Meningitis, typically subacute in nature, is caused by a variety of fungal organisms in both immunocompetent and immunocompromised individuals. Fungal infections are initially acquired via inhalation of fungal spores and a subsequent pulmonary infection. At times, this initial infection is asymptomatic and self-limited, yet a dormant infection and impaired cell-mediated immunity may permit reactivation of the fungus with dissemination to the central nervous system (CNS). Patients typically present with ongoing headaches, stiff neck, low-grade fever, and lethargy for days to weeks before presentation. Other common symptoms are night sweats and cranial nerve abnormalities.
Common causes of fungal meningitis include:
Cryptococcus neoformans – Found worldwide in soil and bird excrement. Typically affects immunocompromised patients such as those with HIV, organ transplantation, or cancer.
Histoplasma capsulatum – Endemic to the Ohio and Mississippi River valleys and parts of Central and South America. Also more common in immunocompromised patients.
Coccidioides immitis – Endemic to the desert southwestern United States, northern Mexico, and Argentina. May be an indolent infection and prominently has pulmonary infections.
Candida albicans – Often occurs due to disseminated spread of infection, and most common in neonates.
Rarely, meningitis may persist for 4 weeks and is then considered chronic meningitis.
ICD10CM: G02 – Meningitis in other infectious and parasitic diseases classified elsewhere