Cerebrospinal fluid eosinophilia in a child with neuroborreliosis.

Cerebrospinal fluid eosinophilia is rare and usually associated with eosinophilic meningitis caused by helminthic infections. It is also observed in bacterial or fungal meningitis (syphilis, tuberculosis, coccidioidomycosis), in patients with malignancies, ventriculoperitonial shunts, hypereosinophilic syndrome or allergy to some medications. Here we present a case of an 8-year-old boy admitted with fever and clinical signs of meningitis. Cerebrospinal fluid (CSF) analysis showed marked eosinophilia. Basing on further serological CSF testing the diagnosis of borreliosis was established. Cerebrospinal fluid eosinophilia in Borrelia burgdorferi infection has never been reported before.