Psoriasis is a persistent, long-lasting (chronic) disease that is not contagious. While the exact cause of psoriasis is unknown, scientists believe the immune system mistakenly activates a reaction in the skin cells that causes itchy skin spots, patches, and lesions to form. Generally, there are 5 major types you should know about.
This is the most common form of psoriasis. It’s characterized by raised, inflamed, red lesions covered by silvery white scales. Typically, it’s found on the elbows, knees, scalp, and lower back. About 80% of those who have psoriasis have this type.
Guttate psoriasis often starts in childhood or young adulthood. It appears as small, red, individual spots on the skin of the torso, arms, and legs. These spots are not usually as thick as plaque lesions.
Found in the armpits, groin, under the breasts, and in other skin folds around the genitals and the buttocks. This type of psoriasis appears as bright-red lesions that are smooth and shiny.
Primarily seen in adults, pustular psoriasis is characterized by white blisters of noninfectious pus surrounded by red skin. It may either be localized to certain areas of the body, such as the hands and feet, or covering most of the body.
A particularly inflammatory form of psoriasis affecting most of the body surface, it is characterized by periodic, widespread, fiery redness of the skin and the shedding of scales in sheets.
Before your dermatologist can decide on a psoriasis treatment approach, he or she must first determine the severity of your psoriasis. This typically involves assessing the percentage of body surface area (BSA) affected and should also take into account other aspects of the disease, such as the location of your plaques, your symptoms, and the impact of psoriasis on your quality of life.
Everyone reacts differently to his or her condition. For example, someone with only a few small patches of psoriasis may be overwhelmed by the disease, especially if it occurs on a more vulnerable part of the body. On the other hand, someone whose psoriasis covers over 50% of his or her body may not be bothered by it and may be able to lead a normal life.
Both the American Academy of Dermatology (AAD) and the National Psoriasis Foundation recommend that dermatologists also consider quality-of-life issues when determining disease severity and when developing a psoriasis treatment plan. That's why it's important to tell your dermatologist about your physical symptoms as well as how your psoriasis affects you emotionally and socially. By taking all of these aspects into account, your dermatologist may be able to offer you appropriate psoriasis treatment options.
Depending on the severity of your psoriasis—mild, moderate, or severe—your doctor will determine whether you are a candidate for localized therapies or if systemic therapies are more appropriate.
Topical treatments: creams, lotions, and ointments that are applied to the surface of the skin
Biologics: a different kind of systemic medication that works in a targeted way on the immune system
Phototherapy: artificial ultraviolet light, or a combination of ultraviolet light and medications
Psoriasis Commonly Asked Questions