The actual cause of psoriasis is not known. What is known is that the condition tends to run in families and rarely strikes until the mid teens or early adulthood.
Psoriasis is the result of an overproduction of skin cells. Research is still continuing into the cause of this overproduction however common factors that trigger a flareup of the condition are well known and it is often controlling these triggers that will help to control the condition.
Where the cell went wrong!
To understand psoriasis and where the psoriatic cell has gone wrong we first must understand the formation of the normal cell. The initial cell formation of the skin starts in the basal layer or at the base of the skin.
Once formed the cell makes its way to the epidermis or skin surface where it sloughs off and is replaced by new skin cells forming below. In the normal cell this entire process from production, growth and gradual hardening to shedding takes approximately one month.
Goes through the process in 4 days
The psoriatic cell on the other hand goes through this entire process in less than four days. So from developing in the skin’s basal layer to being shed on the skin’s epidermis it has insufficient time to form properly, or pass through the normal process of skin maturation and keratinization.
Keratinization is the process by which the insoluble, fibrous structure of the skin is formed. This produces a build up of dead cells on the surface of the skin commonly known as the scales of psoriasis.
The end result is the formation of thick scaly plaques which do not provide the skin with its usual protective layers. If the silvery scales are scraped away the dark red base of the lesion is exposed resulting in multiple bleeding points.
This is because the outer cells of the skin which provide it with its protective layer are non living and do not have a blood supply. However the underlying skin layers have a blood supply and will bleed when exposed.
So why does psoriasis only affect some people?
The underlying cause is unknown. However, it can be genetically inherited or passed from generation to generation. Initial lesions tend to form in areas of skin trauma (i.e. sunburn or streptococcal infection).
These areas are believed to be “trigger” points in people with a genetic predisposition. Having said this it must be understood that psoriasis is not an infection and it is not contagious.