Meningism

Meningism is a set of symptoms similar to those of meningitis but not caused by meningitis. Whereas meningitis is inflammation of the meninges (membranes that cover the central nervous system), meningism is caused by nonmeningitic irritation of the meninges, usually associated with acute febrile illness, especially in children and adolescents. Meningism involves the triad (3-symptom syndrome) of nuchal rigidity (neck stiffness), photophobia (intolerance of bright light) and headache. It therefore requires differentiating from other CNS problems with similar symptoms, including meningitis and some types of intracranial hemorrhage. Related clinical signs include Kernig's sign and three signs all named Brudzinski's sign.

Although nosologic coding systems, such as ICD-10 and MeSH, define meningism/meningismus as meningitis-like but in fact not meningitis, many physicians use the term meningism in a loose sense clinically to refer to any meningitis-like set of symptoms before the cause is definitively known. In this sense, the word implies "suspected meningitis". The words meningeal symptoms can be used instead to avoid ambiguity, thus reserving the term meningism for its strict sense.