Tests and diagnosis

By Mayo Clinic Staff

Diagnosing an infection caused by aspergillus mold can be difficult. Aspergillus is common in the environment and is sometimes found in the saliva and sputum of healthy people. What's more, it's hard to distinguish aspergillus from other molds under the microscope, and symptoms of the infection are similar to those of conditions such as tuberculosis.

Your doctor is likely to use one or more of the following tests:

  • Imaging test. A chest X-ray or computerized tomography (CT) scan — a type of X-ray that produces more-detailed images than conventional X-rays do — can usually reveal a fungal mass (aspergilloma), as well as characteristic signs of invasive and allergic bronchopulmonary aspergillosis.
  • Respiratory secretion (sputum) test. In this test, a sample of your sputum is stained with a dye and checked for the presence of aspergillus filaments. The specimen is then placed in a substance that encourages the mold to grow to help confirm the diagnosis.
  • Tissue and blood tests. Diagnosing allergic bronchopulmonary aspergillosis usually requires skin and blood tests. For the skin test, a small amount of aspergillus antigen is injected into the skin of your forearm. If your blood has antibodies to the mold, you'll develop a hard, red bump at the injection site. Blood tests look for high levels of certain antibodies, indicating an allergic response.
  • Biopsy. Examining a sample of tissue from your lungs or sinuses under a microscope is usually necessary to confirm a diagnosis of invasive aspergillosis.
Apr. 29, 2011

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