Acute flaccid myelitis temporally associated with rhinovirus infection: just a coincidence?

We report the case of a 3.6-year-old male child who developed progressive hyposthenia of the left lower limb. Symptoms were preceded by rhinitis, malaise, and fever. Brain and spinal magnetic resonance imaging revealed diffuse signal abnormalities compatible with a subacute myeloencephalitis. A diagnostic lumbar puncture was performed and followed by an empirical therapy including Acyclovir, Ceftriaxone, and Clarithromycin. The cerebrospinal fluid analysis revealed clear fluid, glucose, proteins, albumin within the reference range, and 144 leukocytes/mm³. Oligoclonal bands were absent and a search for viruses was negative. Wide microbiological surveillance was performed on surface swabs, blood, urine, and stool. Both nasal and pharyngeal swabs were positive for PicoRNAvirus: sequencing identified Rhinovirus A44. This virus has been detected in association with acute flaccid paralysis in only a few patients worldwide, whereas in the great majority of patients with acute flaccid paralysis other Enterovirus species were identified. The most appropriate therapeutic approach towards acute flaccid paralysis is still a matter of debate in the scientific community, with no current definitivere commendations available. With a combined immunosuppressive and anti-inflammatory therapy including intravenous immunoglobulins, intravenous Methylprednisolone, oral Prednisone, and oral Ibuprofen, we experienced a positive outcome both from the clinical point of view and from three-month follow-up imaging studies. Given the rarity and the complexity of this condition, additional studies are needed to better define the potential role of Rhinovirus A44 in the pathogenesis of the disease and the efficacy of any therapeutic measure in the management of acute flaccid paralysis.