What Causes Groin Rash and How Is It Treated?

There are many possible causes for a genital rash, ranging from infections that are easily treatable to sexually transmitted infections (STIs), allergies, and autoimmune disorders.

Some of the most common causes of genital rashes are infections:

• Jock itch, a fungal infection, or ringworm of the groin area. The rash is red, itchy, and scaly, and it may blister.
• Diaper rash, a yeast infection that affects babies because of the warm, moist environment in diapers. It’s red and scaly and may include bumps or blisters.
• Vaginal yeast infection, an infection that affects the vagina and often occurs as a result of taking antibiotics. It causes itching, redness, swelling, and white vaginal discharge.
• Molluscum contagiosum, a viral infection that affects the skin and appears as firm, isolated, round bumps. They may be itchy and inflamed.
• Balanitis, an inflammation of the foreskin or the head of the penis that’s usually caused by bacterial or fungal growth and is more likely to occur in those who have uncircumcised penises. It leads to itchiness, redness, and a discharge.

Infecting parasites are another possible cause of a genital rash:

• Pubic lice are tiny insects. They lay eggs in the genital area and are most often spread from person to person through sexual contact. An infestation of pubic lice causes itchiness and sometimes sores.
• Body lice are different from pubic lice and are larger. They live in clothing and on the skin, and feed on blood. They cause an itchy rash on the skin.
• Scabies is an itchy skin rash that’s caused by very small mites. They burrow into the skin and cause intense itching, especially at night.

Allergies and autoimmune disorders are other possible reasons for a genital rash:

• Contact dermatitis is a common type of rash caused when skin comes into contact with an allergen or with an irritant such as a harsh chemical substance. Latex is an allergen that may produce a rash in the genital area because it’s commonly used in condoms.
• Psoriasis is a common skin condition. The cause is unknown, but doctors suspect it’s an autoimmune disorder. It can produce a pinkish, scaly, itchy rash anywhere on the body. Psoriasis may also produce sores in the penis area.
• Lichen planus is less common but also produces itchy skin rashes. Doctors are unsure of the exact cause, but it’s thought to be due to an allergen or autoimmune disorder. In the genital area, lichen planus can produce sores.

STIs are another possible cause of genital rashes and can include:

• Genital herpes, a virus that can produce painful, blister-like sores in the genital area.
• Genital warts, caused by the human papillomavirus (HPV). They’re small and flesh-colored and may be itchy.
• Syphilis, a bacterial infection that’s spread through sexual contact. It produces a rash that can be anywhere on the body. The rash isn’t necessarily itchy.

Before treating a genital rash, a doctor first needs to determine its cause.

You can connect to a primary care doctor in your area using the Healthline FindCare tool.

The diagnosis process can involve some or all of the following:

A physical examination

The doctor will look at the features of the rash, including any lesions or warts. Let them know about any unusual redness or discharge.

They’ll also examine other areas of the skin that may be affected. For example, they may study the webs of your fingers to look for scabies.

Swab testing

Doctors may swab vaginal discharge and any discharge present around the penis, along with lesions.

Skin scraping or biopsies

The doctor may order a skin scrape or biopsy, where they scrape or remove part of a wart, part of a lesion, or skin cells.

The tissue from the scrape or biopsy is examined under a microscope. The findings can potentially be used to diagnose conditions such as psoriasis, scabies, and fungal infections.

Blood work

Some causes of genital rashes, such as herpes and syphilis, may be detected through blood work.

There are home diagnostic tests you can use to test for STIs, though they may not be as reliable as tests run by a doctor. If you do use a home diagnostic test and get a positive result, have a doctor double-check the results and get treated as soon as possible.

The treatment needed for a genital rash depends on the underlying cause.

Regardless of the cause, however, the itchiness of a rash can be treated with over-the-counter (OTC) creams such as hydrocortisone.

A doctor may also prescribe you a cream to reduce the symptoms while treating the underlying condition.

Some skin infections will heal without treatment as long as the affected area is kept clean and dry.

Here are some other conditions and the treatments that a doctor may recommend:

Vaginal yeast infections

These can be treated with an OTC or prescription medication, such as oral antifungals.

Syphilis

Syphilis is treated with antibiotics.

Genital warts

These warts are treated with prescription medications. A doctor can also eliminate visible warts by freezing them with liquid nitrogen or removing them surgically.

Genital herpes

Genital herpes can’t yet be cured, but the condition can be managed with medications.

Pubic and body lice

Lice can be eliminated with a medicated wash, which is applied directly to the site of the infection, left on for a required amount of time, and washed away.

To prevent reinfection, you should wash clothing and bedding in hot water.

Scabies

Scabies can be treated with medicated creams or lotions prescribed by a doctor.

Allergic reactions

Eliminating the allergen will allow the rash to clear up and prevent future outbreaks.

Autoimmune disorders

While there’s no cure for autoimmune disorders, certain medications — such as those that suppress the immune system — can help control symptoms or skin conditions caused by these disorders.

Lichen planus occurring in autoimmune disorders

This can be treated with OTC antihistamines or prescription medication skin creams, corticosteroid shots, or pills.

Preventing a genital rash, particularly a reoccurring genital rash, will depend heavily on the cause of the rash itself.

To prevent rashes caused by STIs, you can:

• Always use barrier methods that protect against STIs, such as condoms and dental dams.
• Take medications to manage preexisting conditions such as herpes.

To prevent rashes from allergic reactions, you can:

• Take antihistamines when at increased risk.
• Avoid the allergens that trigger the reaction.

Maintaining a balanced diet and lifestyle will keep you in the best shape you can be in, which may boost your immune system and help it fight off any infections that could cause genital rashes.

If you have a specific concern, consult a doctor.

For most people with rashes, the outlook is very good.

In most cases, the underlying cause can be treated and the rash will clear up. With the right care, parasites and infections that aren’t STIs can be cured and prevented with good hygiene.

Conditions that have no cure, such as genital herpes or autoimmune disorders, can be successfully managed with the right medications.

Syphilis, if caught early, can be cured easily with penicillin. If it’s found later, additional courses of antibiotics may be needed.