What Anal Yeast Infection Looks Like and How to Treat It

An anal yeast infection is caused by the overgrowth of the same fungus, called Candida, that causes vaginal yeast infections and oral thrush. The infection, also known as perianal candidiasis, commonly causes anal itching but can also look like a scaly, butterfly-shaped rash around the anus.

Anal yeast infections are more common in people with weakened immune systems. They may also happen when taking medications like steroids or antibiotics that impair the immune response or disrupt the natural balance of bacteria and yeast on the skin. Anal yeast infections are treated with topical antifungals. Those who are immunosuppressed may require both topical and oral antifungal drugs.

What Causes Anal Yeast Infections?

An anal yeast infection is caused by the overgrowth of a type of fungus (yeast) called Candida that is naturally found on the skin and in mucosal tissues of the mouth, vagina, penis, anus, and gastrointestinal tract.

Similar to vaginal yeast infections, oral yeast infections (thrush), and penile yeast infections, anal yeast infections are mainly caused by a specific species called Candida albicans.

Under normal circumstances, C. albicans is well controlled by the immune system and by "helpful" bacteria that make up the natural microbiome of the anus and other mucosal tissues. When controlled, C. albicans is not only harmless but can even aid with digestion and the absorption of nutrients.

However, when the immune system is weak or the natural biome is disrupted, C. albicans can grow out of control and establish an infection. This is especially true in hot, moist climates where fungi like C. albicans thrive.

Certain risk factors can increase the likelihood of an anal yeast infection, including:

• Stress
• Diabetes
• Pregnancy
• Obesity
• Corticosteroids (steroids)
• Birth control pills
• Antibiotics
• Chemotherapy
• Immunosuppressants
  
• Excessive sweating
• Anal douching
• Wearing tight, restrictive clothing
• Poor hygiene

Candida is not contagious. It is a microorganism already found in the body; you can neither pass nor catch an anal yeast infection.

What an Anal Yeast Infection Looks Like

Symptoms of an anal yeast infection can vary in severity. It can range from a mild infection to one that causes severe discomfort and disability, particularly in those with a compromised immune system.

Common symptoms of perianal candidiasis include:

• Constant anal itching
• Redness and irritation
• Soreness or burning
  
• Anal or rectal pain
• Bleeding (usually caused by scratching)

Perianal candidiasis can also cause a rash that you can feel with your hand and see with a hand mirror. As opposed to other types of rash, an anal yeast infection will have certain characteristic features, such as:

• Symmetrical redness (erythema) around both sides of the anus in a butterfly pattern
• Redness extending into skin folds of the anus and perineum (the space between the anus and genitals)
• Tiny bumps (papules) or pus-filled pimples (pustules) scattered around the perimeter of the rash
• Excessive moisture and stickiness around the anus
• A generally light but visible anal discharge

Anal itching (pruritis ani) is by far the most common symptom of an anal yeast infection. Studies suggest that fungal infections account for one in seven cases of anal itching.

Diagnosis

An anal yeast infection may be recognized by its appearance, but a few simple tests are commonly performed to confirm the diagnosis.

The testing would involve a swab or scraping of tissues from the anus to look for signs of fungal spores under the microscope. Before viewing, the sample would be exposed to a chemical called potassium hydroxide (KOH) that destroys all other cells but leaves fungi intact.

You might also be placed in a chair with stirrups and given a physical exam with a Wood's lamp. This device can detect fungi by causing them to glow a bluish-green when exposed to harmless ultraviolet light.

Differential Diagnosis

If in doubt as to the cause, a swab or scraping of tissue can be sent to the lab to be cultured (grown). This can help determine if Candida or some other condition is involved.

Other possible causes include:

• Tinea cruris ("jock itch"): A contagious fungal infection caused by Trichophyton rubrum and others that can spread from the groin to the anus.
• Erythrasma: A bacterial infection caused by Corynebacterium minutissimum that can cause dark discoloration and thickened patches around the perianal region
• Impetigo: An infection caused by bacteria like Staphylococcus aureus and Streptococcus pyogenes that can cause oozing and crusting blisters around the anus and buttocks
• Perianal streptococcal dermatitis: A bacterial infection caused by Streptococcus pyogenes that causes an intense, circular area of redness around the anus
• Actinomycosis: A bacterial infection commonly caused by Actinomyces israelii that leads to hardened nodules, scarring, and the formation of fistulas (abnormal tunnels) around the anus
  

Treatment

Most yeast infections in healthy people are mild and easy to treat—as long as they stick with the treatment until it is finished. Treatment in those with a compromised immune system can be more difficult.

Over-the-Counter Treatments

There are many effective antifungal ointments, creams, or suppositories that you can purchase over the counter for the treatment of mild anal yeast infections.

These include:

• Monistat (miconazole)
• Terconazole (terazol)
• Lotrimin (clotrimazole)
• Butoconazole (gynazole)
  

Most mild yeast infections will clear within three to seven days depending on the type and strength of topical medication used. Follow the manufacturer's instructions or speak with your pharmacist or provider if you are unclear on how to use the drug.

Prescription Treatments

Your provider may start you with a topical OTC antifungal that you apply to the skin. If that doesn't work, an oral antifungal may be the next step.

In such cases, a mild-to-moderate anal yeast infection can be treated with a single, 150-milligram dose of Diflucan (fluconazole). Taken by mouth with or without food, Diflucan is generally safe but may cause stomach upset and loose stools in some people.

For severe or recurring infections, you may need to use more than one drug. This may include the combination of a topical antifungal with either a three-day course of Diflucan or a stronger oral antifungal like Brexafemme (ibrexafungerp). Common side effects of Brexafemme include headache, diarrhea, nausea, stomach pain, dizziness, and vomiting.

Maintenance therapy involving the daily use of a low-dose oral antifungal may be recommended for people with recurrent yeast infections. This is especially true for immunocompromised people, such as those with advanced untreated HIV.

Alternative Treatments and Natural Remedies

Natural treatments for yeast infections are popular, although there is little clinical research to support their use. Some of these include:

• Tea tree oil: One study showed that tea tree oil could help to enhance the treatment of recurrent yeast infections when combined with an antifungal like Diflucan.
• Ozonated olive oil: One study found that ozonated olive oil (meaning oil treated with ozone gas) could be an effective topical treatment for yeast infections.
• Garlic and thyme: One study found that a topical cream containing garlic and thyme was equally effective in treating a mild yeast infection as a topical antifungal containing clotrimazole.

Before starting any alternative treatments, speak with your healthcare provider. It remains unknown how effective these treatments are or if they cause any harm.

Prevention

You can’t always prevent a yeast infection, but there are six things you can do to reduce your risk:

• Wear cotton underwear and loose, breathable clothing. Avoid tight pants and pantyhose.
• Change out of sweaty clothes or wet swimwear as soon as possible.
• Maintain an ideal body weight. Being overweight increases skin folds and body moisture.
• Avoid anal douching or harsh cleansers that can disrupt the microbiome of the anus.
• Manage chronic conditions like diabetes and HIV.
• Speak with your healthcare provider if you have recurrent anal yeast infections and are on chronic medications like prednisone. In some cases, the dose can be adjusted or the treatment changed. However, do not stop or change doses without first speaking with your provider.
  

Summary

People can get yeast infections anywhere, including the anus. When a lot of Candida fungus grows between the buttocks, the overgrowth can trigger symptoms like intense itching, burning, and redness. 

Several OTC and prescription treatments can clear up an anal yeast infection, as long as you finish the entire course of treatment. Most anal yeast infections aren’t a reason to worry if you’re generally healthy. However, if you’re getting them a lot, talk to your provider.