Psoriasis is a common skin condition that causes skin redness and irritation. Most people with psoriasis have thick, red skin with flaky, silver-white patches called scales.
Psoriasis is a very common condition. The disorder may affect people of any age, but it most commonly begins between ages 15 and 35.
The condition cannot be spread to others.
Psoriasis seems to be passed down through families. Doctors think it probably occurs when the body’s immune system mistakes healthy cells for dangerous substances. See also: Inflammatory response
Skin cells grow deep in the skin and normally rise to the surface about once a month. In persons with psoriasis, this process is too fast (about 2 weeks instead of 4 weeks) and dead skin cells build up on the skin’s surface.
The following may trigger an attack of psoriasis or make the condition more difficult to treat:
Bacteria or viral infections, including strep throat and upper respiratory infections
Dry air or dry skin
Injury to the skin, including cuts, burns, and insect bites
Some medicines, including antimalaria drugs, beta-blockers, and lithium
Too little sunlight
Too much sunlight (sunburn)
Too much alcohol
In general, psoriasis may be severe in people who have a weakened immune system. This may include persons who have:
Autoimmune disorders (such as rheumatoid arthritis)
Up to one-third of people with psoriasis may also have arthritis, a condition known as psoriatic arthritis.
Psoriasis can appear suddenly or slowly. In many cases, psoriasis goes away and then flares up again repeatedly over time. People with psoriasis have irritated patches of skin. The redness is most often seen on the elbows, knees, and trunk, but it can appear anywhere on the body. For example, there may be flaky patches on the scalp. The skin patches or dots may be:
Dry and covered with silver, flaky skin (scales)
Pink-red in color (like the color of salmon)
Raised and thick
Other symptoms may include:
Genital lesions in males
Joint pain or aching (psoriatic arthritis)
Nail changes, including nail thickening, yellow-brown spots, dents (pits) on the nail surface, and separation of the nail from the base
Severe dandruff on the scalp
Psoriasis may affect any or all parts of the skin. There are five main types of psoriasis:
Erythrodermic — The skin redness is very intense and covers a large area.
Guttate — Small, pink-red spots appear on the skin.
Inverse — Skin redness and irritation occurs in the armpits, groin, and in between overlapping skin.
Plaque — Thick, red patches of skin are covered by flaky, silver-white scales. This is the most common type of psoriasis.
Pustular — White blisters are surrounded by red, irritated skin.
The goal of treatment is to control your symptoms and prevent infections. In general, three treatment options are used for patients with psoriasis:
Topical medications such as lotions, ointments, creams, and shampoos
Body-wide (systemic) medications, which are pills or injections that affect the whole body, not just the skin
Phototherapy, which uses light to treat psoriasis
Most cases of psoriasis are treated with medications that are placed directly on the skin or scalp:
Cortisone creams and ointments
Creams or ointments that contain coal tar or anthralin
Creams to remove the scaling (usually salicylic acid or lactic acid)
Dandruff shampoos (over-the-counter or prescription)
Prescription medicines containing vitamin D or vitamin A (retinoids)
If you have an infection, your doctor will prescribe antibiotics. You may try the following self-care at home:
Oatmeal baths may be soothing and may help to loosen scales. You can use over-the-counter oatmeal bath products. Or, you can mix 1 cup of oatmeal into a tub of warm water.
Sunlight may help your symptoms go away. Be careful not to get sunburned.
Relaxation and antistress techniques may be helpful. The link between stress and flares of psoriasis is not well understood, however. Some people may choose to have phototherapy which is a medical treatment in which your skin is carefully exposed to ultraviolet light. Phototherapy may be given alone or after you take a drug that makes the skin sensitive to light.Persons with very severe psoriasis may receive medicines to suppress the body’s immune response. These medicines include methotrexate or cyclosporine. (Persons who have psoriatic arthritis may also receive these drugs.) Retinoids such as acitretin can also be used.Psoriasis is a life-long condition that can be controlled with treatment. It may go away for a long time and then return. With appropriate treatment, it usually does not affect your general physical health.