Causes of Psoriasis
Western Medicine View
There are various theories on the causes of psoriasis from the western medicine point. One theory with some evidence is that psoriasis can be inherited but there is much controversy over the mode of inheritance. The history of psoriasis in some families seem to suggest a simple autosomal inheritance with reduced penetrance, although evidence has been presented for multifactorial genetic components.
Note: Penetration is the frequency with which a mutant gene produces its characteristic effect in those invididual prossessing it.
Genetics Double Helix
There are also suggestion of link with human leucocyte antigen (HLA) phenotypes. The precise cause of psoriasis is not clear but the enhanced keratinocyte proliferation results in thickening of the epidermis. The augmented growth rate of the epidermis (or outer skin) is a result of an increased proportion of cycling cells recurited from the base epidermis rather than a chnge in the cell cycle time.
According to the autoimmune theory, psoriasis is a skin disorder driven by the immune system, especially involving a type of white blood cellcalled a T cell. Normally, T cells help protect the body against infection and disease. In the case of psoriasis, T cells are put into action by mistake and become so active that they trigger other immune responses, which lead to inflammation and to rapid turnover of skin cells.
Auto Immune Response
Chinese Medicine View
Chinese medicine blame the disease to deficiency of the blood, blockages of the flow of Qi, the food one consume and the emotional well being of a person. Combination of different type of causes will manifest itself in the pattern or appearance of psoriasis on the skin. For example, if the skin is itchy and red the cause is usually Wind and Heat; thick and purplish patches are likely to be due to Blood Stasis; Heat and Damp are indicated by red, weeping patches and if the patient feels tired easily and the patches are thick, pale and dry this is often due to a deficiency of blood and Qi.
Qi Meridians