What is psoriasis? Psoriasis is an autoimmune disorder that mainly affects the skin: The body’s immune system triggers inflammation within the dermis, the thick layer of skin under the epidermis. This causes overproduction of skin cells. Instead of normal skin cell turnover taking weeks, new skin cells grow in days. Old skin cells do not slough off fast enough, so layers of skin cells form red, scaly patches. In its most common form, plaque psoriasis, skin lesions mainly form on the elbows, knees, scalp, low back and belly, the cleft between the buttocks and thigh, and the genitalia. Psoriasis can also affect the nails. Symptoms include peeling and flaking skin, itchy skin, rash, and skin pain, bleeding, and redness. Skin lesions are not due to infection, and psoriasis is not contagious. An autoimmune form of arthritis—psoriatic arthritis—develops in about 30% of psoriasis patients. What are the different types of psoriasis? Psoriasis is characterized by how it looks and its severity. The five types of psoriasis include: Plaque psoriasis, or psoriasis vulgaris appears as raised red patches with silver-white layers of dead skin cells on top. Guttate psoriasis, the second-most common type of psoriasis appears as small but raised, dot-like red lesions. Pustular psoriasis appears as blister-like lesions filled with white blood cells. The surrounding skin is red. Inverse psoriasis appears as large red areas in body folds including underarms, behind the knee, and groin. Typically, the lesions are not raised or scaly because the environment is moist and sweaty. It can occur with other types of psoriasis. Erythrodermic psoriasis appears as very inflamed red skin over most of the body. Approximately 3% of people with psoriasis develop an erythrodermic psoriasis flare-up one or more times. It is a dangerous condition that requires immediate medical supervision. Who gets psoriasis? In the United States, about seven million people (adults and children) have psoriasis, which is just over 2% of the population. Psoriasis is a multifactorial disease, meaning both genetic and environmental factors can contribute to its cause. This makes it difficult to know who will or won’t develop it. However, experts who study psoriasis report these facts: Individuals with an affected biological parent have a 10% chance of developing psoriasis. The risk jumps to 50% if both parents have the condition. Most people are between 15 to 35 years of age at the time of diagnosis. Another common age range for diagnosis is 50 to 60 years. About 10 to 15% of individuals, or 20,000, are younger than 10 years of age when diagnosed; psoriasis rarely affects infants. Psoriasis is more prevalent in non-Hispanic white Americans, as compared to other races and ethnic groups. What are some conditions related to psoriasis? Psoriasis is an inflammatory disease caused by an abnormal immune response. Other autoimmune or inflammatory conditions related to psoriasis include: Psoriatic arthritis—a type of inflammatory arthritis that develops in about 30% of psoriasis patients. It can also develop before skin symptoms appear. Scleroderma—an autoimmune disorder that causes inflammation in the skin and other connective tissues. Rheumatoid arthritis—an autoimmune disorder that causes painful joint inflammation. How does psoriasis affect quality of life? Lifelong diseases, especially those that are visible to others, can be overwhelming physically, emotionally and financially. In one large U.S. study, 38% of patients reported an impact on physical functioning. The physical burden of psoriasis itself is aggravated by these other serious conditions: Psoriatic arthritis—patients with both psoriasis and arthritis report a greater impact on quality of life than those with either condition alone. Another autoimmune disease—people who have psoriasis are nearly twice as likely as the general population to have another autoimmune disease, such as rheumatoid arthritis, lupus, Sjogren’s syndrome, celiac disease, or inflammatory bowel disease. Cardiovascular problems—the rate of heart attack in psoriasis patients may be up to twice that of the general population. Obesity—the rate of obesity is higher in people who have psoriasis and it is also a risk factor for psoriasis. Metabolic syndrome is also more common in people with psoriasis. Sleep disorder—more than 50% of psoriasis patients complain of sleep disturbances. In the same U.S. study, 98% of psoriasis patients reported an emotional impact, and 94%, an impact on relationships and activities. The social-emotional burdens of psoriasis include: Depression—this mood disorder is 1.5 times more prevalent in people with psoriasis, as compared to the general population. Suicidality is also a major concern. Anxiety and stress—not only do people with psoriasis have greater rates of anxiety and stress, but the physiological effect of these conditions can make psoriasis worse. Sexual difficulty—an effect on intimate relationships was reported by 17% of respondents in the study. As for the financial burden, a typical psoriasis patient pays approximately $2,528 in out-of-pocket medication costs annually. The cost of treatment and potential for side effects can also interfere with some psoriasis patients seeking medical care. Can you die from psoriasis? As the skin is supposed to act as a natural barrier and protectant, the compromising effects of psoriasis can be life threatening. In particular, complications of pustular and erythrodermic psoriasis, such as dehydration and infection, can be fatal. Larger research studies are necessary to determine the specific causes of death in psoriasis patients; however, mortality is linked to both disease severity and cardiovascular disease. Doctors recommend regular checkups for psoriasis patients, especially those with more severe cases, to screen for heart disease and other comorbid conditions. Experts also recommend leading a heart-healthy lifestyle to help reduce the risk of heart disease and improve life expectancy. What causes psoriasis? The underlying cause of psoriasis involves a complex interaction between a person’s genetic makeup and environmental factors. Scientists who study psoriasis know: Certain variations, or alleles, of immune system genes prime the abnormal immune reaction and skin cell overproduction seen in psoriasis patients. Research has identified at least 60 different genes involved in psoriasis. In some cases, these psoriasis susceptibility genes are inherited. In most other cases, the variations arise by chance. Scientists estimate 10% of the population is susceptible, but only 2 to 3% of the U.S. population develop the condition. A nongenetic factor, such as exposure to certain climates, medications, emotional stresses, skin stress or injury, or infections can help trigger the disease in people with genetic risk factors. Smoking, obesity, and metabolic syndrome are also strong risk factors for psoriasis. How are you diagnosed with psoriasis? In most cases, a dermatologist diagnoses psoriasis with a physical exam of the skin. However, a skin biopsy may be necessary to rule out or confirm other diagnoses. These include atopic dermatitis (eczema), skin reactions, and allergies. There is no blood test for psoriasis, but doctors may order a complete blood count prior to beginning treatment. The doctor will also look for signs of joint involvement. What are common treatments for psoriasis? Many treatments are available to quiet psoriasis symptoms and drive the disease into remission. There is no cure for psoriasis, but consistent and continuous psoriasis treatment calms the immune system, improves skin symptoms, and helps patients enjoy more normal lives. Categories of drugs for psoriasis include: Topical drugs, in mild cases—where the disease affects less than 5% of body surface area and does not involve the hands, feet or genitalia. Phototherapy including ultraviolet B (UVB) and UVA light treatments, in moderate to severe cases. Doctors may combine light therapy with topical and systemic drugs—those that work throughout the body. Disease-modifying antirheumatic drugs (DMARDs), such as methotrexate and cyclosporine. Biologic drugs, also known as biologic response modifiers or immunomodulators. These drugs target the abnormal immune response in psoriasis patients. They also work for other autoimmune conditions. Additional psoriasis facts The social stigma of psoriasis will likely improve with increased awareness, such as highlighting celebrities with psoriasis. But improving the lives of people with psoriasis is most important. In 2016, the National Psoriasis Foundation medical board established a goal of limiting plaque psoriasis lesions to 1% or less of body surface area within three months of starting treatment. Indeed, patients and doctors working together on a common “treat to target” goal will help improve quality of life for the millions of Americans with psoriasis. August is National Psoriasis Month. Learn more about psoriasis and related conditions at the National Psoriasis Foundation.