| Where It's Done | Who Does It | How Long It Takes | Discomfort/Pain |
| Doctor's office or clinic. | Doctor. | About 1 minute. | Minimal discomfort when sample is collected. |
| Results Ready When | Special Equipment | Risks/Complications | Average Cost |
| 5 days to 3 weeks. | Scalpel or other instrument for scraping; sometimes, forceps or nail clippers. | None. | $ |
None.
PurposeTo diagnose scaly or pustular conditions of the skin, hair loss, or nail disease suspected of being caused by fungi.
How it worksFungus sample is grown in a culture medium and then may be identified under a microscope.
PreparationNone.
Test procedureSame as for KOH preparation.
After the testYou are free to resume normal activities. The sample is sent to a commercial laboratory or cultured in a doctor's office.
Factors affecting results- Previous treatment with antifungal medications may cause false-negative results.
- Some types of fungi found under the nails may not be the cause of the disease.
If a fungus is present, it may be cultured and identified. The time required varies with the organism and may take up to a month. If no fungus appears by then, the test is considered negative. However, a single negative sample cannot rule out fungal infection because the organism may have been missed during the collection of the sample or may have failed to grow. False-negative results occur in about 10% of cases.
Advantages- It's noninvasive.
- It's more reliable than a KOH.
- Negative results do not completely rule out fungal infection.
- Results may take a long time.
- Once the fungus is identified, appropriate antifungal medication can be prescribed.
- If the test is negative but the problem persists, a second sample may be taken.
