A case report of zoster-induced Guillain-Barré syndrome: diagnostic challenges and potential role of pulse prednisone.

Introduction and importance: Zoster-induced Guillain-Barré syndrome (ZGBS) is a rare neurological complication of varicella-zoster virus (VZV) reactivation. Diagnosing ZGBS is challenging due to its overlapping clinical features with other forms of Guillain-Barré syndrome (GBS) and zoster myelitis. This report emphasizes the importance of early recognition and tailored treatment, particularly in resource-limited settings. Case presentation: A 45-year-old Indian male presented with a 10-day history of progressive lower limb weakness and paraesthesias. Physical examination revealed a maculovesicular rash in the left C8-T2 dermatomes, areflexia, and Grade 3 muscle strength in the lower limbs and distal upper limbs, indicating lower motor neuron involvement. Cerebrospinal fluid (CSF) analysis showed albuminocytologic dissociation, and nerve conduction studies confirmed motor axonal neuropathy, consistent with the AMAN subtype of GBS. Clinical discussion: The patient was initially treated with intravenous acyclovir for suspected herpes zoster myelitis but showed no improvement. Due to limited access to intravenous immunoglobulin (IVIG), pulse prednisone therapy was initiated. The patient required supplemental oxygen for mild respiratory distress during treatment. Prolonged prednisone therapy (11 days) resulted in significant clinical improvement, with full limb function restored within 7 days of therapy tapering and complete recovery achieved by day 18 post-treatment initiation. Conclusion: This case underscores the diagnostic complexity of ZGBS and highlights prolonged pulse prednisone therapy as a viable alternative to IVIG in resource-constrained settings. Early diagnosis and tailored management are critical for optimizing recovery in rare conditions like ZGBS.