Drug-induced aseptic meningitis and other mimics

Abstract

Meningitis refers to inflammation of the cerebrospinal fluid (CSF) and the meninges that surround the brain and spinal cord. Aseptic meningitis or viral meningitis has a benign, self-limited course. Aseptic meningitis can result from noninfectious causes such as medications or systemic conditions. Drugs that have been implicated as possible causes of aseptic meningitis (drug-induced meningitis or DIAM) include nonsteroidal anti-inflammatory drugs, antibiotics, immunosuppressants, and antiepileptic drugs, although monoclonal antibodies have emerged as culprit of DIAM. Systemic lupus erythematosus (SLE) stands as the single most frequent underlying condition associated with DIAM. The pathogenic mechanisms of DIAM are not fully understood, but there is evidence to suggest that they may be diverse, perhaps different for the various types of drugs. Most of the authors invoke a hypersensitivity mechanism (especially type 1 and 3). Medication-induced aseptic meningitis must remain a diagnosis of exclusion after other more common infectious causes have been effectively excluded. Thus, a thorough history on prior drug intake is key to avoid expensive diagnostic procedures or lengthy and unnecessary treatments. In cases where bacterial meningitis is a possibility, we suggest to treat the patient with a third-generation cephalosporin, only rarely linked to DIAM and active against the most likely organisms of community-acquired meningitis. Aside from DIAM, several systemic and neurological disorders, including SLE, sarcoidosis, Behçet disease, Sjögren's syndrome, and primary angiitis of the central nervous system, may also mimic infectious meningitis; therefore, differentiating from infectious meningitis is difficult, particularly considering the similar CSF profile and clinical presentation making the etiological diagnosis and management of these patients challenging.