Psoriasis is a skin condition that creates red patches of skin with white, flaky scales. It most commonly occurs on the elbows, knees and trunk, but can appear anywhere on the body. The first episode usually strikes between the ages of 15 and 35. It is a chronic condition that will then cycle through flare-ups and remissions throughout the rest of the patient's life. Psoriasis affects as many as 7.5 million people in the United States. About 20,000 children under age 10 have been diagnosed with psoriasis.
In normal skin, skin cells live for about 28 days and then are shed from the outermost layer of the skin. With psoriasis, the immune system sends a faulty signal which speeds up the growth cycle of skin cells. Skin cells mature in a matter of 3 to 6 days. The pace is so rapid that the body is unable to shed the dead cells, and patches of raised red skin covered by scaly, white flakes form on the skin.
Psoriasis is a genetic disease (it runs in families), but is not contagious. There is no known cure or method of prevention. Treatment aims to minimize the symptoms and speed healing.
Because psoriasis is chronic, anyone with the condition will live with a cycle of flare-ups and remissions over a lifetime. Typically, patients with psoriasis may develop initial symptoms or experience flare ups because of various triggers, including
- Certain medications
- Cuts, scrapes, burns, or other damage to the skin
- Excessive alcohol use
- Other infections such as strep throat
Types of Psoriasis
There are six main types of psoriasis:
- Plaque Psoriasis (Psoriasis Vulgaris) About 80 percent of people diagnosed with the disease have plaque psoriasis, or psoriasis vulgaris. Plaque psoriasis often appears as on the elbows, knees, and lower trunk in the form of raised, red lesions topped with silvery scales.
- Guttate Psoriasis Usually found on the limbs or trunk, guttate psoriasis primarily appears in patients younger than age 30. Guttate psoriasis presents as small, water-drop-shaped sores and can occur because of an illness or injury to the skin.
- Inverse Psoriasis With inverse psoriasis, patients develop smooth, shiny lesions that are bright red in color. Most often seen in people who are overweight, inverse psoriasis strikes the armpits, around the genitals, near the groin, and under the breasts.
- Pustular Psoriasis When you have pustular psoriasis, white blisters filled with pus and surrounded by red skin will appear either in localized areas or all over your body. Because the pus is made of white blood cells, it is not contagious. Certain things can trigger pustular psoriasis, such as irritating topical treatments, infections, overexposure to ultraviolet radiation, and stress.
- Erythrodermic Psoriasis Characterized by a fiery red rash coupled with extreme burning or itching, erythrodermic psoriasis is the least common kind of psoriasis. Triggers for erythrodermic psoriasis include severe sunburn, corticosteroids, other medications, or another type of psoriasis that has flared up.
- Psoriatic Arthritis In addition to causing pitted, discolored nails, psoriatic arthritis also presents with the swollen, painful joints that often accompany arthritis. Usually psoriatic arthritis isn't as crippling as other forms of arthritis, but it can cause stiffness and progressive joint damage.
Psoriasis is classified as Mild to Moderate when it covers 3% to 10% of the body and Moderate to Severe when it covers more than 10% of the body. The severity of the disease impacts the choice of treatments.
Mild to Moderate Psoriasis
Mild to moderate psoriasis can generally be treated at home using a combination of three key strategies: over-the-counter medications, prescription topical treatments and light therapy/phototherapy.
The U.S. Food and Drug Administration has approved of two active ingredients for the treatment of psoriasis: salicylic acid, which works by causing the outer layer to shed, and coal tar, which slows the rapid growth of cells. Other over-the-counter treatments include:
- Scale lifters that help loosen and remove scales so that medicine can reach the lesions.
- Bath solutions, like oilated oatmeal, Epsom salts or Dead Sea salts that remove scaling and relieve itching.
- Occlusion, in which areas where topical treatments have been applied are covered to improve absorption and effectiveness.
- Anti-itch preparations, such as calamine lotion or hydrocortisone creams.
- Moisturizers designed to keep the skin lubricated, reduce redness and itchiness and promote healing.
Prescription Topical Treatments
Prescription topicals focus on slowing down the growth of skin cells and reducing any inflammation. They include:
- Anthralin, used to reduce the growth of skin cells associated with plaque.
- Calcipotriene, that slows cell growth, flattens lesions and removes scales. It is also used to treat psoriasis of the scalp and nails.
- Calcipotriene and Betamethasone Dipropionate. In addition to slowing down cell growth, flattening lesions and removing scales, this treatment helps reduce the itch and inflammation associated with psoriasis.
- Calcitriol, an active form of vitamin D3 that helps control excessive skin cell production.
- Tazarotene, a topical retinoid used to slow cell growth.
- Topical steroids, the most commonly prescribed medication for treating psoriasis. Topical steroids fight inflammation and reduce the swelling and redness of lesions.
Controlled exposure of skin to ultraviolet light has been a successful treatment for some forms of psoriasis. Three primary light sources are used:
- Sunshine (both UVA and UVB rays). Sunshine can help alleviate the symptoms of psoriasis, but must be used with careful monitoring to ensure that no other skin damage takes place. It is advised that exposure to sunshine be in controlled, short bursts.
- Excimer lasers These devices are used to target specific areas of psoriasis. The laser emits a high-intensity beam of UVB directly onto the psoriasis plaque. It generally takes between 4 and 10 treatments to see a tangible improvement.
- Pulse dye lasers. Similar to the excimer laser, a pulse dye laser uses a different wavelength of UVB light. In addition to treating smaller areas of psoriasis, it destroys the blood vessels that contribute to the formation of lesions. It generally takes about 4 to 6 sessions to clear up a small area with a lesion.
Moderate to Severe Psoriasis
Treatments for moderate to severe psoriasis include prescription medications, biologics and light therapy/phototherapy.
Oral medications This includes acitretin, cyclosporine and methotrexate. Your doctor will recommend the best oral medication based on the location, type and severity of your condition.
Biologics Generally reserved for the most severe cases of psoriasis, biologics are a new class of injectable drugs that suppress the immune system. Biologics tend to be expensive and have various side effects.
Light Therapy/Phototherapy Controlled exposure of skin to ultraviolet light has been a successful treatment for some forms of psoriasis. Two primary light sources are used:
- Ultraviolet light In certain cases, exposure of the skin to ultraviolet light can help control psoriasis. Both the UVA and UVB rays from sun light can alleviate the symptoms of psoriasis but the exposure should be in short, controlled sessions.
- PUVA. This treatment combines a photosensitizing drug (psoralens) with UVA light exposure. This treatment takes several weeks to produce the desired result. In some severe cases, phototherapy using UVB light may lead to better results.