Psoriasis is an autoimmune disease that affects your skin. Autoimmune diseases are conditions in which your immune system attacks your body. In the case of psoriasis, your skin cells multiply too quickly.

The faster life cycle of skin cells causes a variety of symptoms that you’ll see on your skin. These range from scaly, silvery lesions and red patches to areas of pus-filled sores.

Symptoms depend on the type of psoriasis you have. Inverse psoriasis is one of several types.

What is inverse psoriasis?

Inverse psoriasis, sometimes called hidden psoriasis or intertriginous psoriasis, is a form of psoriasis that affects skin folds. These are areas of your body where skin rubs against skin.

Inverse psoriasis can occur under your arms, under a woman’s breasts, or in the groin or inner thigh area.

People who have inverse psoriasis often have another form as well, like plaque psoriasis, on other parts of their body. While raised lesions of dry, scaly skin — a key sign of plaque psoriasis — often cover large sections of your body, inverse psoriasis tends to appear in smaller patches.

Inverse psoriasis is known for its red, shiny, smooth rash. Unlike the scales, pustular spots, and crusting skin associated with other forms of psoriasis, the rash caused by inverse psoriasis is neither raised nor dry.

Inflamed patches of skin are sometimes moist to the touch. You may feel irritation, itching, or both in areas that are affected by inverse psoriasis.

You’re also at risk to develop a yeast infection in the skin folds due to the moist environment. The red lesions generally cover very large areas within your skin folds.

Inverse psoriasis is caused by an abnormality in your immune system, just like other autoimmune diseases. But moisture (in the form of sweating) and friction can trigger the symptoms of this particular type of psoriasis.

If you’ve got psoriasis and are overweight, you’re at a higher risk of also developing inverse psoriasis. That’s because extra body weight produces excess skin and deeper skin folds.

There are several different treatment methods available for inverse psoriasis:

Topical treatment

Topical creams, which are types of medication that you rub into your skin, are the first-line treatment method for inverse psoriasis.

The goal of treatment is to reduce inflammation and discomfort in these sensitive areas. Because the skin folds are so sensitive, medications must be used carefully.

Steroid creams can successfully reduce inflammation, but can also cause the skin to become thinner and more sensitive. If you’re prescribed a topical treatment, your doctor will monitor your progress and adjust the dosage if there are signs of skin thinning.

Topical medicines are usually used in the morning after you shower and once again before bedtime.

Alternatives to topical steroids are topical calcineurin inhibitors, tacrolimus, and pimecrolimus, which will stop the body’s immune system from producing substances that may cause skin disease.

Infected inverse psoriasis treatment

Because inverse psoriasis is prone to yeast and fungal infections, your doctor may dilute topical steroids and add anti-yeast and anti-fungal agents.

Phototherapy

Phototherapy is a treatment option for people with moderate to severe inverse psoriasis. Phototherapy is the medical term for light therapy.

A form of ultraviolet light called UVB rays can effectively slow the growth of skin cells in some people with psoriasis.

Treatment with phototherapy involves using a light box that produces artificial UVB rays for a specified amount of time each session.

With phototherapy, your psoriasis might temporarily get worse before it gets better. Let your doctor know of any concerns about your rashes during light therapy treatment.

Systemic drugs

If your inverse psoriasis isn’t getting better with topical medications and phototherapy, your doctor might prescribe systemic drugs. These are medications taken either by mouth or injection.

One type of systemic drug is a biologic — a type of medication that changes the way your immune system works. Biologics use proteins to block the response of your immune system so it won’t attack your body as much.

If biologics are used as a treatment, your doctor will give you an injection or intravenous infusion of biologic drugs on a regular schedule. You might also continue with phototherapy or topical treatments at the same time.

Other systemic drugs that may be used are methotrexate or cyclosporine (Sandimmune), which moderate the immune system to decrease the action of certain skin cells.

The symptoms of inverse psoriasis can be very uncomfortable. There are some steps you can take to increase your comfort levels, both physically and emotionally.

Wear clothing that lets your skin breathe. Cotton and other natural fibers are soft against the skin. Loose tops won’t rub against your sore skin and can help prevent moisture from getting trapped in your skin folds.

You can also powder your affected areas to absorb moisture with corn starch, baking soda, or zinc oxide.

Try out different styles of dress to determine what works best for you as you treat the condition.