Psoriasis

Psoriasis is a common visible skin disease, characterized by chronic inflammatory lesions with red, scaling plaques. The cause of psoriasis is not known for certain although there are many factors that can cause it to start appearing. Psoriasis is considered a skin disease, but it is believed to be an autoimmune phenomenon. Psoriasis has been widely accepted as a disease mediated by the immune system since 1979. Two decades of intensive research followed, as researchers sought to understand exactly what happened within the immune system to cause skin cells to proliferate too quickly—the underlying problem of psoriasis. The exact chain of events is still not completely understood. However, significant progress has been made in unraveling the immunology involved with psoriasis. The T cells, a type of white blood cell, become over-stimulated and once activated, these cells release "cytokines," which are chemicals used by the immune system to communicate messages that direct the skin to try and “heal” a non-existent injury. The skin reacts by growing very fast, trying to grow over the "infected" area which results in the subsequent thickening of the epidermis. Keratinocytes proliferate and stimulate endothelial cell activation, which in turn exacerbates inflammation.