A positive reaction indicates there has been exposure to the microorganism. This test can be very helpful in diagnosing early infection, since the skin test can be positive 2 to 21 days after the onset of symptoms, even before serology is positive. A significant number of patients will have anergy, or will not respond to this test even when they have the disease.

There can be false-positives, in that there can be positive results when the patient has been exposed to histoplasma fungus or blastomyces fungus, but not coccidioides.