A consecutive series of 150 children (aged 2 to 18 years) who presented to an emergency department with abrupt onset of severe headache were evaluated prospectively at the Children’s Hospital of the King’s Daughters, East Virginia Medical School, Norfork. Causes of acute headache included upper respiratory tract infection with fever (57%), migraine (18%), viral meningitis (9%), posterior fossa tumor (2.6%), ventriculoperitoneal shunt malfunction (2%), epileptic seizure with postictal headache (1.3%), concussion (1.3%), intracranial hemorrhage (1.3%), and undetermined (7%). The URI was viral in 39%, sinusitis in 9%, and streptococcal in 9%. Occipital location and an inability to describe the quality of pain were symptoms significantly associated with serious underlying causes. Pain intensity was not a discriminating factor. Normal activity levels were indicative of a URI-related cause and against serious pathology. Patients with migraine, URI, post-traumatic, and postictal headache had normal neurologic exams. Patients with brain tumor or hemorrhage had obvious neurologic signs, including ataxia, hemiparesis, abnormal eye movements, and papilledema. 
COMMENT. The most common cause of abrupt onset of severe headache in children is an upper respiratory tract infection with fever, sinusitis, or migraine. These children may maintain normal activities, the headache is not occipital in location, and the neurologic exam is normal. An occipital headache associated with abnormal neurologic signs is indicative of a serious structural pathology.