Sign in →

Test Code M36 KOH Preparation

Important Note

For ectoparasites such as mites (scabies), lice and ticks see Arthropod Exam.

Additional Codes


PowerChart: KOH Prep

MA Cerner: KOH.

Specimen Requirement

Skin scrapings are required.

Additional Specimen Collection Information

Collect specimen using a sterile scraper [tongue depressor, scalpel or tweezers]. Sponge the infected area with 70% alcohol and allow to dry. Scrape the active [leading] edge of the lesion or top of the vesicle, with the sterile scraper, into a sterile container. Label the specimen appropriately [including source, date and time of collection]. Transport the specimen to the laboratory immediately after collection.

Useful For

Detection of fungi elements in skin scrapings.


Performed Monday through Sunday, allow 24 hours turn-around time after the specimen is received in Microbiology.

CPT Code Information

87220 Identification of Organism from Primary Source and Sensitivity Studies; Tissue examination by KOH slide of samples from skin, hair, or nails for fungi or ectoparasite ova or mites (eg, scabies)

LOINC Code Information

55303-2 Fungus [Presence] In Skin By KOH Preparation

Test Method

Wet Prep with Addition of Potassium Hydroxide (KOH)

Reference Values

Negative for Fungal Elements

(Presence or absence of fungal elements is reported.)