Inverse psoriasis (also known as intertriginous psoriasis) shows up as very red lesions in body folds. It may appear smooth and shiny. Many people have another type of psoriasis elsewhere on the body at the same time.
Inverse psoriasis is found in the armpits, groin, under the breasts and in other skin folds on the body.It is particularly subject to irritation from rubbing and sweating because of its location in skin folds and tender areas. It usually lacks the scale associated with plaque psoriasis due to the moist environment. It is more common in overweight people and people with deep skin folds.
Treatment can be difficult due to the sensitivity of the skin in these areas. Steroid creams and ointments are considered very effective, but they should not be occluded (covered) with plastic dressings. Because the skin is thinner in areas that typically have inverse psoriasis, the risk of side effects from topically applied medicine increases. This is due to the rapid absorption of medication in thin, sensitive skin. Overuse or misuse of steroids can further thin the skin and cause stretch marks. Because these areas are prone to yeast and fungal infections, doctors also may test for infection. If present, they may prescribe diluted topical steroids in combination with other medications. An example is 1 percent or 2 percent hydrocortisone with anti-yeast or anti-fungal agents. Compared to more modern treatment options, Castellani's Paint is not commonly used unless there are clear signs of a secondary bacterial or fungal infection. Castellani's Paint is a prescription that can be used to help dry out oozing, infected areas.
Other topical agents, such as calcipotriene (brand name Dovonex), coal tar or anthralin, can be somewhat effective in treating psoriasis in skin folds. However they also may be irritating. They should be used with caution and under the direction of a health care provider.
Tacrolimus (brand name Protopic) and pimecrolimus (brand name Elidel) are two topical medications approved by the U.S. Food and Drug Administration for the treatment of eczema. Many dermatologists have found they work well for psoriasis lesions in the skin folds. People with severe inverse psoriasis may occasionally require UVB (ultraviolet B) light therapy or biologic medications to control the condition.