There is now no question that psoriasis is an inherited systemic inflammatory disease of immune dysfunction whose most obvious clinical feature is a plaque of elevated, inflamed skin. Plaques are scaly, red, bumpy areas of skin that are often itchy. They characteristically are found on the scalp, elbows, and knees. Plaque psoriasis is relatively common; about 2%-3% of the population of the United States is affected.
The characteristic cutaneous finding in psoriasis is a small scaly, red bump. These bumps generally join together into elevated plaques of skin and most often are visible on the elbows, knees, and scalp, although any area of skin can be involved. Frequently, these plaques are quite itchy. Rarely, most of the skin surface is affected.
Usually dermatologists and most primary-care professionals are able to diagnose classical psoriasis on the basis of the appearance of the individual lesions, the tendency to form plaques, and the distribution of those plaques on the elbows, knees, and scalp. Psoriasis can affect one or all the nails of the fingers and toes, causing changes that resemble fungal infections. Psoriasis rarely involves the lips or mouth. Occasionally, atypical psoriasis may require a biopsy (a small piece of surgically removed involved skin) be examined under the microscope to supplement the clinical evaluation. Blood tests are rarely helpful to confirm or support the diagnosis.
What Causes Psoriasis?
Like many other diseases, there is a significant interplay of genetic and environmental factors. Certain mutations pave the way for the development of the disease. It seems likely that more than one mutation in more than one gene is necessary to develop psoriasis. Once the genes are inherited, some sort of environmental factor is necessary to activate it. Such a factor could be a common viral or bacterial infection or even a simple injury.
Inverse psoriasis is a painful and difficult type of psoriasis that forms in the body’s skin folds, such as the armpits, genitals, and under the breasts or buttocks. Because these skin folds are called flexures, it also is known as flexural psoriasis. 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. The immune system causes the skin to begin producing too many new skin cells, spurring skin cell turnover. While psoriasis is genetic in nature, researchers believe some environmental factor triggers it. In the case of inverse psoriasis, the triggers are friction and dampness, associated with sweating.
Inverse psoriasis occurs in 2 to 6 percent of people with psoriasis and most often alongside some other type of psoriasis, such as plaque psoriasis. It is 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 contract flexural psoriasis than younger people.
Inverse Psoriasis Symptoms
The first signs of inverse psoriasis are very deep red patches of skin in body folds. These lesions tend to be shiny and smooth — the moistness of the affected area prevents the development of the dry skin scales that accompany other types of psoriasis.
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.
Inverse Psoriasis Treatment
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, whichincreases the risk of a reaction to many of the topical medications 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: