Fungal Infections

Medically Reviewed By William C. Lloyd III, MD, FACS

What are fungal infections?

Fungal infections are infections caused by a fungus, a type of microorganism. Two common causes of fungal infections are a fungus called tinea and yeast infections caused by the fungus Candida albicans.

Some very common types of fungal infections caused by tinea include:

  • Athlete’s foot

  • Jock itch

  • Ringworm

Common yeast infections, also called candida and candidiasis, can infect other areas of the body including:

  • Esophagus

  • Digestive tract (gastroenteritis)

  • Lungs

  • Mouth (oral thrush)

  • Urinary tract

  • Vagina (vaginal yeast infection, vaginal thrush)

In most cases, fungal infections are treatable in generally healthy people. However, these infections are more likely to occur and can be more difficult to treat in people with weakened immune systems due to such conditions as HIV/AIDS, diabetes, organ transplantation, or taking steroid medications or chemotherapy. In these cases, complications of fungal infections may become life threatening. Recurring fungal infections can also be a symptom of a serious, undiagnosed, underlying disease, such as HIV/AIDS or diabetes. Seek prompt medical care for recurring fungal infections including vaginal yeast infections.

What are the symptoms of fungal infections?

Symptoms of fungal infections differ depending on the type and severity of the infection, the area of the body affected, and individual factors.

Symptoms of athlete’s foot

Symptoms of athlete’s foot include:

  • Itching of the feet

  • Scaling and flaking of the skin of the feet

Symptoms of jock itch

Symptoms of jock itch most often occur in men and include:

  • Itching of the groin area

  • Red, scaly rash in the groin area

Symotoms of ringworm

Symptoms of ringworm include:

  • Red, itchy area on the scalp, often in the shape of a ring

  • Hair loss in the affected area

Symptoms of fungal infections that affect the mouth

Symptoms of fungal infections that affect the mouth (oral thrush) include:

  • Lesions or sores that are raised, are yellow-white in color, and appear in patches in the mouth or throat and/or on the tongue

  • Sore, bleeding gums

  • Patches or lesions that become sore, raw and painful, making it difficult to eat or swallow

Symptoms of fungal infections that affect the vagina

Symptoms of fungal infections that affect the vagina (vaginal thrush) include:

Symptoms of fungal infections that affect the digestive tract

Symptoms of fungal infections that affect the digestive tract (fungal gastroenteritis) include:

Recurrent fungal infections can be a symptom of a more serious condition, such as HIV/AIDS or diabetes. It is important to seek prompt medical care for repeated fungal infections, such as repeated vaginal yeast infections or oral thrush.

What causes fungal infections?

Different types of fungus cause a variety of fungal infections:

  • Athlete’s foot, jock itch, and ringworm are caused by a fungus called tinea.

  • Most yeast infections, such as vaginal thrush, oral thrush, and fungal gastroenteritis, are caused by a fungus called Candida albicans. Fungus can also cause fungal infections of the lungs due to inhaled fungal spores.

Certain factors or conditions can result in an overgrowth of fungus in the body. These include:

  • Taking antibiotics. Antibiotics can kill off “healthy” bacteria in the body, as well as bacteria that cause disease. When antibiotics kill the healthy bacteria, the normal balance of microorganisms in the mouth, vagina, intestines, and other places in the body is altered, resulting in an overgrowth of Candida albicans or other fungi.

  • Having a weakened immune system due to certain conditions, such as HIV/AIDS or taking steroid medications or chemotherapy

  • Having a weakened immune system due to certain conditions, such as HIV/AIDS, organ transplant recipient, or taking steroid medications or chemotherapy

  • Having high blood sugar due to diabetes, which provides food for Candida albicans and encourages its overgrowth

Fungal infections can also be passed from a pregnant woman to her infant during vaginal delivery or breastfeeding.

What are the risk factors for fungal infections?

A number of factors increase the risk of developing fungal infections. Not all people with risk factors will develop fungal infections. These factors include:

  • Being very young or very old

  • Douching or using feminine deodorants or scented tampons

  • Exposure to contaminated surfaces especially shower facilities, swimming pools, hot tubs/spas.

  • Having diabetes

  • Having a weakened immune system due to such conditions as HIV/AIDS, or taking steroid medications or chemotherapy

  • Organ transplant recipient

  • Poor personal hygiene

  • Taking strong antibiotics, especially for long periods of time

  • Wearing tight-fitting underwear, thongs, jeans, or other pants if you are a female

Reducing your risk of fungal infections

You can lower your risk of developing or transmitting fungal infections by:

  • Avoiding douching

  • Changing tampons frequently

  • Cleansing the genitals daily with mild soap and water

  • Eating a well-balanced, healthy diet

  • Following your treatment plan for conditions, such as diabetes and HIV/AIDS

  • Getting early and regular prenatal care when pregnant

  • Not using feminine deodorants or scented or deodorant tampons

  • Not wearing tight-fitting underwear, thongs, jeans, or other pants if you are a female

  • Nursing women who have nipple discharge or pain should notify their provider so they can be examined for fungal infections of the nipples, which could be transmitted to the mouth of a nursing infant.

  • Regular application of medicated foot powder

  • Seeking regular routine medical care

  • Taking antibiotics only when prescribed by your health care professional and finishing the medication exactly as directed

  • Thorough drying of body surfaces after washing

  • Wearing cotton underwear

How are fungal infections treated?

Treatment of fungal infections begins with seeking regular medical care throughout your life. Regular medical care allows your health care professional to assess your risks of developing fungal infections and promptly order diagnostic testing for fungal infections and underlying conditions as needed. These measures greatly increase the chances of diagnosing and treating underlying causes of fungal infections in their earliest stages.

Fungal infection treatment includes:

  • Antiseptic mouth washes for oral thrush

  • Diagnosing and treating any underlying diseases, such as HIV/AIDS and diabetes. Treating the high blood sugar levels of diabetes may resolve a current infection and is critical to minimizing the risk of developing recurrent fungal infections.

  • Eating yogurt or taking acidophilus supplements, which can help to correct the abnormal balance of microorganisms in the mouth and digestive tract

  • Medications, including prescription topical or oral antifungal medications such as fluconazole

In many cases, oral fungal infections (oral thrush) in infants can disappear within two weeks and may need no treatment other than watching the progress of the mouth lesions. Because oral thrush may be painful in the mouth and affect feedings, the pediatrician should still be notified if symptoms appear in an infant.

What are the possible complications of fungal infections?

Complications of fungal infections can be serious for people with weakened immune systems, such as those with HIV/AIDS or those taking steroid medications or on chemotherapy. In these cases, fungal infections can spread throughout the body, causing fungal infections in vital organs, such as the heart and the brain. This can result in critical, life-threatening complications, such as:

Seek prompt medical care if you are experiencing symptoms of fungal infections and you have diabetes or HIV/AIDS, are being treating with chemotherapy, or are taking steroid medications.

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  1. Tierney LM Jr., Saint S, Whooley MA (Eds.) Current Essentials of Medicine (4th ed.). New York: McGraw-Hill, 2011.
Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2021 Jan 10
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