Psoriasis is a chronic, inflammatory, multisystemic disease that affects approximately 2 percent of the U.S. population. It shows up as pink or red scaly plaques. There may be a few coin-shaped lesions on the elbows and knees, or it may affect the entire skin surface.
This recurrent skin disease changes the life cycle of skin cells, causing them to build up quickly on the surface of the skin. Sites affected generally include the scalp, nails, fronts of the forearms, belly button region and lower-back/tailbone area. The eruption is typically symmetrical. Eventually, the skin lesions may clear, though the normal pigment of the skin may become lighter or darker than it was before.
Common symptoms of psoriasis include burning and itching of the skin lesions, which can be quite severe. Psoriasis evolves slowly; however, there is a guttate form, which is the sudden development of gumdrop-like lesions typically related to the beta-hemolytic strep bacteria manifesting as either a sore throat or as a red rash around the anus. This subtype is more common in children.
Most types of psoriasis go through cycles, flaring up for a few weeks or months, then remitting for some time or even going into complete remission. Psoriatic arthritis occurs in approximately a quarter of patients with cutaneous psoriasis. A classic presentation of this is when there is inflammation, redness and swelling of the small joints of the hands classically described as a “sausage digit.” This can be quite painful.
Onset of Psoriasis
There are usually two peaks of onset of psoriasis — one at 20 to 30 years of age and the other at 50 to 60 years of age. In approximately 75 percent of patients, the onset is before the age of 40.
Genetic factors also play a role in the clinical course of the disease. It is common for psoriasis to occur in increased frequency among family members. PSORS1 is considered the major gene involved in up to half of patients with psoriasis.
Both internal and external triggering factors can bring forth psoriasis in genetically predisposed individuals. External factors that flare psoriasis include trauma to the skin, such as sunburn. Internal or systemic factors include infection. Additionally, stress, alcohol, smoking and obesity have all been associated with psoriasis.
Impact of Psoriasis
The impact of psoriasis on quality of life is significant given how chronic and prevalent it is. Itching, scaliness and inflammation are the signs and symptoms of most concern to patients.
In recent patient surveys, reduced quality of life and the feeling that treatments often don‘t provide lasting results are current challenges. The goal is to find comprehensive, safe and effective long-term treatments that include modifying diet and lifestyle factors that can contribute to the disease.
There is currently extensive research taking place for new therapies for psoriasis. The most promising of these are the biological therapies. We also know that psoriasis can be associated with other conditions like heart disease, elevated cholesterol and Type 2 diabetes. Accurate diagnosis and a comprehensive approach to care are essential.