Psoriasis is a skin disease that occurs when cells in the outer layer of skin reproduce faster than normal and pile up on the skin's surface. This produces scaling, itchiness and irritation of the skin. Psoriasis is non-contagious.
Currently in the United States almost 5 million people are affected by this disease. It occurs in all age groups and about equally in men and women.
When psoriasis develops, thick patches of skin become red with silvery scales. Often the skin at the joints cracks making outbreak very painful. Psoriasis most often occurs on the knees, lower back, soles of the feet, scalp, elbows, face and palm.
There have been huge strides in understanding what causes psoriasis. Recently, a team from the University of Michigan looked for the gene -- called PSORS1 -- in more than 2,700 people from 678 families in which at least one family member had psoriasis. According to the researchers, PSORS1 is the first genetic determinant of psoriasis to be definitively identified in a large clinical trial. The finding may help in the development of new, more effective treatments for the disfiguring inflammatory skin disease.
Some other research has found that psoriasis may be a disorder of the immune system. In a normal immune system a type of white blood cell, called a T cell is produced, that normally helps protect the body against infection and disease. Top Scientists have concluded that an abnormal immune system produces too many T cells in the skin. These excess T cells trigger the inflammation and excessive skin cell reproduction seen in people who suffer with psoriasis.
Doctors usually diagnose psoriasis after a careful examination of the skin. However, diagnosis may be difficult because psoriasis often looks like other skin diseases. A pathologist may assist with diagnosis by examining a small skin sample under a microscope.
What’s the difference between eczema and atopic dermatitis?
Eczema is a general term encompassing various inflamed skin conditions. One of the most common forms of eczema is atopic dermatitis (or "atopic eczema"). Approximately 10 percent to 20 percent of the world population is affected by this chronic, relapsing, and very itchy rash at some point during childhood. Fortunately, many children with eczema find that the disease clears and often disappears with age.
In general, atopic dermatitis will come and go, often based on external factors. Although its cause is unknown, the condition appears to be an abnormal response of the body’s immune system. In people with eczema, the inflammatory response to irritating substances overacts, causing itching and scratching. Eczema is not contagious and, like many diseases, currently cannot be cured. However, for most patients the condition may be managed well with treatment and avoidance of triggers.
What does eczema look and feel like?
Although eczema may look different from person to person, it is most often characterized by dry, red, extremely itchy patches on the skin. Eczema is sometimes referred to as "the itch that rashes," since the itch, when scratched, results in the appearance of the rash.
Eczema can occur on just about any part of the body; however, in infants, eczema typically occurs on the forehead, cheeks, forearms, legs, scalp, and neck. In children and adults, eczema typically occurs on the face, neck, and the insides of the elbows, knees, and ankles. In some people, eczema may "bubble up" and ooze. In others, the condition may appear more scaly, dry, and red. Chronic scratching causes the skin to take on a leathery texture because the skin thickens (lichenification).