Aspergillosis: Infection with the fungus Aspergillus, seen especially in people with a deficient immune system.

The clinical features of aspergillosis can include invasive lung infection and disseminated disease, usually with fever, cough, spitting up blood, and chest pain. Aspergillosis may mimic asthma with cough and inspiratory stridor (noise on breathing in) or sinusitis with fever, localized pain.

Aspergillosis is due most often to Aspergillus fumigatus or Aspergillus flavus and less commonly A. niger, A. terreus, or A. nidulans. These fungi frequently colonize the upper respiratory tract and are among the most common in the environment.

At elevated risk for aspergillosis are people with a blood malignancy or lymphoma, anyone who has had a transplant or is taking high-dose corticosteroids and, rarely, people with HIV infection.

Diagnosis may be difficult. It usually requires a biopsy. The advent of effective, less toxic antifungal drugs (such as itraconazole) has improved therapy. The prognosis (outlook) with aspergillosis depends on the early institution of effective antifungal drug therapy or on regaining more normal immune function.