Last updated on: November 20th, 2023

Hi there!

You’re looking at a short reference article from Explain Medicine (one of four distinct learning formats available in Clinical Odyssey). Try it out, and have fun improving your clinical skills.




Aspergillosis refers to a variety of illnesses caused by the fungal species of Aspergillus (most commonly A. fumigatus, A. flavus, A. niger, and A. terreus). Lung, skin, and central nervous system are the organs mainly involved. The manifestation of the disease depends on the host's immune status and the pulmonary structure since the species are ubiquitous in nature, and inhalation of infectious conidia (spores) is a frequent event.


The cells of the innate immunity (epithelial alveolar cells and macrophages) normally clear the inhaled Aspergillus conidia. These cells produce mediators that are able to recruit neutrophils and activate cellular immunity in order to kill the potentially invasive fungus forms (hyphae). The suppression of these mechanisms, including the suppression of the T cell responses, plays a determinant role in the occurrence of the disease and the type of the disease. Infection can disseminate to other organs.

Risk factors

Classic risk factors include severe and prolonged neutropenia, transplantations, receipt of high doses of glucocorticoids, hematological malignancies, chemotherapy, advanced AIDS and other conditions or use of other drugs that lead to chronically impaired cellular immune responses. Viral infections such as SARS CoV-2 and influenza are considered risk factors in the setting of respiratory failure in the ICUs, maybe due to the epithelial airway injury that facilitates Aspergillus colonization and invasion. Other risk factors include the presence of chronic lung diseases, such as chronic obstructive pulmonary disease.

Pulmonary aspergillosis

Aspergillosis most frequently affects the lungs since the respiratory tract is the main portal of entry. Typical forms are:

  1. Invasive pulmonary aspergillosis (IPA): this entity is typically associated with use of immunosuppressive therapies, corticosteroids, or coinfections in immunocompromised patients (especially hematological malignancies). It is characterized by invasion of pulmonary vasculature by the Aspergillus hyphae with subsequent lung damage.
  2. Chronic cavitary pulmonary aspergillosis (CCPA): this entity is typically found in non immunocompromised patients with prior or current lung disease (such as tuberculosis). It is defined as one or more pulmonary cavities with serological or microbiological evidence of Aspergillus spp and a history of at least 3 months of chronic pulmonary symptoms or progressive radiologic abnormalities.
  3. Aspergilloma: this entity is typically found in nonimmunocompromised patients with prior or current lung disease (such as tuberculosis). It is defined as a single pulmonary cavity containing a fungus ball with microbiological or serological evidence of Aspergillus spp and a history of minimal or no symptoms and no radiographic progression over a 3 months of observation.
  4. Allergic bronchopulmonary aspergillosis (ABPA): this entity is typically found in patients with asthma and cystic fibrosis. There are recurrent asthma exacerbations caused by a hypersensitivity reaction to the fungus. It is associated with elevated Aspergillus-specific IgE, elevated total IgE, detectable Aspergillus-specific IgG, eosinophilia and positive skin prick tests for Aspergillus.

COVID-19 associated pulmonary aspergillosis (CAPA)

CAPA is characterized by pulmonary infiltrates, preferably documented by chest CT, or cavitating infiltrate in patients with COVID-19 pneumonia needing intensive care and microbiological evidence of fungal elements in clinical specimens (bronchoalveolar lavage, sputum, serum, plasma).

Central nervous system infection

Aspergillus spp can disseminate beyond the respiratory tract to multiple different organs, including the brain. Typical patterns observed in brain imaging are cerebral abscesses or cortical and subcortical infarction. The prognosis is poor.

Cutaneous aspergillosis

Cutaneous aspergillosis may occur either from direct inoculation of spores, usually in the presence of trauma, or from contiguous extension or bloodborne spread.

Want to continue reading?

Subscribe to Clinical Odyssey today.
  • Enjoy unlimited access to 700+ learning modules.
  • Safely improve your skills, anytime and anywhere.
  • Get answers to your follow-up questions from practicing physicians.
Learn more ➜