A common and chronic condition, psoriasis typically causes patches of itchy, scaly and sometimes inflamed skin. Although they can appear anywhere, these patches, called plaques, are most likely to crop up on your knees, elbows, hands, feet, scalp or back. In some cases, the fingernails and toenails are also affected.
The symptoms of psoriasis can vary a great deal depending on its severity, ranging from mildly annoying to truly debilitating.
While the itchiness and pain can be unpleasant to say the least, some of the worst effects can be emotional. People with severe psoriasis sometimes are so overwhelmed by their condition and self-conscious of their appearance that they feel isolated and depressed.
Researchers estimate that up to seven million people in the U.S. have psoriasis, about 1% to 2% of the population. Unfortunately, there isn’t a cure for this condition, but there are a number of effective treatments that can help keep it under control.
What Causes Psoriasis?
Normally, skin cells are constantly being formed, then pushed up to the surface where they eventually die and flake off, revealing new skin cells. In people with psoriasis, however, the skin cells grow too quickly, causing layers of skin to build up, forming a whitish, flaky crust. Blood vessels increase flow in an attempt to nourish this skin, causing reddened inflammation. Thus the hallmark symptoms are reddened, inflamed skin with a whitish, flaky layer of dead cells on top.
Although psoriasis usually appears as a skin condition, recent discoveries show that its real cause is a problem with the immune system.
Your body naturally fights infections and heals injuries with special cells — called white blood cells — that are designed to battle viruses or bacteria. Normally these cells go to the site of infection or injury and release antibodies and other chemicals to repair wounds, clot blood and prevent infection. One byproduct of this normal process is inflammation (redness and swelling).
For reasons that doctors don’t yet understand, the immune systems of people with psoriasis malfunction. One type of white blood cell – the B-cell – begins creating antibodies that destroy normal skin cells. Another type of white blood cell – the T-cell – begins overproducing a substance called cytokines. This overproduction turns off a signal that regulates skin cell growth.
That’s why this condition is considered an immune-mediated disease.
Psoriasis of the skin or nails may look like a rash or fungus, but you can’t catch it from another person and you can’t give it to anyone else. You also can’t spread it from one part of your body to another by touch. Experts now know that a susceptibility to getting psoriasis can be inherited. If it runs in your family, your chances of developing psoriasis are higher.
Types of Psoriasis
There are several different types of psoriasis. About 90% of all cases of psoriasis are plaque psoriasis, but other varieties include:
- Guttate psoriasis. This form of psoriasis usually affects children, teenagers, and young adults. It often appears after a bacterial infection, such as strep throat. Its typical symptoms are the appearance of red, scaly, raindrop-shaped spots on the skin, usually over the abdomen, arms, legs and scalp. It can often clear up on its own without treatment.
- Pustular psoriasis. The typical symptoms of pustular psoriasis are pus-filled blisters on the skin. The blisters usually dry up, turn brown, become scaly and peel off. The lesions usually occur on the hands and feet.
- Erythrodermic psoriasis. Symptoms include red and scaly skin over large areas of the body. This condition can evolve from other forms of psoriasis or be triggered by psoriasis treatment. It can also be triggered by withdrawal from drugs such as corticosteroids (often taken for diseases such as asthma).
- Inverse psoriasis. In people with this condition, dry and bright red patches appear in folds of skin, for instance under the breasts, in the armpits, or on the genitals. This type of psoriasis can be exacerbated by obesity.
Progression of Psoriasis
Psoriasis doesn’t have any set way of progressing — it develops differently depending on the person. While some people may only have occasional and minor symptoms for their entire lives, others may have to cope with severe symptoms on a regular basis.
In most people, the symptoms come and go. Flare-ups might be brought on by some of the conditions mentioned above, such as dry weather or stress.
Untreated, extremely severe psoriasis can be dangerous. Although it happens very rarely, if lesions cover enough of the body, it’s possible for the immune system to become overwhelmed trying to fight off infections. This increases your risk of developing serious bacterial infections. Be sure to see your doctor immediately if your psoriasis spreads to cover large parts of your body or if you show signs of infection, such as fever.
Your board-certified dermatologist or advanced practitioner will tailor your psoriasis treatment based on your skin’s condition, which can include topical therapies, XTRAC, Narrow Band UVB phototherapy, oral systemic medications and biologics.