# Viral encephalitis related to adalimumab in a 16-year-old Crohn’s disease patient: case report and literature review

## TL;DR

A 16-year-old Crohn’s disease patient developed viral encephalitis after adalimumab treatment, highlighting the need for neurological monitoring in pediatric cases.

## Contribution

This is the first reported case of viral encephalitis in a pediatric Crohn’s disease patient linked to adalimumab treatment.

## Key findings

- A 16-year-old CD patient developed HHV-7-related viral encephalitis after three months of adalimumab treatment.
- Discontinuation of adalimumab and acyclovir treatment led to symptom improvement.
- Literature review found 11 adult CD cases with neurological complications from adalimumab, but no prior pediatric VE cases.

## Abstract

Tumor necrosis factor-alpha (TNF-α) inhibitors are extensively utilized in inflammatory bowel disease (IBD). Adalimumab (ADA), a TNF-α inhibitor, appears to be an effective and safe option for pediatric Crohn’s disease (CD), but the potential risk of opportunistic infection and autoimmune disease is of particular concern. We present the first pediatric case of viral encephalitis (VE) in a 16-year-old boy with CD following treatment with ADA. A 16-year-old CD patient developed symptoms such as fever, dizziness, drowsiness, and blurred vision after three months of ADA treatment. Fundoscopic examination demonstrated pronounced edema of the optic disc in both eyes. The lumbar puncture revealed a marked elevation in intracranial pressure and pathogen analysis of the cerebrospinal fluid identified an HHV-7 infection using next generation sequencing. Following discontinuation of ADA and treatment with acyclovir, the child’s symptoms largely subsided. Literature search identified 11 published CD adult patients with neurological complications related to ADA treatment, while 7 cases were diagnosed with autoimmune encephalitis and 4 with Guillain-Barré syndrome. This report presents the first pediatric CD patient with treatment of ADA, during which VE manifested. Although neurological adverse events associated with ADA are infrequent in pediatrics, vigilant monitoring for neurological symptoms, particularly for infections, remains critical.