A. nidulans and A. terreus have also been reported in pediatric infections. Outbreaks of invasive disease among immunosuppressed children may occur after they have been exposed to aerosolized conidia at construction sites near hospitals and clinics. Infection is usually acquired from inhalation of airborne spores, which colonize the upper and lower respiratory tracts.
Immunocompromised persons are at risk for hematogenous dissemination.
Cutaneous infection is also common and may follow wound contamination, intradermal inoculation, or hematogenous dissemination. Ingestion and aspiration may also produce disease. The clinical symptoms are nonspecific and include the acute onset of wheezing in the absence of pulmonary infiltrates or fever. Extrinsic alveolar alveolitis is a hypersensitivity pneumonitis that occurs in nonatopic individuals after repeated exposures to organic dust. The pathogenesis is unknown but is similar to the alveolitis caused by other immunogens and may represent an immune complex disease.