What is a fungal culture?

A fungal culture is a procedure used to determine if fungi are present in an area of the body. Fungi are microorganisms that thrive in moist, dark places, such as shoes, damp locker rooms, or the folds of the skin. Some types of fungi are harmless, whereas others can cause infections.

A fungal culture might also be referred to as a “fungal smear.” It can be used to test various areas of the body, including:

  • blood
  • skin
  • mucosal surfaces, such as wounds or the genital region
  • nails

If your doctor suspects that you have an infection, they will perform a fungal culture on the suspected area. Common types of fungal infections include:

  • tinea infections, including tinea corporis (ringworm), tinea pedis (athlete’s foot), or tinea cruris (jock itch)
  • vaginal “yeast” infections (yeast refers to a fungus causing the infection)
  • onychomycosis (infection of the nails by a fungus)
  • thrush (infection of the oral mucosa by a certain type of fungus)

Sometimes the symptoms of a fungal infection mimic the symptoms of a bacterial or viral infection. Because the medications used to treat bacterial and viral infections aren’t effective on fungal infections, doctors might want to perform a fungal culture to be sure that an infection is caused by a fungus.

Some typical signs and symptoms of a fungal infection in the skin are itchy, red skin and scales. Symptoms of a fungal infection in the nails include thick nails that are brittle and yellow in color. Signs of a fungal infection in the mouth include white patches on the tongue, inner cheeks, and gums. During a vaginal yeast infection, vaginal discharge and itching may occur.

Most fungal infections occur on the skin, mouth, or genitals. Some infections can be more serious and occur inside the body, such as in the lungs or the blood. However, these more invasive infections are unlikely to occur in a healthy individual with a normally functioning immune system. A fungal culture can aid in identifying the type of fungus present so that the best treatment choice can be made.

During this test, a healthcare provider brushes a large cotton swab over the area where the infection is present. There is no pain with a fungal culture, and no preparation is needed.

For a throat culture, a patient is asked to open their mouth wide so that the care provider can swab the back of the throat. If a healthcare provider suspects a nail infection, clippings may be taken and sent to the lab. If they suspect a blood infection caused by a fungus, a blood culture, also called a blood sample, will be taken.

The swab is then sent to the lab for analysis.

It can sometimes take a few weeks to get the results of a fungal culture. In the meantime, treatment with medication is sometimes recommended. It is a good idea to keep an area with a possible fungal infection dry. Because fungal infections can spread, washing hands regularly is also recommended.

If the results from the culture are negative, or normal, it means there are no fungi present. If the results are positive, it means there are fungi present. A healthcare provider might order a test to identify the type of fungus that is present. This information can help your doctor determine the most effective course of treatment.

A fungal culture will help your doctor decide if there are fungi in a certain area of your body, and if so, what kind they are. Not all fungi present on your body are of the harmful, infection-causing variety. If you do have an infection, the fungal culture will help your doctor determine the best course of treatment for you.