A sample of skin, hair, fingernails, or toenails is obtained using a scalpel or other instrument. The specimen is sent to a laboratory so that it can be grown in a suitable culture medium to identify potential infectious organisms.

Purpose of the Skin, Hair, or Nail Culture

  • To determine whether an abnormality of the skin, hair, or nails is caused by a bacterial, fungal, mycobacterial, or viral infection

Who Performs It

  • A doctor

Special Concerns

  • Previous therapy with antibacterial, antifungal, or antiviral drugs may lead to false-negative results.
  • The herpes zoster virus (which causes chicken pox and shingles) is very fragile and almost never grows in a culture, in some cases leading to false-negative results.
  • Certain bacteria or fungi that are cultured may not in fact be responsible for the infection, leading to false-positive results.

Before the Skin, Hair, or Nail Culture

  • No special preparation is required.

What You Experience

  • If your skin is the site of the suspected infection, the doctor scrapes the outer layer of abnormal skin with a scalpel.
  • When the scalp is affected, the doctor gently removes diseased hairs with a forceps and also scrapes your scalp with a scalpel.
  • For nail infections, the examiner scrapes the inner surface of the nail below the tip or clips off the portion of the nail that appears abnormal.
  • You may experience some minor discomfort while the sample is being collected.
  • Sample collection usually takes only about 1 minute.

Risks and Complications

  • None

After the Skin, Hair, or Nail Culture

  • You may resume your normal activities.

Results

  • The skin, hair, or nail specimen is placed in culture media in the laboratory and is then observed for the growth of microorganisms.
  • If organisms are observed growing in culture, they are identified and classified to provide a definitive diagnosis, and appropriate therapy is begun.
  • If the test is negative but the problem persists, your doctor may test another tissue sample.

Source:

The Johns Hopkins Consumer Guide to Medical Tests

Simeon Margolis, M.D., Ph.D., Medical Editor

Updated by Remedy Health Media

Publication Review By: the Editorial Staff at Healthcommunities.com

Published: 24 Jan 2012

Last Modified: 27 Feb 2015