Psoriasis is a persistent skin disorder in which there are red, thickened areas with silvery scales, most often on the scalp, elbows, knees, and lower back. Some cases, of psoriasis are so mild that people don't know they have it. Severe psoriasis may cover large areas of the body. Psoriasis is not contagious and cannot be passed from one person to another, but it is most likely to occur in members of the same family. Two to three percent of North Americans are affected by the condition
The cause is unknown. However, studies recently done have discovered that there may be a special white cell that may trigger the inflammation that occurs. This results in an abnormality which sets off the immune response of the skin, causing it to grow too fast. Generally, the skin will replace itself in about 30 days, but in psoriasis, the process speeds up and replaces the skin in three to four days, and patients develop the signs of psoriasis (thickness and scaling).
Patients often find new patches around10 and 14 days after a severe sunburn (the Koebner Phenomenon), or when the skin is rubbed, scratched, or cut. Psoriasis may also be aggravated by infections, including strep throat, or by certain medicines (lithium, beta blockers, etc.) Flare-ups may occur in the winter, as a result of dry skin and lack of sunlight.
TYPES OF PSORIASIS
Psoriasis comes in many forms. Each differs in severity, duration, location, shape, and pattern of the scales. The most common form, called plaque psoriasis, begins with little red bumps. Gradually, these become larger, and scales form. While the top scales flake off easily and often, scales below the surface stick together. These small red areas can enlarge.
- Scalp, elbows, arms, palms, knees, legs, soles of the feet, nails, and genitals, are the areas of the body most commonly affected by psoriasis. It will often appear in the same place on both sides of the body.
- Scalp psoriasis can be confused with dandruff.
- When nails are affected by psoriasis they frequently have tiny pits in them. Nails may loosen, thicken, or crumble, and are difficult to treat.
- Inverse psoriasis occurs in the armpit, under the breasts, and in skin folds around the groin, buttocks, and genitals. This form responds very well to treatment.
- Guttate psoriasis usually affects children and young adults. It often starts after a sore throat with many small, red, scaly spots appearing on the skin. It frequently clears up by itself within a few weeks or months.
- Up to 30% of people with psoriasis may have symptoms of arthritis and 5-10% may have some functional disability from arthritis.
Dermatologists diagnose psoriasis by examining the skin, nails, and scalp. If the diagnosis is in doubt, a skin biopsy may be helpful.
The goal is to reduce inflammation and to control the shedding skin. Creams can moisturize the skin and loosen the scales while helping to control itching. Specialized diets are not a successful way to treat psoriasis, except in a few isolated cases.
Treatment is based on a patient's health, age, lifestyle, and the severity of the psoriasis. Different types of treatments and several visits to your dermatologist may be needed.
Your dermatologist can prescribe topical medications containing synthetic vitamin D analogues (Dovonex), cortisone compounds, combination products (Dovobet), topical immunomodulatory creams (Tacrolimus, Pimecrolimus), retinoids (vitamin A derivative), and tar. These may be used in combination with natural sunlight or ultraviolet light. The more severe forms of psoriasis may require oral or injectable medications with or without light treatment. Sunlight exposure helps the majority of people with psoriasis although it must be used with caution. Ultraviolet light (UV) therapy can be provided in a dermatologist's office or a hospital.
TYPES OF TREATMENT
- Biologic Agents - Alefacept (Amevive), Etanercept (Enbrel), Infliximab (Remicaide), Ustekinumab (Stelara) and Adalimumab (Humira) are new agents with varying degrees of efficacy for psoriasis and psoriatic arthritis, and are either administered by self-injection or intravenously. Because of their high-cost, third party insurance is often required. Speak with your dermatologist as to the best option for you.
- Clinical Trial agents - At Dermatology on Bloor, we participate in many clinical trials to help bring new and more effective treatments to market for the aid of patients affected by Psoriasis and other skin disease. If you would be interested in being involved in a clinical trial, contact Research Coordinator Roxana at (416) 962-0123 we will be happy to discuss with you whether this is an option that would be right for you.
- Light Therapy - Sunlight and ultraviolet light slow the rapid growth of skin cells. Although UV light or sunlight can result in skin wrinkling, skin cancer, and eye damage the light treatment is safe and effective under a doctor's care.
- Methotrexate - This is an oral anti-cancer drug that can produce dramatic clearing of psoriasis when other treatments have failed; it is also useful in psoriatic arthritis. Because it can cause side effects, particularly liver disease, regular blood tests are performed. Other side effects include upset stomach, dizziness, and nausea. Methotrexate should not be used by pregnant women, or by men and women who are trying to conceive a child. Patients taking methotrexate should not consume alcohol.
- Retinoids - Prescription oral vitamin A-related drugs (e.g. Soriatane, Clams Accutane) may be prescribed alone or in combination with UV light for severe cases of psoriasis. The side effects can include dry skin, lips, and eyes, and elevation of fat levels in the blood (cholesterol and triglycerides). Oral retinoids are not commonly used in women of child-bearing age. Occasional blood tests are required
- Steroids (Cortisone) - Cortisone is a medication your dermatologist may prescribe to reduce the inflammation. Cortisone creams, lotions, and ointments may clear the skin temporarily and control the condition in many patients. Weaker preparations should be used on more sensitive areas of the body such as the face and genitals. Stronger forms will typically be needed to control lesions on the scalp, palms, elbows, knees, parts of the torso, and soles of the feet. Side effects related to the stronger cortisone preparations when misused can include dilated blood vessels, thinning of the skin, skin color changes, and bruising. Stopping these medications suddenly may result in a flare-up of the disease. Occasionally, the psoriasis may become resistant to the steroid preparations. Your dermatologist may inject cortisone in difficult-to-treat spots.
We put academic qualifications, many years of combined experience, and training in a variety of special interest areas to work for your healthy, radiant skin. Our providers – Drs. Schachter, Hanna, Curtis, Abdulla, Pollack, and Taradash – welcome new patients for treatment at the Dermatology on Bloor practice on Park Road in Toronto. Our team is here to serve your needs