A chronic disease of the skin consisting of itchy, dry, red patches, usually affecting the scalp or arms and legs. A common chronic skin disease, more common in whites (2% of the population) than in other racial groups, in which red flaky lesions occur often on the elbows and knees, or in the scalp. May cause nail abnormalities. A chronic skin disease that occurs when cells in the outer layer of the skin reproduce faster than normal and pile up on the skin's surface. This results in scaling and inflammation. An estimated 10 to 30 percent of people with psoriasis develop an associated arthritis called psoriatic arthritis.

More than 4.5 million adults in the United States have been diagnosed with psoriasis, and approximately 150,000 new cases are diagnosed each year. An estimated 20% have moderate to severe psoriasis.

Causes of Psoriasis
The cause of psoriasis is not known, but it is believed to have a genetic component. Several factors are thought to aggravate psoriasis. These include stress, excessive alcohol consumption, and smoking. Individuals with psoriasis may suffer from depression and loss of self-esteem. When psoriasis develops, patches of skin thicken, redden, and become covered with silvery scales; these patches are also known as plaques.

Types of Psoriasis
Plaque psoriasis (psoriasis vulgaris) - is the most common form of psoriasis. It affects 80 to 90% of people with psoriasis.
Flexural psoriasis appears as smooth inflamed patches of skin. It occurs in skin folds, particularly around the genitals (between the thigh and groin), the armpits, under an overweight stomach (pannus), and under the breasts (inframammary fold).
Guttate psoriasis is characterized by numerous small oval spots. These numerous spots of psoriasis appear over large areas of the body, such as the trunk, limbs, and scalp.
Pustular psoriasis appears as raised bumps that are filled with non-infectious pus (pustules). The skin under and surrounding pustules is red and tender.
Nail psoriasis produces a variety of changes in the appearance of finger and toe nails.
Treatment of Psoriasis
There can be substantial variation between individuals in the effectiveness of specific psoriasis treatments. Because of this, dermatologists often use a trial-and-error approach to finding the most appropriate treatment for their patient. It has long been recognized that daily, short, non-burning exposure to sunlight helped to clear or improve psoriasis. Climatotherapy involves the notion that some diseases can be successfully treated by living in a particular climate. Several psoriasis clinics are located throughout the world based on this idea.

According to supporters of Ayurvedic medicine, managing disease and restoring health involve assessing the whole person to understand the nature of the imbalance. For psoriasis, a specific treatment regimen might involve topical application of certain oils, such as sesame or mustard; fasting and other dietary guidelines; elimination of stress; and regular physical exercise.

Naturopathic practice excludes major surgery and the use of most synthetic drugs. Naturopathic treatments can complement those used by conventionally trained doctors. How a naturopathic doctor treats psoriasis varies from practitioner to practitioner.

Herbal remedies are increasingly popular and mainstream. Many people dealing with chronic diseases such as psoriasis turn to these alternatives when Western medicine stops working.