Parvovirus B19-Associated Acute Motor Axonal Neuropathy in a Child: A Case Report

A bstract Guillain–Barré syndrome (GBS) is an immune-mediated acute polyradiculoneuropathy, most often triggered by infectious agents. Acute motor axonal neuropathy (AMAN) is a less common but severe variant, predominantly affecting children. Human parvovirus B19 (B19V) is rarely implicated as a trigger of GBS. We report the case of an 8-year-old boy who presented with severe back and hip pain followed by rapidly progressive, symmetrical, ascending flaccid paralysis of the lower limbs. There was no sensory involvement, cranial nerve dysfunction, or bowel or bladder disturbance. A brief febrile illness preceded the neurological symptoms. Examination revealed hypotonia, absent deep tendon reflexes in the lower limbs, and Medical Research Council grade 2/5 power, with preserved upper-limb function. Cerebrospinal fluid (CSF) analysis showed albumin–cytological dissociation. Neuroimaging was normal. Electrophysiological studies demonstrated a predominantly motor axonal polyneuropathy consistent with AMAN. Extensive infectious and autoimmune evaluation was negative except for CSF B19V DNA positivity and serum immunoglobulin M and immunoglobulin G antibodies, confirming recent B19V infection. The child was treated with intravenous immunoglobulin and supportive physiotherapy, resulting in gradual and sustained neurological recovery, with assisted ambulation by 1 month and no residual deficits at discharge. This case highlights B19V as a rare but important trigger of AMAN in children. B19V infection should be considered in the differential diagnosis of pediatric acute flaccid paralysis, particularly in atypical or unexplained cases of motor axonal neuropathy.