Psoriasis is a chronic, non-curable, common relapsing and remitting immune mediated systemic disease characterized by red, scaly plaques. These skin lesions may vary in severity from localized patches to complete body coverage with nail and joint involvement (psoriatic arthritis).
The etiology of psoriasis is not fully understood. It is generally considered a genetic or inherited disease thought to be triggered or influenced by environmental factors. Psoriasis develops when the immune system mistakes a normal skin cell for a pathogen, and sends out faulty signals that cause overproduction of new skin cells. This over production of skin cells results in the thick, slivery plaque commonly seen. It is not contagious. It tends to flare during the winter. Stress, withdrawal of a systemic corticosteroid, a strep throat infection, and certain medications including beta-blockers, lithium, and anti-seizure medications have each been suggested as a trigger for psoriasis.Injury to the skin can trigger local psoriatic skin changes known as the Koebner phenomenon.
There are a number of treatment options for patients with psoriasis. The decision making process in treating a patient with psoriasis is multi factorial, and depends on the patient’s overall health, presence or absence of joint pain, and severity of the skin involvement. Topical and vitamin D analogues are prescribed in mild cases. In patients with more extensive disease, phototherapy (medically monitored and administered ultraviolet light) may be helpful. More recently, a class of drugs called biologic agents has transformed the treatment of severe psoriasis and psoriatic arthritis. These medications target specific inflammatory molecular markers involved in the disease process. The most commonly used biologics include: Etanercept, Adalimumab, Infliximab, and Usetekinumab. Immunosuppressive medications, like cyclosporine, oral retinoids, and anti-cancer drugs may also be effective in select cases. Newer anti-inflammatory mediations like Apremilast are also gaining momentum.