Aseptic meningitis is an illness characterized by serous inflammation of the linings of the brain (ie, meninges), usually with an accompanying mononuclear pleocytosis. Clinical symptomatology is varied and includes predominantly headache and fever. The illness is usually mild and runs its course without treatment; however, some cases can be severe and life threatening. Aseptic meningitis syndrome is not caused by pyogenic bacteria, but can be caused by multiple conditions including infectious viral and nonviral causes and many noninfectious etiologies.