Article in Japanese

Recurrent facial paralysis in a varicella-naïve 15-year-old boy: zoster sine herpete identified as the cause at relapse

Yotaro Kondo^1）, Kensei Gotoh^1）, Haruna Kuriyama^1）, Masanori Sugiura^1）, Koji Takemoto^1）, Naoko Nishimura^1）, Takao Ozaki^1）

Idiopathic Bell’s palsy is the most prevalent cause of facial nerve palsy in children, with a relatively rare recurrence. Here, we report a pediatric case of recurrent facial nerve palsy caused by zoster sine herpete （ZSH）, a varicella-zoster virus （VZV） reactivation without a rash. A 15-year-old boy first developed left-sided facial nerve palsy at 12 years of age and was diagnosed with Bell’s palsy. Concurrently, his paired sera were negative for anti-VZV antibodies, and serologic patterns for herpes simplex virus and Epstein–Barr virus were consistent with previous infections. After 3 years and 6 months, he was admitted with right-sided facial nerve palsy. Vesicular lesions were not observed on the auricle or in the external auditory canal, and hearing remained normal. Serum VZV-specific DNA sequence was undetectable upon admission; however, anti-VZV immunoglobulin M （IgM） was positive, and the IgG antibody titer was markedly increased （EIA ≥128）. The patient had noticed vague discomfort in the right side of his face for 2-3 weeks before the onset, indicating prodromal symptoms. Based on these findings, ZSH was suspected to cause the recurrence. He was treated with a combination of prednisolone and valaciclovir and fully recovered without sequelae. This case emphasizes the importance of considering ZSH as a differential diagnosis in recurrent facial nerve palsy.

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1）Konan Kosei Hospital, Department of Pediatrics

Key words	facial paralysis, zoster sine herpete, varicella-zoster virus, recurrence, antibody titer
Received	May 17, 2025
Accepted	October 2, 2025

37 (4)：310─316,2025