There are many possible causes of a rash on the inner thigh, including but not limited to chafing, eczema, and sexually transmitted infections.

Due to the range of causes of inner thigh rashes, correct diagnosis is essential for finding the right treatment and preventing a reoccurrence.

This article lists 12 common causes of a rash on the inner thigh, along with possible treatment options and preventive techniques.

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There are many possible reasons for an inner thigh rash. Both women and men are susceptible to inner thigh rashes, although the causes may vary between the sexes.

Discover 71 causes of skin rashes, with pictures.

Potential causes of rashes on the thighs include:

Atopic dermatitis

Atopic dermatitis, more commonly known as eczema, causes itchy, dry, inflamed skin. The condition is more common in children, although it can occur in people of any age.

Eczema may begin in the creases of the elbows or knees, but it often spreads to other areas of the body, including the inner thighs.

Contact dermatitis

Contact dermatitis causes a rash to flare up following skin exposure to an irritant (irritant contact dermatitis) or an allergen (allergic contact dermatitis).

Many substances can cause irritant contact dermatitis, including:

  • bleach
  • detergents
  • fragrances
  • soap

Allergic contact dermatitis is less common and results from exposure to substances such as:

Learn more about contact dermatitis triggers.

Chafing

Chafing occurs when something rubs against the skin, irritating it. The inner thighs are prone to chafing from rubbing against each other or tight-fitting clothes.

Chafing can lead to skin discoloration, pain, a burning sensation, and, in severe cases, blisters.

Chafing symptoms will begin to resolve once the irritating contact ceases.

Heat rash

Heat rash, also known as miliaria or prickly heat, occurs when the pores clog and trap the sweat in the skin. This can cause small spots of discolored skin in the affected area, in addition to itchiness and general irritation.

It appears as tiny bumps on the skin and can affect any body area, from the back and chest to the groin and inner thighs. Symptoms usually resolve once the skin cools down.

Hidradenitis suppurativa

Hidradenitis suppurative (HS) is a rare rash that presents as blackheads or pimple-like bumps under the skin, which may burst and ooze pus. It occurs where skin rubs against skin, so it is common in the inner thighs, groin, and armpits.

The cause of HS is unknown, but it is most common in people who:

Jock itch

Despite the name, anyone can get jock itch, not just athletes. It is more common in men than women because men tend to sweat more, especially around the groin.

Jock itch occurs due to an infection by the same fungus that leads to athlete’s foot. It can itch, burn, and cause a flaky and scaly rash on the genitals, inner thighs, and buttocks.

This rash is highly contagious, especially through direct contact or by sharing towels or other items.

Pityriasis rosea

Pityriasis rosea is a common rash that often appears in the spring and fall, with symptoms including small, scaly patches on the thighs, neck, upper arms, back, or chest.

Approximately 75% of all cases of pityriasis rosea begin with a “herald patch,” which is a single oval, scaly patch, followed within 2 weeks by more patches.

The cause of pityriasis rosea is unknown, but the rash usually disappears completely within a few months.

Razor burn

Razor burn may occur when shaving, especially with unclean or dull razor blades, or when using improper shaving techniques. Razor burn can develop on any part of the body that a person shaves.

Swimmer’s itch

Swimmer’s itch, medically known as cercarial dermatitis, is an allergic reaction to certain parasites that live in some lakes, ponds, and oceans.

Symptoms include tingling or burning skin, discolored pimples, and small blisters that arise within days of swimming in infected water. Most cases do not require medical attention unless symptoms persist or get worse.

Some sexually transmitted infections (STIs) may cause a rash on the inner thigh. These include:

Genital herpes

Genital herpes occurs due to infection with the herpes simplex virus type 1 or type 2. Symptoms include itchy and painful bumps or blisters on the genitals, buttocks, and inner thighs.

There is no cure for genital herpes, and many people with the virus do not have symptoms, although they can still spread the STI to others.

Secondary syphilis

Syphilis is easy to treat in its early stages, but it can lead to serious complications when left untreated.

Initial symptoms include sores around the genitals or anus. In the second stage, known as secondary syphilis, its symptoms include fever and a skin rash that may appear on any part of the body, including the inner thighs.

Chlamydia

Chlamydia is a common STI that typically causes abnormal discharge or pain during intercourse or urination.

It can also cause sores and rashes around the genital region.

A rash on the inner thigh resembles rashes in other areas of the body. Accompanying symptoms can include:

  • blisters
  • burning sensations
  • discomfort
  • itchiness
  • oozing from the lesions
  • pain
  • skin bumps
  • scaly patches

The rash may become more irritated if the thighs rub together or if someone is wearing tight clothing on the legs.

If the rash is accompanied by other symptoms, such as fever or pain, a person should contact a doctor.

The underlying cause of a rash on the inner thighs will be diagnosed based on:

  • a visual examination of the rash
  • a person’s medical history
  • any other symptoms

In some cases, a rash sample may be sent for further testing. Some people may be referred to a dermatologist (a doctor specializing in skin disorders).

The recommended treatment will depend on the cause of the rash. Not all rashes will require intervention, as they may clear up independently.

When treatment is necessary, options include:

Medications

Several medications are available to treat a rash on the inner thigh, including:

Home remedies

Depending on the type of inner thigh rash, one or more of the following home remedies may help:

To avoid getting an inner thigh rash, a person may try:

  • keeping the skin dry
  • showering with temperate, not hot, water
  • maintaining a moderate weight
  • avoiding sharing towels
  • using proper shaving techniques
  • quitting smoking, if applicable
  • using barrier methods during sex

Below are some commonly asked questions about a rash on the inner thigh.

Is eczema common on thighs?

Eczema can affect any part of the body, including the thighs. However, eczema is most common on the hands in adults, while children more commonly get eczema inside the elbows, on the backs of the knees, and on the face and scalp.

How can a person get rid of eczema on their thighs?

There is no cure for eczema, so it may not be possible for a person to get rid of it entirely. However, the following treatments and tips may help ease the symptoms of eczema on a person’s thighs:

  • using a moisturizer every day
  • using topical corticosteroids
  • taking antihistamines for severe itching
  • wrapping a bandage around the thigh to allow the skin underneath to heal
  • identifying triggers for eczema and avoiding them

What does a rash on the inner thigh mean?

A rash on the inner thigh could point to several causes, including:

  • eczema
  • chafing
  • heat rash
  • hidradenitis suppurative (HS)
  • a sexually transmitted infection (STI), such as genital herpes
  • a genital yeast infection such as vaginal yeast that spreads, or jock itch

A rash on the inner thigh is a common symptom with many underlying causes. Most cases of inner thigh rash are not serious, but it is important to speak with a doctor to determine the exact cause and receive appropriate treatments.

There are many medical treatments and home remedies that will effectively treat an inner thigh rash. Some rashes may not require any treatment at all and will resolve on their own with time.

Furthermore, by using the preventive techniques listed above, a person may avoid inner thigh rash altogether.