Aspergillosis

GENERAL PRINCIPLES

• Aspergillus species are ubiquitous environmental fungi that cause a broad spectrum of disease, usually affecting the respiratory system and sinuses.

• Pulmonary aspergillomas arise in the setting of preexisting bullous lung disease and are easily recognized by characteristic radiographic presentation and Aspergillus serology.

• Invasive aspergillosis (IA) is a serious condition associated with vascular invasion, thrombosis, and ischemic infarction of involved tissues and progressive disease after hematogenous dissemination. IA is usually seen in severely immunocompromised patients, especially allogeneic HSCT recipients.

• Allergic bronchopulmonary aspergillosis is a chronic relapsing and remitting respiratory syndrome associated with Aspergillus colonization.

DIAGNOSIS

• Diagnosis can be very difficult given the varied manifestations of IA, and a high index of suspicion should be applied to patients with prolonged severe immunosuppression.

• Radiographic findings can be highly suggestive of pulmonary IA, particularly the halocrescent sign on CT.

• Histopathology/cytology and culture examination of tissue and fluid specimens is recommended.

• Serum and bronchoalveolar lavage (BAL) galactomannan assay are accurate markers for the diagnosis

of IA and can be followed prospectively in at-risk patients (e.g., hematologic malignancy, HSCT).³⁷

TREATMENT

See Table 14-13.