What Is Candidiasis?

Candidiasis, or yeast infection, is an infection caused by a fungus called candida, which naturally occurs in small amounts on the skin, plus the mucosal surfaces inside the mouth, respiratory tract, intestines, and vagina.

The most common of the candida species is Candida albicans (KAN-did-uh AL-bi-kanz), also called C. albicans, but many species exist, and you may have several in and on your body right now. Candida grows best in places that are warm and moist.

Infections involving C. albicans are extremely common and are usually easy to diagnose and treat. However, some infections and strains pose serious risks to your health.

Types and Symptoms of Candidiasis

Candidiasis has different names depending on what part of the body is infected, including:

• On the genitals: vaginal candidiasis or vaginal yeast infection; candidal balanitis or male yeast infection
• In the mouth: thrush or oropharyngeal candidiasis
• In the diaper region: yeast diaper rash
• On the skin: cutaneous candidiasis
• In the fingernails/toenails: candidal paronychia
• In the blood or organs: invasive candidiasis

Vaginal or Male Yeast Infection

Candida, and especially C. albicans, overgrowth in the vagina is commonly called a vaginal yeast infection, vaginal candidiasis, or vaginitis.

Approximately 30% to 50% of women experience a yeast infection at some point during their lives, and it's more common during pregnancy. Some women find that yeast infections occur shortly after they've taken a course of antibiotics. Symptoms include:

• Vaginal itching
• Pain
• Redness
• A white, clumpy discharge

It's less common for men to have a genital yeast infection, but anyone can get them. It's often asymptomatic. When symptoms do occur, the most common one is inflammation of the tip of the penis. Some men also experience:

• Irritation
• Itchiness
• Small, rash-like bumps
• A white, clumpy, discharge that smells bad
• White, shiny patches at the top of the penis
• Pain
• Painful urination
• Sores or cracking of the foreskin

Thrush

Occurring in the mouth, throat, or esophagus, thrush is most common in babies, people with diabetes, and those who test positive for HIV.

Symptoms of thrush include:

• White patches on the tongue, roof of the mouth, and inside the cheeks
• Redness inside the mouth
• Soreness or cotton-like feeling
• Pain while eating and/or swallowing
• Cracks in the corners of the mouth

When a breastfeeding baby has thrush, the mother may experience cracked and painful nipples.

Yeast Diaper Rash

A baby may develop a yeast diaper rash alone or along with thrush. Symptoms include:

• Bold red rash with a slight, raised border
• Smaller red patches that blend with larger ones
• Blisters, ulcers, or pus-filled sores
• Red or scaly areas on the genitalia

A yeast diaper rash will appear only under the diaper and won't respond to most diaper rash treatments. If you use a treatment for two days and the rash doesn't improve, that's a sign it could be candidiasis.

Cutaneous Candidiasis

Candidiasis on the skin tends to occur most often in warm, moist areas such as the groin, armpits, anus, and under the breasts. It causes a rash characterized by:

• Red lesions, usually lined by small red pustules
• Itchy patches
• Scaly patches on the scalp, which may cause hair loss

Fingernails/Toenails

Nail infections often occur in people whose hands or feet are regularly exposed to water. A manicure or pedicure performed with contaminated tools is also a common cause.

Symptoms of candidal paryonchia include painful redness and swelling of the skin around the nail, which may, in advanced cases, include pus. The skin may look baggy. In severe cases, the nail itself may become discolored.

Invasive Candidiasis

A more serious form of candida infection in the internal organs, invasive candidiasis is less common and tends to occur in people who are already very sick, such as those who have had an organ transplant or are in the intensive care unit.

This form of candidiasis can be fatal. It most often strikes the:

• Blood (also called candidemia)
• Heart
• Brain
• Eyes
• Bones

The most common symptoms include fever and chills that don't respond to antibiotics. Other symptoms vary depending on the part(s) of the body infected.

Causes

Candida doesn't cause disease unless some kind of circumstance allows the fungus to multiply. For example, candida could overgrow after you take a course of antibiotics for a bacterial infection (such as for a urinary tract infection or pneumonia), or because the immune system is suppressed due to disease, or as a side effect of some medications.

Other potential causes of candidiasis include:

• Diabetes, as sugar in the blood feeds candida
• Poor hygiene
• Tight-fitting underwear or wet clothing
• Being overweight
• A hot, humid environment
• Skin products that irritate the skin
• Being uncircumcised
• Spermicides and condoms with lubricants
• Cancer treatment
• Sexual activity
• Perfumed products used in the vaginal area
• Douching
• Very hot baths or hot tubs

Diagnosis

Diagnosis of yeast infections varies by location but some commonalities exist.

Typically, for any form other than invasive candidiasis, a healthcare provider will perform a physical examination of the infected area and possibly take a swab or scraping that's sent to a lab and examined under a microscope. Candida is easy to identify this way.

A home test is available for vaginal yeast infections, but they measure vaginal pH and aren't specific for candida, so the results are less reliable than the test your healthcare provider performs.

For invasive candidiasis, a blood sample is sent to a lab and cultured to see if the fungus will grow.

Your healthcare provider may also order additional tests to see if you developed candidiasis as the result of an underlying disease, such as diabetes.

Treatment

Treatment of most forms of candidiasis usually involves over-the-counter (OTC) or prescription antifungal ointments or suppositories. The same medications are used regardless of the location of the infection, though the strength and method of application may vary. Medications include:

• Lotrimin, Mycelex (clotrimazole)
• Micatin (miconazole)
• Nystatin (mycostatin)
• Monistat (tioconazole)

Keeping infected skin clean and dry can also help clear it up.

Systemic Medications

For persistent or serious yeast infections, healthcare providers may prescribe a systemic antifungal medication in pill form. Especially if you have a history of yeast infections, your healthcare provider may recommend these drugs as a preventive measure whenever you take antibiotics. They're usually given in two doses taken several days apart. These drugs include:

• Diflucan (fluconazole)
• AmBisome, Amphotec (amphotericin B)
• Nyamyc, Pedi-Dri, Nystop (nystatin)

Nystatin is a common choice for candidiasis associated with HIV.

While those oral drugs are sometimes used to treat invasive candidiasis, intravenous antifungals are a more common choice. They include:

• Cancidas (caspofungin)
• Mycamine (micafungin)
• Eraxis/Ecalta (anidulafungin)

These medications may be given for several weeks to ensure that all of the fungi are out of your system. Long-term antifungal therapy may be needed to treat chronic candidiasis, as well. 

Frequently Asked Questions

Why do my yeast infections keep coming back?

A frequent reason is that the initial infection wasn’t completely cleared up. You might need a different prescription medication and extended treatment of up to six months. A second common reason: You’re being re-exposed via a nursing baby with thrush or a sexual partner who has an untreated infection.

How long before I can have sex after having a yeast infection?

Wait until your symptoms are completely gone before having sex. Depending on the product you use and the infection, it may take 14 days to complete treatment, and after that, you should see symptoms go away.

Is candidiasis considered a sexually transmitted disease?

No. A yeast infection (candidiasis) can be transmitted during sexual intercourse from one partner to another. However, you can also develop the infection without having sex, so it isn’t considered an STD.

A Word From Verywell

If you believe you have some form of candidiasis, it's important for you to see a healthcare provider—especially the first time—so you can confirm the cause of your symptoms and get started on the right medication. Someone who's more familiar with symptoms may opt to simply start treatment with OTC ointments. However, any time you have recurrent, treatment-resistant, or severe symptoms, you should seek medical help.