What Is Psoriasis?
There are several forms of psoriasis. The typical form causes itchy or sore patches of thick, red skin covered with silvery scales. Although they can appear anywhere on the body, the patches occur mostly on the elbows, knees, other parts of the legs, scalp, lower back, face, palms, and soles of the feet. Psoriasis may also affect the fingernails, toenails, the soft tissues of the genitals, and inside the mouth. Some people get psoriatic arthritis in which the joints become inflamed and painful.
- Psoriasis is a chronic (long-term) disorder of the immune system, which defends the body against infection and disease.
- It causes scaling and inflammation of the skin.
- More than 5 million Americans have psoriasis.
- You cannot catch the disease from other people.
- Stress, dry skin, infections and certain medicines could make it worse.
- In many cases, there is a family history of psoriasis. Researchers have identified genes linked to the disease.
- There are more options than ever to help patients cope with psoriasis.
What Causes Psoriasis?
Psoriasis is a disorder of the immune system, which defends the body against infection and disease. In psoriasis, white blood cells—called T cells—become overly active. This causes inflammation—pain, swelling, heat, and redness. It also leads to fast turnover of skin cells. Normally skin cells grow deep in the skin and slowly rise to the surface. With psoriasis, it can happen in just a few days because the cells rise too fast and pile up on the surface. In many cases, there is a family history of psoriasis. Researchers have identified genes linked to the disease.
People with psoriasis may notice times when their skin problems get worse. These are called flares. Flares may be due to infection, stress, or dryness of the skin. Certain medicines, such as beta-blockers for high blood pressure, may trigger or worsen the disease. Sometimes psoriasis will appear after a cut, scratch, sunburn, or an infection.
How Does Psoriasis Affect Quality of Life?
People with psoriasis may have significant physical discomfort and some disability. Because of itching and pain, they may have trouble taking care of themselves or others. Walking and sleeping may be difficult. Medical care is frequent and costly and can disrupt work and school schedules. People with psoriasis may feel self-conscious about their appearance. That can lead to depression and social isolation.
How is Psoriasis Diagnosed?
Psoriasis may be difficult to diagnose. It often looks like other skin diseases, such as eczema. Examining a small skin sample under a microscope can help your doctor make the diagnosis.
There are several types of psoriasis, including:
- Plaque – Skin lesions (damaged areas) are red at the base and covered by silvery scales.
- Guttate – Small, drop-shaped lesions on the trunk, limbs, and scalp. It is most often set off by upper respiratory infections such as a sore throat from streptococcal bacteria.
- Pustular – Blisters of noninfectious pus on the skin, possibly caused by medicines, infections, stress, or exposure to certain chemicals.
- Inverse – Smooth, red patches in the folds of the skin near the genitals, under the breasts, or in the armpits. Symptoms may be worsened by friction and sweating.
- Erythrodermic – Widespread reddening and scaling of the skin may be a reaction to severe sunburn or to taking cortisone or other medicines. It can also be caused by prolonged, poorly controlled psoriasis. Erythrodermic psoriasis can be very serious and requires immediate medical attention.
Some people with psoriasis also develop psoriatic arthritis, a form of arthritis that causes inflammation, pain, and stiffness in the joints.
What Research Is Being Conducted on Psoriasis?
To stop psoriasis, researchers are looking at how skin cells form healthy skin, as well as the mechanisms that cause skin lesions. Significant progress has been made in understanding a number of the genes, either known or suspected, to be involved in psoriasis. Some studies are trying to determine the genes responsible for causing itching.
Researchers also have been studying new treatments to quiet immune system reactions in the skin. These include blocking the activity of T cells or the proteins (cytokines) that promote inflammation. If ways can be found to target only the disease-causing immune reactions, resulting treatments could benefit psoriasis patients as well as those with other autoimmune diseases.
Patients, especially those with severe psoriasis, may be at greater risk of cardiovascular problems, as well as obesity, high blood pressure, and diabetes. So researchers also are trying to understand how these conditions are associated and how best to treat patients.