Psoriasis is a chronic, autoimmune skin condition. It is characterised by the rapid regeneration and accumulation of keratinocytes resulting in raised, red patches that become scaly. Normal keratinocytes, the keratin-producing cells found in the basal layer of the skin, move gradually to the surface of the epidermis where they will die and flake off. In people with psoriasis, this takes place over 3 to 7 days, whereas in normal skin it takes 3-4 weeks.
Plaque psoriasis is the most common form of the disease, typically affecting skin on the elbows, knees, low back and scalp. The patches that can crack and bleed may be painful and itchy. 3.2% of US adults, and 1.2% of youth under 18 have psoriasis. It is not commonly seen in children under 10.
An interesting 2013 study found that the rate of wound healing is increased in people with psoriasis. The study found that: “The N-methyl-D-aspartate (NMDA) receptor, an ionotropic glutamate receptor found on keratinocytes, is expressed abnormally in psoriasis in vivo.” This same study found that psoriasis involved an “increased vasodilation with local release of nitric oxide (NO) and skin infiltration by leukocytes.”
Genetic factors appear to play a role in psoriasis. A 2012 meta-analysis of genetic data of over 10,000 cases mentioned 36 susceptibility loci including one in the “major histocompatibility complex region on chromosome 6.”
While the etiology of psoriasis is unknown, like all autoimmune diseases it may be influenced by a wide range of stressors that can trigger immune dysfunction. These include Wounds, Emotional trauma, Infections, Genetic factors, Habits and lifestyle factors, and exposure to environmental Toxins. The mnemonic WEIGHT is a useful way to remember these potential stressors to identify the most likely contributors in each individual.
Human Genetic Material
LWP PH17 Skin
Skin & Connective Tissue