This type of psoriasis is the inverse — or opposite — of the more common plaque psoriasis, which occurs on the outer, extensor surfaces of the body, such as the knees and elbows. Psoriasis, in general, is a genetic condition passed down through families. “It’s likely that multiple genes need to be affected to allow psoriasis to occur, and that it’s frequently triggered by an external event, such as an infection,” says James W. Swan, MD, professor of dermatology at the Loyola University Stritch School of Medicine in Maywood, Illinois. In the case of inverse psoriasis, the triggers also involve friction and dampness, and are associated with sweating. Inverse psoriasis occurs in 2 to 6 percent of people with psoriasis and most often alongside some other form of the condition, such as plaque psoriasis. It’s more common in people who are overweight or obese or have deep skin folds. People who are middle-aged or seniors are more likely to develop flexural psoriasis than younger people. Inverse psoriasis can be one of the most painful and irritating forms of the disease, due to the location of the lesions around the genitals and armpits and underneath the breasts and buttocks. The affected skin becomes very tender, and is further irritated by sweating and skin rubbing against itself. Sometimes a crease in the center of an inverse psoriasis lesion will crack open, creating the possibility of bleeding or infection.
Treatment Options
Treatment of inverse psoriasis is difficult due to the location of the lesions. Skin folds often prove to be some of the most sensitive skin on the body, which increases the risk of a reaction to many of the topical drugs available for psoriasis treatment. Doctors often must treat not only the psoriasis, but also accompanying infections caused by yeast or fungus. Inverse or flexural psoriasis treatments include: Corticosteroids These topical medications suppress the immune system and reduce inflammation, but also can cause thinning of the skin and must be used carefully on the already-thin skin located in skin folds. If the patient has tested positive for infection, doctors will sometimes use diluted topical steroids mixed with other medication — for example, a 1 or 2 percent hydrocortisone cream blended with anti-yeast or anti-fungal medicine. Calcipotriene This cream or ointment contains a synthetic form of vitamin D3 that can slow skin cell turnover. It can irritate the skin, too, so it must be used carefully in treating flexural psoriasis. It isn’t recommended for use on the genitals. Coal Tar This soothing agent comes in gels or ointments that can be applied to lesions. It also is available as a liquid that can be added to bath water to help relieve symptoms. Castellani’s Paint This product, with the active ingredient phenol, can be prescribed or bought over the counter under the brand name Castederm. It’s a liquid that is painted on and can help dry lesions in skin folds that have become moist. Light Therapy Also known as phototherapy, this involves exposing lesions to ultraviolet light, either through natural sunlight or by spending time under a sun lamp. You may be prescribed a medication to accompany the light therapy, to enhance the body’s response. Systemic Medication People with severe inverse psoriasis may need to take pills or receive injections to help treat their symptoms. Options include immunosuppressive medicines, like Trexall (methotrexate) and Restasis (cyclosporine), or biologic drugs that target specific immune reactions. While inverse psoriasis is very painful, there are several approaches to treating it. Talk with your doctor or dermatologist about the best way to ease your symptoms and find relief.
