に帝京大学ちば総合医療センター（当院）脳神経内科に転院搬送され，左三叉神経第1枝領域に皮疹を認め，眼部帯状疱疹の診断となりアシクロビル点滴を開始された。発症から6日後に当院眼科を初診したところ，左眼瞼の発赤・腫脹と疼痛のため自発開眼が困難であった。眼瞼炎，結膜炎，角膜炎を認め，アシクロビル眼軟膏を開始した。発症から7日後に開眼可能となったが，複視と外眼筋麻痺を認めた。アシクロビル点滴併用下でステロイドパルス療法を施行し，眼球運動障害はほぼ改善した。

考按：本症例では，皮疹に先行して頭痛と眼窩深部痛を発症した。眼窩深部痛においては，眼部帯状疱疹も鑑別に挙げ，皮疹の発症を注意深く観察する必要がある。眼部帯状疱疹に伴う眼球運動障害に対する標準化された治療法はないが，早期の抗ウイルス薬治療とステロイドパルス併用により症状の改善が得られた。

Abstract　Purpose：Herpes zoster is known to be caused by reactivation of the varicella zoster virus that is latent in the ganglia. Typical herpes zoster opthalmicus（HZO）can be easily diagnosed based on the characteristic skin rash. Here, we report a case of HZO that initially exhibited orbital pain without rash, followed by diplopia and external ophthalmoplegia.

Case：A 51-year-old man presented with a headache and left orbital pain. Head computed tomography showed no intracranial hemorrhage. The following day, the patient visited an ophthalmology clinic, where he was treated with methylprednisolone drip for suspected Tolosa-Hunt syndrome；however, despite treatment, his symptoms worsened. Four days after symptom onset, he was transferred to the neurology department in our hospital, where a skin rash was observed in the area of the left ophthalmic branch. The diagnosis of left HZO was established, and the patient was treated with acyclovir. The patient visited the department of ophthalmology on the sixth day after onset, during which his left eyelid was red, swollen, and painful, and he showed difficulty in opening his eye spontaneously. He had blepharitis, conjunctivitis, and keratitis；the patient was started on acyclovir eye ointment. On the seventh day after onset, he was able to open his eyes and had subjective symptoms of diplopia and external ophthalmoplegia. He was treated with pulse glucocorticoid therapy combined with acyclovir, after which external ophthalmoplegia almost improved.

Conclusion：Generally, in cases of orbital pain, ophthalmologists should consider HZO as a differential diagnosis and check the onset of rash carefully. Although there is no standard treatment for external ophthalmoplegia secondary to HZO, early combined treatment with antiviral drugs and steroid therapy may improve these symptoms.