Psoriasis is a common chronic inflammatory disease of the immune system that speeds up the life cycle of skin cells. It typically involves the scalp, elbows, knees, hands, and feet, but can affect any part of the body such as the nails, mouth, and joints. As for its appearance, psoriasis appears as raised red patches and itchy white scales on the skin’s surface, which can either form on small sections of the body or cover the entire surface area of the skin. Psoriasis affects men and women equally, and is seen in people of all ages and races. Symptoms vary depending on the type, the most common of which is plaque psoriasis, and can negatively impact one’s psychological health, emotional well-being, and overall quality of life.
Scientifically speaking, psoriasis results from chronic changes in the epidermis, due to overstimulation of immune cells and excessive proliferation of keratinocytes that don’t mature correctly. Moreover, it is both a systemic and multifactorial disease. Systemic refers to the fact that psoriasis affects the entire body, not just the skin, and multifactorial means that it involves multiple factors, in this case environmental and genetic. Environmental factors which may trigger a psoriasis onset or flare-up include stress, cold and dry weather, HIV infections, trauma, withdrawal of corticosteroids, and certain drugs such as antimalarials, beta blockers, and lithium. In terms of genetic factors, these are still being researched, but scientists do know that psoriasis tends to run in families.
The most common symptoms of psoriasis include red rashes and inflamed skin that are covered with loose white scales, as well as itchy and painful skin that may crack or bleed, discoloration or pitting of the fingernails and toenails, and scaly plaques on the scalp. In addition to these, psoriasis is also associated with some serious health conditions such as type 2 diabetes, cancer, hypertension, heart disease, obesity, and inflammatory bowel disease. Furthermore, psoriasis is linked to autoimmune deficiencies like psoriatic arthritis, a condition of the joints that causes pain, swelling, and stiffness. In fact, 10 to 30 percent of people with psoriasis will also develop psoriatic arthritis.
Doctors diagnose psoriasis either visually or with a tissue biopsy, both of which are relatively straightforward processes. According to recent studies, at least 100 million individuals are affected by psoriasis worldwide, which is nearly 3 percent of the total population. In the United States alone, more than 8 million Americans have psoriasis and there are approximately 150,000 new cases each year. Nearly 60 percent of people with psoriasis report that the disease greatly impacts their everyday life, especially women and children. While the age of onset is usually between 15 and 35, psoriasis can develop in both younger and older individuals.
In terms of treatment, the three main types are topical, light therapy, and systemic medications. Topical treatments range from vitamin D analogues and Anthralin, to Calcineurin inhibitors and salicylic acid, to coal tar and moisturizers. Light therapy, or phototherapy, involves the use of natural or artificial ultraviolet light, either alone or in combination with medications. These include sunlight, UVB phototherapy, Goeckerman therapy, and excimer laser. Systemic medications, or oral and injected medications, are typically used as a last resort due to their severe side effects. Alternative treatments include lifestyle interventions and psychodermatology, the latter of which addresses the relationship between emotions and physical changes in the skin, using a combination of psychological and psychiatric techniques.