Nonpyogenic meningitis

This code represents inflammation of the meninges, the membranes surrounding the brain and spinal cord, that is not caused by bacterial infection. It typically involves a sterile inflammatory process, often viral in origin, but can also be due to fungal infections, parasitic infections, or non-infectious causes like autoimmune diseases or drug reactions. Patients present with symptoms such as headache, fever, nuchal rigidity, and photophobia.

Use this code when documentation specifies meningitis that is explicitly stated as nonpyogenic, aseptic, or viral. This diagnosis is often confirmed by cerebrospinal fluid (CSF) analysis showing pleocytosis with a predominance of lymphocytes and negative bacterial cultures. It is appropriate for cases where bacterial meningitis has been ruled out.

• Do not use this code if bacterial meningitis is suspected or confirmed; instead, refer to codes for pyogenic meningitis.
• Always review the CSF analysis results and physician's final diagnosis to confirm the nonpyogenic nature.
• If the underlying cause (e.g., specific viral agent, fungal infection) is identified, code it as a secondary diagnosis.