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Test Code Billings Clinic: 6764 Potassium Hydroxide Preparation, Hair

Performing Laboratory

Billings Clinic Laboratory

Methodology

Potassium hydroxide (KOH) preparation is used to determine the presence of fungus in various sites such as skin, nails, hair, sputum, etc.

Specimen Requirements

1. Using forceps, pluck at least 10 to 12 affected hairs that fluoresce under a Wood’s lamp or non-fluorescent hairs which are broken off and appear diseased. If diseased hairs are not apparent, scrape edges of scalp lesion.

2. Place into a screw-capped, sterile container.

3. Label container with patient’s name (first and last), date and actual time of collection, and type of specimen.

4. Maintain sterility and forward promptly.
Note:  Specimen source is required on request form for processing.

Reference Values

No fungal elements seen
Note:  Cultures are more sensitive than smears; therefore, KOH preparation may be negative when culture is positive.

Day(s) Test Set Up

Monday through Sunday

Test Classification and CPT Coding

87220