Health is a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity.
World Health Organization
Edited by Nicole Day, MS, MBA
Guyana Journal, July 2009
What is Psoriasis?
Psoriasis is a chronic autoimmune disease (this means that the body's tissues are attacked by its own immune system) that appears on the skin for which there is currently no cure. It occurs when the immune system sends out faulty signals that speed up the growth cycle of skin cells. In the United States, approximately 7.5 million people, or 2.2 % of the population, have psoriasis. Worldwide, 125 million people or 2 to 3 % of the total population have psoriasis. Psoriasis often appears between the ages of 15 and 25, but can develop at any age. Psoriasis can vary from mild disease, in which a person has isolated patches, to severe disease, in which lesions (patches) cover most of the body. In some cases, fingernails and toenails are affected, which can cause pitting of the nail or may lead to the nail lifting or crumbling. Depending on its severity, psoriasis can be a minor irritation of the skin or it can be painful and disabling.
What are the Causes of Psoriasis?
Psoriasis is not contagious and is not transmitted through contact of any kind. The exact cause of psoriasis is unknown, but it is believed that a combination of several factors, including the immune system and genetics, contribute to the development of the disease. Most researchers agree that the immune system is mistakenly triggered, which causes a series of events, including rapid skin cell growth. A normal skin cell matures and falls off the body in 28 to 30 days. A skin cell in a patient with psoriasis takes only 3 to 4 days to mature and, instead of shedding, the cells pile up on the surface of the skin, forming psoriasis lesions.
About 1 out of 3 people with psoriasis have a relative with psoriasis. If a parent has psoriasis, a child has about a 10% chance of having psoriasis, but if both parents have psoriasis, a child has approximately a 50% chance of developing the disease. Researchers believe that at least 10% of the population has one or more of the genes that create a predisposition to psoriasis. However, only 2% to 3% of the population develops the disease. Thus, it is thought that for a person to develop psoriasis, the individual must have a combination of the genes that cause psoriasis and also be exposed to specific external (outside) factors.
What are the Symptoms of Psoriasis?
There are five types of psoriasis, each with unique signs and symptoms:
o Plaque psoriasis is the most common form of the disease, affecting approximately 80% of psoriasis patients. Also known as “psoriasis vulgaris”, plaque psoriasis is characterized by red, raised, itchy patches of skin that vary in diameter from coin-sized to palm-sized or even larger. These patches are usually round or oval in shape, but can be irregular in shape, and are covered by silvery white scales. They are typically found on the elbows, knees, scalp and lower back.
o Guttate psoriasis is a form of psoriasis that often starts in childhood or young adulthood and accounts for nearly 18% of psoriasis cases. Guttate psoriasis appears as numerous small, droplet-shaped spots and patches ranging in diameter from 0.1 cm to 1.0 cm. Guttate lesions usually appear on the trunk and limbs. These spots are not usually as thick as plaque lesions.
o Inverse psoriasis is found in the armpits, groin, under the breasts, and in other skin folds around the genitals and the buttocks. This type of psoriasis appears as bright-red lesions that are smooth and shiny. Inverse psoriasis is subject to irritation from rubbing and sweating because of its location in skin folds and tender areas. It can be more troublesome in overweight people and those with deep skin folds.
o Pustular psoriasis is primarily seen in adults and is characterized by pus-filled blisters on the skin. Pustular psoriasis may be localized to certain areas of the body, such as the hands and feet, or covering most of the body. The blisters tend to dry up in a few days, but may reappear every few days or weeks. This type of psoriasis is more common in women than men and accounts for less than 2% of cases.
o Erythrodermic psoriasis is a particularly inflammatory form of psoriasis that affects most of the body surface. Rather than the distinct red patches that are seen with other types of psoriasis, this type of the disease causes large areas of the skin to become red and scaly. The reddening and shedding of the skin are often accompanied by severe itching and pain, heart rate increase, and fluctuating body temperature.
How is Psoriasis Treated?
Psoriasis treatments aim not only to remove scales and smooth the skin, but also ultimately to interrupt the cycle that causes an increased production of skin cells, thereby reducing inflammation and plaque formation.
Psoriasis treatments include topical treatments, phototherapy (or light therapy), and oral and injected medications. Physicians select a treatment based on the type of psoriasis, severity of the disease, and the areas of skin affected. Typically a physician will begin with the mildest treatments, topical creams and phototherapy, and then progress to stronger treatments if necessary. The goal is to find the most effective way to slow cell turnover with the fewest possible side effects.
For further information on psoriasis, please visit the National Psoriasis Foundation website at www.psoriasis .org, email firstname.lastname@example.org, or call 503.244.7404 or 800.723.9166.
Nicole Day is a Senior Content Development Specialist in Horsham, PA.