What Is a Skin Culture?

A skin culture is used to test for germs that affect your skin, fingernails, or toenails. It can be called a mucosal culture if it involves your mucosa membranes. These are the moist linings inside certain areas of your body, such as your mouth and nose.

Your doctor will order a skin culture to look for bacteria, viruses, or fungi that are causing problems with your skin or nails. For example, you might have a:

  • rash that seems to be infected
  • open sore that isn’t healing correctly
  • fungal infection

Some conditions that may require a skin culture include:

  • impetigo, a common skin infection that’s caused by strep or staph bacteria
  • athlete’s foot
  • diabetic foot ulcers
  • herpes

Your doctor will explain the purpose of the test before taking a sample. Be sure to ask any questions at that time.

A skin culture poses no risks. Your doctor will usually collect the sample with a sterile cotton swab. If you have an infection in your fingernails or toenails, they may clip a sample of your nails. Then they’ll send the sample to a laboratory for analysis.

There may be some minor risks if your doctor decides they need to collect a sample of skin using a separate procedure, known as a skin lesion biopsy. For this test, a small sample of your skin will be surgically removed. Before your exam, Talk to your doctor about the method they will use to collect the sample and any associated risks.

You won’t need to do anything before having a skin culture. In most cases, your doctor will simply use a cotton swab to collect a sample. This requires no preparation from you.

If your doctor also needs to conduct a biopsy, they may give you some easy-to-follow instructions before your test.

A skin culture is a quick, simple process that can be done in a hospital or your doctor’s office.

If your doctor is sampling an open wound or ulcer, they will take a sterile cotton swab and gently run it over the affected area. If you have an abscess or blister, your doctor may decide to lance, or cut, it. This will allow them to gather a sample of the pus or fluid inside.

If your doctor wants a sample of your fingernails or toenails, they may simply snip off a portion of your nail. This is done in the same way that you trim your nails at home.

After your doctor has collected samples, you are free to go.

Your samples will be packaged and sent to a laboratory, where the majority of the work is done. There, technicians will run tests to learn if any bacteria, fungi, or virus may be causing your symptoms. These tests may take longer if they involve samples of nails.

After a skin culture, you can go about your normal activities immediately. Your doctor will send your samples to the laboratory for testing.

When the tests are complete, the lab will send your doctor the results. Your doctor will call you to discuss your results or schedule a follow-up appointment. Your treatment options depend upon your results, including whether your tests showed signs of bacteria, fungi, or viruses.

Usually, the test results are accurate enough to determine the specific strand of virus, fungi, or bacteria causing your symptoms. This will help your doctor choose the best course of treatment.

If you notice symptoms of a possible skin or nail infection, speak with your doctor. You may have a bacterial, viral, or fungal infection. Your doctor can use a skin culture to help determine the cause of your symptoms. This test is simple and low risk. You don’t need to take any special steps to prepare for it, and you can typically return to your daily activities as soon as it’s done.