Psoriasis a complicated and persistent skin disease that got its name from the Greek word for "itch." The skin can become inflamed, with thickened red, areas with shiny scales. The scalp, elbows, knees, face, lower back, groin and genitals, arms, legs, palms and soles, body folds and nails are the areas most commonly affected by psoriasis. Oftentimes it will appear in the same place on both sides of the body.
The most common form of psoriasis is called "plaque psoriasis" - about 80 percent of people with psoriasis have this type.
Psoriasis can be a condition of extremes. In some cases it is so mild that people don't know they have it. Other cases are so severe that it can cover large areas of the body. The good news is that there are treatments and medications that help even the most severe cases.
It is estimated that in the United States two out of every hundred people have psoriasis. Approximately 150,000 new cases occur each year. Psoriasis is not contagious. It often runs in families because it has a genetic component that makes certain people more likely to develop it.
WHAT CAUSES PSORIASIS?
The cause is unknown. Some studies, however, point to an abnormality in the functioning of key white cells in the blood stream triggering inflammation in the skin. Because of the inflammation, the skin sheds too rapidly and produces the red, silvery scales. Psoriasis can also be triggered by infections, emotional stress, injuries to the skin and reactions to certain drugs. Flare-ups are often worse in the winter, because of dry skin and a lack of sunlight.
TYPES OF PSORIASIS
Psoriasis can differ in severity, duration, location, and in shape and pattern. The most common form begins with little red bumps. The bumps can grow larger and then scales form. While the top scales flake off easily and often, scales below the surface stick together. When they are removed, the tender, exposed skin bleeds. These small red areas then grow, sometimes becoming quite large.
Psoriasis affecting nails have tiny pits on them. Nails may loosen, thicken or crumble. Nail psoriasis can be difficult to treat. Inverse psoriasis occurs in the armpit, under the breast and in skin folds around the groin, buttocks, and genitals.
HOW IS PSORIASIS DIAGNOSED?
Dermatologists diagnose psoriasis by examining the skin, nails, and scalp. If the diagnosis is in doubt, a skin biopsy is usually helpful.
HOW IS PSORIASIS TREATED?
The goal is to reduce inflammation and to control shedding of the skin. Moisturizing creams and lotions loosen scales and help control itching. Special diets have not been successful in treating psoriasis, except in isolated cases.
Treatment is based on a patient's health, age, lifestyle, and the severity of the psoriasis. Different types of treatment, including light therapy (which requires several visits) may be needed.
Our providers may prescribe topical medications to apply to the skin containing cortisone-like compounds, synthetic vitamin D, or tar-derived products. These may be used in combination with natural sunlight or ultraviolet light. The most severe forms of psoriasis may require oral or injectable medications, with or without light treatment.
Sunlight exposure helps the majority of people with psoriasis but must be used cautiously to avoid the risk of developing skin cancer.
TYPES OF TREATMENT
Excimer Laser - a carefully focused beam of laser light delivered through a sophisticated liquid light guide delivery system, the XTRAC system is designed to clear unsightly psoriatic skin plaques quickly and effectively. Because it concentrates light on active lesions, XTRAC allows your health care technician to deliver the high therapeutic doses necessary for rapid clearing without risk to healthy skin.
Narrowband UVB Light Therapy - Sunlight and ultraviolet light slow the rapid growth of skin cells. Psoriasis patients are directed to carefully sunbathe. People with psoriasis all over their bodies may require treatment with light boxes for full body exposure.
Biologic Drugs - Biologic drugs, or "biologics," are given by injection or intravenous (IV) infusion. A biologic is a protein-based drug derived from living cells cultured in a laboratory. While biologics have been used to treat disease for more than 100 years, the advent of modern day molecular biologic techniques has accelerated their use in modern day medicine tremendously in the last decade.
Different from the traditional systemic drugs that impact the entire immune system, biologics target specific parts of the immune system. The biologics used to treat psoriatic diseases act by blocking the action of a specific type of immune cell called a T cell, or by blocking proteins in the immune system, such as tumor necrosis factor-alpha (TNF-alpha) or interleukins 12 and 23. These cells and proteins all play a major role in developing psoriasis and psoriatic arthritis.
Steroids (Cortisone) - Cortisone creams, ointments, and lotions may help control the condition in many patients. Weaker preparations should be used on sensitive areas of the body. Stronger preparations will usually be needed to control lesions on the scalp, elbow, knees, palms and soles. These must be used cautiously and with specific instruction.
Side effects of the stronger cortisone preparations include thinning of the skin, dilated blood vessels, bruising, and skin color changes. Stopping these medications suddenly may result in a flare-up of the disease. After many months of treatment, the psoriasis may become resistant to the steroid preparations. Our providers may inject cortisone into difficult-to-treat spots.
Scalp Treatment - The treatment for psoriasis of the scalp depends on severity of the disease, hair length, and the patient's lifestyle. A variety of non-prescription and prescription shampoos, oils, solutions, and sprays are available. Most contain coal tar or cortisone.
Vitamin D - A synthetic Vitamin D, calcipotriene, is available in prescription form. It is useful for individuals with localized psoriasis and can be used with other treatments. Standard Vitamin D, bought in a drug store or health food store, is not proven to be of value in treating psoriasis.
Retinoids - Prescription vitamin A-related gels may be used alone or in combination with topical steroids for treatment of localized psoriasis.
Coal Tar - For more than l00 years, coal tar has been used to treat psoriasis. Today's products are greatly improved and less messy. Stronger prescriptions can be made to treat difficult areas.
PUVA - When psoriasis has not responded to other treatments especially on the hands and feet, PUVA is effective in 85 to 90 percent of cases. The treatment name comes from "Psoralen + UVA," the two factors involved. A topical preparation of the drug Psoralen is applied prior to treatment then the affected areas are exposed to a carefully measured amount of a special form of ultraviolet (UVA) light.
Light Therapies take approximately 25 treatments, over a two or three month period, before clearing usually occurs. About 30-40 treatments a year are usually required to keep the psoriasis under control. Over a long period light therapy increases the risk of skin aging and skin cancer. Beacuse of this, we monitor light treatments very carefully.
Methotrexate - an oral anti-cancer drug that can produce dramatic clearing of psoriasis when other treatments have failed. Because it can produce side effects, particularly liver disease, regular blood tests are performed. Chest x-rays and occasional liver biopsies may be required. Other side effects include upset stomach, nausea, and dizziness.
Cyclosporine - an immunosuppressant drug used to prevent rejection of transplanted organs (liver, kidneys). It is used for treatment of widespread psoriasis when other methods have failed. Because of potential effects on the kidneys and blood pressure, close medical monitoring is required together with regular blood tests.