Psoriasis is a complex, inflammatory disease which mostly affects the skin and joints. It is however not a contagious disease.
The disease affects both males and females of all age groups. Nevertheless it mostly makes its mark for the first time in young individuals between the ages of 15-20 years. It is quite unusual for the disease to manifest before the age of 5 years.
This disease is common, chronic, and costly, both in monetary terms and in quality of life. According to a study in India, 60% of the patients had the disease onset before the age of 30 years, with a positive family history in almost 14% of the cases. Skin and scalp was the most commonly affected site.
How is it caused?
The pathogenesis of psoriasis is yet unknown but it is believed to be immune-mediated. Genes also play a role in its development.
The inheritance of psoriasis does not fit into the Mendelian pattern. When one parent has the disease the chances of the child to develop the disease is 15-20%; if both parents have the disease, the chances of the child getting the disease is 50 percent.
Plaque psoriasis or psoriasis vulgaris is the most common form of the disease. There are typically, red scaly patches – called psoriatic plaques that appear on the skin of affected persons. These plaques are inflammatory sites where the skin rapidly accumulates, thereby, taking on a silvery white appearance. When the scales are removed, the skin underneath is tender and tends to bleed and results in the inflamed patches.
In the case of a normal skin, the production and proliferation of the epidermal layer of the skin takes about 28 days to complete, while in the case of psoriasis, it is restricted to just 4 days. This results in the pile up of immature skin cells – a special feature characteristic to psoriatic lesion.