The inner thighs are a common area for rashes of all kinds. This area tends to be hot, dark, and sweaty with limited airflow. This makes it the perfect breeding ground for bacteria and fungi.
The inner thighs also see a lot of skin irritation, due to them rubbing together and their exposure to allergens in clothing material or detergents. Inner thigh rashes affect both men and women, although certain types — jock itch, for example — are seen more often in men, while other types affect more women.
Symptoms of an inner thigh rash are a lot like those of other rashes you’d see on your body. They include:
- pimple-like red bumps
- red, scaly patches
- clusters of blisters
The rashes can:
- cause discomfort or pain
Types and causes
Here are some inner thigh rashes and their causes:
This rash also goes by the name of tinea cruris and ringworm of the groin. It’s common in men — mostly because they sweat more than women, creating a moist environment, and because their genitalia generates a lot of heat.
Jock itch is actually a misnomer, because athletes aren’t the only ones who get it. It’s also caused by the same fungus that causes athlete’s foot. The rash often takes on a reddish half-moon shape on the inner thigh area with small, weeping, blisters and patches of scaly skin on the border. It can be itchy and burning.
The rash is contagious, spread via skin-to-skin contact and the sharing of towels or other personal items. While it’s not common in women, they’re not immune to it.
Contact dermatitis occurs when the skin comes into contact with something it’s allergic to — think poison ivy or nickel in jewelry — or irritated by, for example a material in clothing or a fragrance in detergent. The former is called irritant dermatitis and it accounts for 80 percent of all contact dermatitis.
While any part of the body can be affected, the inner thighs are a common one due to the rubbing together of thighs — and, thus, exposure to clothing or detergent irritants. Skin becomes inflamed, red, and itchy or burning.
Also known as prickly heat, this rash looks like clusters of small red pimples that may itch or feel “prickly.” It generally occurs where skin touches skin and occurs when sweat glands become blocked.
As the name implies, heat rash most often occurs in hot, humid weather and environments. In fact, it’s estimated that 20 percent of the population get heat rash in the summer, usually infants and young children. But it can happen to anyone.
Razor burn is skin irritation, usually characterized by small red bumps. It’s caused by shaving delicate skin. It’s different from razor bumps, which are caused by ingrown hairs. Irritation is due to dull razor blades, bacteria on razor blades, and an improper shaving technique such as pressing too hard on the blade.
According to the American Osteopathic College of Dermatology (AOCD), this is a common rash that tends to appear more often in the spring and fall, in the young versus the old, and in women as opposed to men.
The AOCD also reports that in about 75 percent of cases, the rash — which is usually found on the neck, trunk, arms, and thighs — starts with what’s called a “herald” patch. This patch is usually oval and scaly. In a few weeks, smaller, scaly patches develop.
No one is exactly sure what causes pityriasis rosea, but some speculate it may be related to human herpesvirus type 7 (HHV-7). Many of us have already been infected with HHV-7 as children, and therefore are immune to it, which may help explain why the rash is generally not contagious. It tends to disappear a few weeks after it pops up.
When skin rubs against skin, as can happen with the inner thighs, irritation and even blistering can ensue. This commonly happens when women wear short shorts or skirts without pantyhose. Chafing can also happen during physical activities, like running with shorts that rise up.
This is a rare rash that’s generally caused by blocked hair follicles in areas with lots of sweat glands and where skin rubs against skin, namely the armpits and the inner thighs and groin area.
Hidradenitis suppurativa usually shows up as blackheads or painful red bumps under the skin. These bumps can break open and ooze pus. While it can be treated, treatment is usually slow and the rash can recur. Doctors aren’t sure what causes it, but they suspect genetics, hormones, or even lifestyle factors, like being a smoker or overweight, plays a role. It isn’t contagious and isn’t due to poor hygiene.
Possible STD causes
A few sexually transmitted diseases can also produce rashes.
- Genital herpes. This STD can produce small red bumps, which progress to blisters, on the penis, scrotum, anus, buttocks, vaginal area, and inner thighs. The blisters are painful and itchy.
- Secondary syphilis. When syphilis progresses from primary to secondary, penny-sized sores can occur anywhere on the body.
Your doctor will make a diagnosis based on your symptoms, medical history, and a visual examination of the rash. If more confirmation is needed, you doctor may scrape a sample of the rash and send it off to a lab for testing.
Treatment depends on the type of rash and its causes. Rashes caused by fungal infections, such as jock itch, are treated with over-the-counter (OTC) antifungal ointments and sprays. If the rash is chronic or severe, your healthcare provider may recommend prescription-strength antifungals.
Other rashes that cause inflamed skin can be treated with topical or oral steroids — prescription or OTC. And itchiness can be reduced with antihistamines, such as Benadryl. Some rashes, namely pityriasis rosea, will go away on their own often without treatment.
Home remedies and prevention
There are dozens of lifestyle changes you can implement to prevent an inner thigh rash from developing, or speed healing if you already have the rash. They include:
- Keeping the area dry. Make sure you thoroughly dry yourself after bathing and after wearing wicking fabrics — usually synthetic materials like polyester or a polyester-cotton blend. Also change your clothes as soon as possible after you’ve worked out or gotten sweaty.
- Dressing appropriately for the weather. Overdressing can lead to rashes.
- Avoiding hot showers or baths. Bathing with temperate water is best.
- Losing weight if necessary. Rashes often develop in folds of the skin — the fewer folds, the less likely rashes will occur.
- Avoiding sharing personal items. Especially items like towels or clothing.
If you have a rash:
- Apply cool compresses to soothe irritation and reduce itching. Oatmeal baths help, too.
- Use OTC hydrocortisone creams or antihistamines (with your doctor’s approval) to help relieve itching.
- Avoid anything you think may be irritating your skin.
Inner thigh rashes are common, but most aren’t serious. Taking precautions, practicing simple prevention methods, and seeking prompt treatment will all go a long way in staving off an inner thigh rash — or getting rid of one quickly if it does erupt.