Summary

Intracranial hypertension is a rare entity in prepubertal children, and its differential diagnosis includes a number of systemic diseases, drugs, vitamin deficiencies and excesses, and hereditary conditions. Infectious aetiology is rare. The case of a 9-year-old boy with intracranial hypertension secondary to acute neuroborreliosis is described. He presented with daily pulsatile frontotemporal headache, pallor, photophobia and phonophobia. His neurological examination revealed papilledema with no nuchal rigidity. The lumbar puncture showed increased pressure (50 cm H₂O) and lymphocytic pleocytosis. Serum and cerebrospinal fluid (CSF) Borrelia burgdorferi antibodies were positive. This kind of infection is rare in Portugal but a trip to an endemic area was identified. A careful history, considering the exposure to rural areas together with the intracranial hypertension and inflammatory CSF, are important clues to the diagnosis, allowing the institution to select appropriate treatment.