Causes

Psoriasis is a condition which runs in families, i.e. it is genetically determined, but the exact way in which the disease moves from generation to generation has not yet been confirmed. However, exposure to certain factors, such as a streptococcal infection in the throat, alcohol, medicines or local irritation or damage to the skin, may cause a burst of psoriasis in persons who have this genetic predisposition.

The cause of psoriasis is not fully understood. There are two main hypotheses about the process that occurs in the development of the disease. The first considers psoriasis as primarily a disorder of excessive growth and reproduction of skin cells. The problem is simply seen as a fault of the epidermis and its keratinocytes.

The second hypothesis suggests that psoriasis is driven by an immune-mediated disorder n which the excessive reproduction of skin cells is secondary to factors. called a T cells (white blood cells which normally protect the body against infection) become active, migrate to the dermis and trigger the release of cytokines (tumor necrosis factor-alpha TNF_, in particular) which cause inflammation and the rapid production of skin cells. These cells pile up on the surface of the skin, forming itchy patches or plaques.

The first outbreak of psoriasis is often triggered by emotional or mental stress or physical skin injury, but heredity is a major factor as well. In about one-third of the cases, there is a family history of psoriasis. Researchers have studied a large number of families affected by psoriasis and identified genes linked to the disease. (Genes govern every bodily function and determine the inherited traits passed from parent to child.)

Psoriasis is a fairly peculiar disease. The majority of people's experience of psoriasis is one in which it may worsen or improve for no apparent reason. Nevertheless, the first outbreak is sometimes reported following stress (physical and mental), skin injury, and streptococcal infection. Conditions that have been reported as accompanying a worsening of the disease include infections, stress, and changes in season and climate. Certain medicines, including lithium salt and beta blockers, have been reported to trigger or aggravate the disease. Excessive alcohol consumption, smoking and obesity may exacerbate psoriasis or make the management of the condition difficult.

A diagnosis of psoriasis is usually based on the appearance of the skin. There are no custom blood tests or diagnostic procedures for psoriasis. Sometimes a skin biopsy, or scraping, may be needed to rule out other disorders and to confirm the diagnosis. Skin from a biopsy will show clubbed Rete pegs if positive for psoriasis. Another sign of psoriasis is that when the plaques are scraped, one can see pinpoint bleeding from the skin below (Auspitz's sign).

Psoriasis is a chronic, meaning lifelong, condition due to the fact that there is currently no cure but various treatments can help ease patient's condition. People often experience flares and remissions throughout their life. Controlling the signs and symptoms typically requires lifelong therapy.

Psoriasis occurs more likely in dry skin than oily or well-moisturized skin, and specifically after an external skin injury such as a scratch or cut. This is believed to be caused by an infection, in which the infecting organism thrives under dry skin conditions with minimal skin oil, which otherwise protects skin from infections. To prevent dry skin and reduce psoriasis symptoms, it is advised to not use shower scrubs, as they not only damage skin by leaving tiny scratches, they also scrape off the naturally occurring skin oil. Additionally, moisturizers can be applied to moisturize the skin, and lotions used to promote skin oil gland functions.

Psoriasis sometimes has an emotional impact on people's feelings, behaviors and experiences. Psoriatic arthritis for example causes frustration and can make simple daily activities more difficult. Many people affected by psoriasis suffer from social exclusion and discrimination. Because of the skins lesions patients may feel sadness, despair, guilt, anger and low self-esteem. A person's sense of self-worth can be affected and, in some cases, the emotional turmoil of psoriasis can lead to depression.

The phrase "the heartbreak of psoriasis" is often used to describe the emotional impact of the disease. It may include both the effect of having a chronic uncomfortable disorder and the social effects of being self conscious of one's appearance.