Tissue examination by KOH slide of samples from skin, hair, or nails for fungi or ectoparasite ova or mites (eg, scabies)
CPT4 code
Name of the Procedure:
Tissue Examination by KOH Slide of Samples from Skin, Hair, or Nails (KOH Test for Fungi or Ectoparasites)
Summary
The KOH (potassium hydroxide) test is a simple procedure used to diagnose fungal infections and ectoparasite infestations, such as scabies, by examining samples from the skin, hair, or nails under a microscope.
Purpose
The procedure is aimed at identifying the presence of fungi or ectoparasite ova and mites. This helps in diagnosing conditions like dermatophytosis (ringworm) or scabies. The goal is to confirm the infection and guide appropriate treatment.
Indications
- Symptoms like persistent itching, rashes, or scaling of the skin
- Discolored or brittle nails
- Hair loss or scaling on the scalp
- Suspicion of scabies or other ectoparasite infestations
Preparation
- No special preparation is usually required.
- Patients should inform the doctor of any current medications or skin treatments.
- It is advisable to avoid applying topical ointments or creams on the area to be sampled before the procedure.
Procedure Description
- The doctor cleans the area from which a sample will be taken.
- A small scraping of skin, hair, or nail is collected using a scalpel or other tool.
- The sample is placed on a glass slide.
- Several drops of 10-20% potassium hydroxide (KOH) solution are added to the sample.
- The slide is heated gently to dissolve keratin, making fungi or ectoparasites more visible.
- The sample is examined under a microscope to identify any fungal elements or parasites.
No anesthesia or sedation is required for this procedure.
Duration
The procedure typically takes around 15-20 minutes.
Setting
This procedure is usually performed in a doctor's office or outpatient clinic.
Personnel
- Dermatologist or trained medical practitioner
- Medical assistant or nurse
Risks and Complications
- Minimal risks are associated with the procedure.
- Minor discomfort or irritation at the sample site.
- Rarely, there might be a slight risk of infection at the collection site.
Benefits
- Quick and effective diagnosis of fungal and parasitic infections.
- Immediate results can facilitate prompt treatment.
Recovery
- No significant recovery time is required.
- Patients can return to normal activities immediately after the procedure.
- Follow-up appointments may be scheduled based on the results.
Alternatives
- Fungal culture: This method takes longer, typically several days to weeks, but is highly accurate.
- Polymerase Chain Reaction (PCR): A more advanced and sensitive technique for detecting fungal DNA, not always available in all settings.
- Skin biopsy: A more invasive procedure, usually performed if initial tests are inconclusive.
Patient Experience
- The patient may feel mild discomfort during the sample collection.
- Minimal to no pain is expected.
- Most patients tolerate the procedure well with no need for pain management.