Redness or other discoloration and itching are common symptoms of several conditions, such as dermatitis, intertrigo, erythrasma, and more. If you have these symptoms in the groin area, thighs, or buttocks, it might also be caused by inverse psoriasis or jock itch.

The symptoms of inverse psoriasis and jock itch are similar and sometimes mistaken for each other, but there are a few key differences.

Keep reading to learn more about these two conditions, including their risk factors and treatment options.

Inverse psoriasis is an unusual form of psoriasis. Psoriasis is a chronic (long-term) autoimmune disease caused at least partly by genetics.

An autoimmune disease can develop when your body’s immune system views your healthy cells as foreign objects. The body begins to attack these cells as a defense against a perceived threat.

Inverse psoriasis appears in areas where skin rubs against skin, including the:

  • groin
  • armpits
  • inner thigh regions
  • under breasts
  • between the buttocks

A 2016 study estimates that between 24 and 30 percent of people living with psoriasis have inverse psoriasis.

This data may not tell the entire story, as psoriasis on darker skin tones isn’t always recognized as it is for those who have lighter skin tones. As a result, People of Color with psoriasis may be disproportionately undertreated and misdiagnosed.

Jock itch is the common name for a fungal infection called Tinea cruris. It may occur in the:

  • groin area
  • thighs
  • buttocks

Unlike psoriasis — which has a more complex cause — doctors know fungi called dermatophytes cause jock itch. These fungi are similar to those that lead to ringworm.

Psoriasis comes in different forms. On light and fair skin tones symptoms include raised, red or pink patches of skin that are occasionally paired with a silvery scale.

On medium skin tones, it tends to be salmon-colored with silvery-white scales. On darker skin tones, the patches are more likely to appear as violet or dark brown patches.

Additionally, itching or bleeding may also occur.

These skin patches, also known as plaques, can show up anywhere on your body. Plaque psoriasis commonly appears on the:

  • elbows
  • knees
  • lower back
  • buttocks
  • scalp

Inverse psoriasis most often shows up in folded areas of the body or wherever skin touches skin, says Aleksandr Itkin, MD, FAAD, a dermatologist at Scripps Clinic in San Diego, California.

Inverse psoriasis on light skin appears as bright red lesions on body folds and tends to be smooth and shiny. On darker skin, it can appearin the body folds as lesions of purple, brown, or darker than the surrounding skin.

According to Itkin, this type of psoriasis is often mistaken for fungal infections such as jock itch. This is because of its common appearance in the groin area.

Jock itch can also cause redness in the groin area, as well as:

  • itching
  • burning
  • overall irritation

You may also see scaling, which can appear on the thighs or buttocks.

How do you tell the difference? According to Itkin, one of the main ways doctors can tell the difference is by looking at what’s called “demarcation.”

Fungal infections usually cause fine, elevated scales at the leading reddish edge of the lesion. The center of the lesion becomes brownish. On lighter skin tones, the affected areas can appear red, flaky, or scaly. On darker skin tones, the rash might appear gray or brown.

Inverse psoriasis usually doesn’t have this scale. If it does, it’s probably more evenly distributed over the patch of skin.

If someone in your family has psoriasis, your chances of having it increase. Smoking and stress can also increase your risk of triggering the disease.

Having obesity or overweight is also a risk factor for jock itch because the fungus can live in skinfolds. The fungus multiplies in warm, moist places. People who sweat more, such as athletes, are also more likely to develop jock itch.

There’s no permanent cure for psoriasis, but there are treatments. They can include:

These treatments will address the symptoms as well as the underlying immune dysfunction. So while they usually won’t cure the condition entirely, symptoms are less likely to reoccur.

You can usually treat jock itch with topical creams and oral medications. Some of these medications are available over the counter at your local drugstore.

Good personal hygiene can prevent future cases of jock itch or other fungal infections. Change your undergarments if they become saturated with sweat, secretions, or water. Shower immediately after participating in any sports.

Make an appointment with a doctor if your symptoms last longer than 10 days. This is especially true if your symptoms worsen or don’t respond to an over-the-counter fungal treatment.

Getting an accurate diagnosis is the best way to start feeling better faster.

Psoriasis and genes

There seems to be a genetic link with psoriasis. According to the National Psoriasis Foundation, psoriasis may occur in people with no genetic history of the disease, but having a family member with the disease increases the risk.