Health Encyclopedia
Sputum smear (KOH test)
Definition
Sputum smear (KOH test) is a test for the presence of fungal microorganisms in sputum.
Alternative Names
KOH test; Fungal smearHow the Test is Performed
Obtain a sputum sample by coughing deeply and expelling the material that comes from the lungs (sputum) into a specimen container. A smear of sputum is prepared with potassium hydroxide (KOH) and examined under the microscope. If it is positive, fungal cells can be observed.
How to Prepare for the Test
There is no special preparation.
How the Test Will Feel
There is no discomfort.
Why the Test is Performed
The test may be performed when there is abnormal sputum production or when an infection of the lungs is suspected.
Normal Results
No presence of organisms is normal.
What Abnormal Results Mean
Abnormal results indicate the presence of fungus such as histoplasmosis, coccidioidomycosis, or blastomycoses. White blood cells called eosinophils may also be present.
Additional conditions under which the test may be performed:
- Acute pulmonary eosinophilia (Loeffler's syndrome)
- Coccidioidomycosis; acute (primary) pulmonary
- Coccidioidomycosis; disseminated
Risks
There are no risks.
Considerations
Not applicable.
Reviewed By: Kenneth Wener, M.D., Division of Infectious Diseases, Beth Israel Deaconess Medical Center, Boston, MA. Review provided by VeriMed Healthcare Network.
