Slideshows Images Quizzes
font size

Valley Fever (cont.)

Medical Author:
Medical Editor:

How is valley fever (coccidioidomycosis) diagnosed?

Early in the disease, the diagnosis is difficult because the symptoms may be mild so no tests are initiated. Accurate diagnosis of coccidioidomycosis is important because there are many diseases that have similar initial symptoms and may occur in areas of the world where coccidioidomycosis occurs; for example, Andes virus (caused by a hantavirus), arbovirus encephalitis (caused by six different viruses), Argentine hemorrhagic fever (an arenavirus infection caused by Junin virus), cryptococcosis (caused by Cryptococcus neoformans, a fungal species), and others. Fortunately, a confirmative diagnostic test is easily done by microscopic examination of sputum or a tissue biopsy. The biopsy shows characteristic fungal spherules and endospores of Coccidioides immitis or Coccidioides posadasii. These fungi can also be identified after they are cultured on fungal media (growth takes about five days). Additionally, there are several serum tests and a PCR test (to detect the genetic material of the fungus) that are available. High blood levels of IgG (an immunoglobulin) that react with the fungi can help determine the extent of the disease. Skin tests can determine if the person has been exposed to the fungi, but the test is not very specific or sensitive.

Other tests help determine the extent of the disease. The most frequent test is a chest X-ray to identify abnormalities in the lungs. MRI and CT scans are used to examine brain or other organ (especially bone) involvement. Bone scans also help to determine the presence of bone involvement. Most physicians will do other routine blood tests such as a CBC (complete blood count) and ESR (erythrocyte sedimentation rate, a marker of inflammation) test.

Occasionally, the diagnosis may require obtaining samples of tissue or tissue fluid, so lumbar puncture, bronchoscopy, and surgical or needle biopsy may be done.

Medically Reviewed by a Doctor on 3/18/2016


Women's Health

Find out what women really need.

Use Pill Finder Find it Now See Interactions

Pill Identifier on RxList

  • quick, easy,
    pill identification

Find a Local Pharmacy

  • including 24 hour, pharmacies

Interaction Checker

  • Check potential drug interactions
Search the Medical Dictionary for Health Definitions & Medical Abbreviations

Health Solutions From Our Sponsors