Medical Dermatology - Psoriasis
Psoriasis is a chronic disease of the immune system that appears on the skin, usually in the form of thick, red, scaly patches. Up to 30 percent of people with psoriasis also develop psoriatic arthritis. Psoriasis is associated with other serious conditions such as diabetes, heart disease and obesity. According to the National Institutes of Health, as many as 7.5 million Americans have psoriasis.
There are five types of psoriasis:
The most common form, plaque psoriasis, appears as raised, red patches or lesions covered with a silvery white buildup of dead skin cells, called scale. Psoriasis can occur on any part of the body and is associated with other serious health conditions, such as diabetes, heart disease and depression.
No one knows exactly what causes psoriasis. However, it is understood that the immune system and genetics play major roles in its development. Most researchers agree that the immune system is somehow mistakenly triggered, which causes a series of events, including acceleration of 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 falling off (shedding), the cells pile up on the surface of the skin, forming psoriasis lesions.
Psoriasis triggers are not universal. What may cause one person’s psoriasis to become active, may not affect another. Established psoriasis triggers include:
- Injury to skin
Although scientifically unproven, some people with psoriasis suspect that allergies, diet and weather trigger their psoriasis. Strep infection is known to trigger guttate psoriasis.
A combination of dry air, decreased sunlight exposure, and colder temperatures can all contribute to winter psoriasis flares. Frequent moisturizing and use of a home humidifier can help alleviate some of the symptoms. Discuss with your doctor possible treatments to control your psoriasis in the winter.