Skin or nail culture

Your health care provider may use a cotton swab or knife blade to collect a sample from an open skin rash or skin sore. A sample of skin may need to be taken. This is called a skin biopsy . Before the skin sample is removed, you will likely receive a shot (injection) of numbing medicine to prevent pain. A small sample…

There is no preparation needed for this test. If a skin or mucosal sample is needed, your provider will tell you how to prepare.

If a skin biopsy is done, you may feel a sting when the shot of numbing medicine is given. For a nail sample, the provider scrapes the affected area of the nail or clips off a piece of the nail. There is usually no pain.

This test may be done to diagnose the cause of: A bacteria or fungus infection of the skin, finger, or toenail A skin rash or sore that appears to be infected A skin ulcer that is not healing

A normal result means no disease-causing germs are seen in the culture. Some germs normally live on the skin. These are not a sign of infection and are considered a normal finding. Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk…

An abnormal result means bacteria, fungus, or virus is present. This may be a sign of infection. Common skin infections caused by bacteria include: Impetigo Diabetes foot ulcers Common skin infections caused by fungus include: Athlete's foot Nail infections Ringworm Scalp infections

Risks include slight bleeding or infection in the area where the skin sample was removed.

Dinulos JGH. Dermatologic surgical procedures. In: Dinulos JGH, ed. Habif's Clinical Dermatology: A Color Guide in Diagnosis and Therapy . 7th ed. Philadelphia, PA: Elsevier; 2021:chap 27. Iwen PC, Thompson GR, Wiederhold NP. Mycotic diseases. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management…