Psoriasis and atopic eczema are the most common chronic inflammatory skin diseases affecting a large number of patients worldwide. Both diseases have a substantial negative impact on the patients' quality of life.
Psoriasis is a noncontagious, lifelong skin disease. According to the National Institutes of Health, as many as 7.5 million Americans have psoriasis. In Sweden around 3% of people suffer from psoriasis. It usually causes red scaly patches on the skin. The scaly patches caused by psoriasis, called psoriatic plaques, which are areas of inflammation and excessive skin production. Skin rapidly accumulates at the sites and has a silvery-white appearance. Plaques mainly occur on the skin of the elbows and knees, but can affect any area such as scalp and genitals.
Psoriasis can also cause inflammation of the joints, which is known as psoriatic arthritis. Up to 30 percent of people with psoriasis also develop psoriatic arthritis, which causes pain and swelling in and around the joints. Early diagnosis and treatment of psoriatic arthritis can considerably relieve pain and inflammation.
Immune system and psoriasis
In psoriasis immune cells antigen presenting cells such as DCs and also some T cells produce the key inflammatory molecules such as tumor necrosis factor (TNF), which plays a role in almost all psoriasis symptoms such as inflammation, redness, pain, and itching in the plaques. It can make blood vessels multiply, and white cells move from the blood vessels into the skin. This may explain why patients bleed so easily when they scratch the plaques. DCs can also produce and release the cytokine IL-23, which stimulates a group of CD4+ Th cells, Th17 cells, to produce the key pathogenic cytokines, IL-17 and IL-22, in the psoriatic lesions. In addition to the Th17 cells, antigen presenting cells-derived IL-12 can also mediate differentiation of CD4+ Th cells towards Th1 cells, which can produce TNF and IFN-gamma. All the mentioned cytokines have been shown to be involved in the pathogenesis of psoriasis. IL-17, IL-23 and IFN-gamma can activate the keratinocytes, and these cells in turn will release proinflammatory cytokines such as IL-8 and other factors, which play a role in inflammatory responses.
Posts
It is very intresanta description of this disease. But it is a pity that it has so far not found specific treatment of this disease. I wonder can this disease be inherited?
ReplyDeleteThanks for your comments. There have been several reports demonstrating that genetic factors such as human leukocyte antigen (HLA)-Cw6 are associted with psoriasis. Thus, the incidence of psoriasis can be increased in people, whose parents have psoriasis.
ReplyDelete