Histoplasmosis
Histoplasmosis is a fungal infection caused by Histoplasma capsulatum, a mould that lives in soil enriched by bird and bat droppings. Most infections are mild and self-limiting, but in people with weakened immune systems the fungus can spread beyond the lungs and become life-threatening.
Key takeaways
- Exposure to disturbed soil around bird or bat droppings is a clue, but symptoms and scans can resemble other lung diseases.
- Mild infection may need observation only, while severe or disseminated disease requires specialist antifungal treatment.
- Immune suppression greatly increases the risk of spread beyond the lungs.
An antifungal listing cannot diagnose histoplasmosis; exposure history, antigen or tissue testing, severity and immune status guide treatment.
How is histoplasmosis recognised?
Fever, cough, chest pain and fatigue can follow heavy exposure in caves, demolition sites or bird roosts. Antigen testing, imaging, cultures or biopsy may be needed. Advanced HIV, transplantation and substantial immune-suppressing treatment raise the risk of disseminated infection.
When are antifungals used?
Itraconazole is used for selected non-severe disease and follow-on therapy, but absorption, interactions and liver effects need monitoring. Severe disease usually begins with hospital-based intravenous treatment. See antifungals for class information.
When to seek urgent care
Seek urgent care for worsening breathing difficulty, confusion, fainting, severe weakness or persistent high fever. An immunocompromised person with fever, weight loss or new respiratory symptoms needs prompt assessment.