Normal skin cells live about 28 days and then shed from the outer layer of skin. With psoriasis, the growth cycle is sped up and the body isn't able to shed the dead skin cells. As the dead skin cells build, patches of raised red skin covered by scaly, white flakes form. Psoriasis is a genetic disease but not contagious. Though there is no known cure or prevention, treatment focuses on minimizing the symptoms and healing affected areas.
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.
Types of Psoriasis
There are five distinct types of psoriasis.
Plaque Psoriasis (Psoriasis Vulgaris)
This form of psoriasis accounts for 80 percent of cases. Plaque psoriasis is typically found on the elbows, knees, lower back, and scalp. It appears as inflamed, red lesions covered by silvery-white scales.
Guttate psoriasis is most common in children and young adults. Small, red dot-like spots form on the limbs or torso, usually in response to an environmental trigger or health issue.
This type of psoriasis appears as bright red lesions that are smooth and shiny in appearance. Inverse psoriasis is usually found in the armpits, groin, in the skin around the genitals and buttocks, and under the breasts.
Pustular psoriasis can be localized or cover the body. White blisters, surrounded by red skin, appear to be pus-filled but are filled with white blood cells. Triggers may vary depending on the patient but can include contact allergens, infections, UV radiation exposure, and stress.
A highly inflamed and severe form of psoriasis, erythrodermic psoriasis features fiery red skin covering large areas of the body. Instead of flaking off the body, the skin sheds in white sheets. Severe itching and pain are associated with erythrodermic psoriasis and requires medical attention and treatment. Causes include abrupt withdrawal of systemic treatment, emotional stress, infection, and severe sunburn.
Patients with psoriasis have a higher risk of developing other health issues. The condition has been linked to a higher frequency of immune system-related conditions such as heart disease and hypertension. Triggers for psoriasis are specific to each patient but common triggers include diet, medication allergies, and skin injuries.
The severity of psoriasis impacts the choice of treatment. Mild to moderate psoriasis covers three percent to 10 percent of the body. Moderate to severe psoriasis covers more than 10 percent of the body.
Mild to Moderate Psoriasis
Mild to moderate psoriasis is generally treated at home using a combination of three strategies — over-the-counter medications, prescription topical treatments, and light therapy/phototherapy.
Two active ingredients with FDA-approval for treating psoriasis are salicylic acid and coal tar. Salicylic acid causes the outer layer of skin to shed. Coal tar slows the rapid growth of skin cells. Other common over-the-counter treatments include:
- Anti-itch preparations;
- Bath solutions, such as oiled oatmeal, Epsom salts or Dead Sea salts that remove scaling and relieve itching;
- Occlusion to improve absorption and effectiveness of topical medications; and
- Scale lifters that help loosen and remove scales to allow medications to reach the lesions.
Prescription Topical Treatments
Prescription topical treatments focus on slowing the growth of skin cells and reducing inflammation. Examples include:
- Anthralin: Used to reduce the growth of skin cells associated with plaque.
- Calcipotriene: Slows cell growth, flattens lesions and removes scales.
- Calcipotriene and Betamethasone Dipropionate: This treatment helps reduce the itch and inflammation along with slowing skin cell growth, flattening lesions, and removing scales.
- Calcitriol: This is an active form of vitamin D3 that helps control excessive skin cell production.
- Tazarotene: A topical retinoid used to slow skin cell growth.
- Topical steroids: The most commonly prescribed medication for psoriasis, topical steroids fight inflammation and reduce lesion swelling and redness.
Some forms of psoriasis can be successfully treated by using controlled skin exposure to ultraviolet light. Three primary light sources used are:
- Sunshine (both UVA and UVB rays): Sunshine can help ease the symptoms of psoriasis. But, sunlight exposure requires careful monitoring to make sure no other skin damage occurs. It's recommended sunshine be used in controlled, short bursts.
- Excimer lasers: These devices target specific areas of psoriasis. The laser emits a high-intensity beam of UVB directly onto the psoriasis plaque. Between four treatments and 10 treatments are needed to see an improvement.
- Pulse dye lasers: This treatment uses a wavelength of UVB light to treat smaller areas of psoriasis. Pulse dye lasers destroy the blood vessels that contribute to lesion formation. Generally, four sessions to six sessions are necessary to clear up a small area.