Test Code KOHP KOH PREP
Methodology
Direct Microscopic Examination
Useful for determining the presence of fungus in hair, nails, or skin. Cultures are more sensitive than smears; therefore, the KOH prep may be negative when the culture is positive.
Specimen Requirements
Submit only 1 of the following specimens:
Hair
Container/Tube: Sterile container(s)
Specimen Volume: 10 to 12 hairs
Collection Instructions:
1. Use a Wood’s lamp during collection, if possible (some
infected hairs exhibit fluorescence).
2. Use sterile forceps to pluck 10 to 12 hairs which are broken off
or appear diseased.
3. If diseased hair stubs are not apparent, use sterile scalpel to
scrape edges of a scalp lesion as follows:
A. Cleanse lesion with 70% isopropyl alcohol.
B. Scrape from outer periphery or border of lesion or involved
area.
4. Place specimen in sterile container.
5. Label container with patient’s legal name, date and actual
time of collection, and type of specimen.
Note: Specimen source is required.
Nails
Container/Tube: Sterile container(s)
Specimen Volume: Generous portion of affected nail
and scraping of excess keratin
Collection Instructions:
1. Remove nail polish.
2. Cleanse with 70% isopropyl alcohol.
3. Clip a generous portion of affected nail and obtain scrapings of excess keratin produced beneath nail.
4. Place specimen in sterile container.
5. Label container with patient’s legal name, date and actual
time of collection, and type of specimen.
Note: Specimen source is required.
Skin
Container/Tube: Sterile container(s)
Specimen Volume: Entire specimen
Collection Instructions:
1. Cleanse lesion with 70% isopropyl alcohol.
2. Scrape from outer periphery or border of lesion or involved
area.
3. Place specimen in sterile container.
4. Label container with patient’s legal name, date and actual time of collection, and type of specimen.
Note: Specimen source is required.
Day(s) Test Set Up
Monday through Sunday
Reference Values
No fungal elements seen
Note: Cultures are more sensitive than smears; therefore, the KOH prep may be negative when the culture is positive.
Performing Laboratory
Logan Health Medical Center Laboratory
Test Classification and CPT Coding
87220
Specimen Transport Temperature
Ambient