What Is Psoriasis? Symptoms, Causes, Diagnosis, Treatment, and Prevention

Psoriasis is an autoimmune disease that causes plaques, which are itchy or sore patches of thick, dry, discolored skin.

While any part of your body can be affected, psoriasis plaques most often develop on the elbows, knees, scalp, back, face, palms, and feet.

Psoriasis plaques can range from a few spots of dandruff-like scaling to major eruptions that cover large areas. The disease’s symptoms and appearance vary according to the type and severity of psoriasis.

Some common signs and symptoms include:

• Discolored patches or raised plaques of skin that are covered with scales
• Dry or cracked skin that bleeds
• Burning, itching, or soreness near the affected areas
• Pitted or thickened fingernails or toenails
• Swollen joints (1)

Learn More About Psoriasis Symptoms

Psoriasis, in general, is a genetic condition passed down through families. "It's likely that multiple genes need to be affected to allow psoriasis to occur and that it's frequently triggered by an external event, such as an infection," says James W. Swan, MD, professor of dermatology at the Loyola University Stritch School of Medicine in Maywood, Illinois.

There are five types of psoriasis, yet people most often have only one type of psoriasis at a time. Each type has its own set of symptoms.

Plaque Psoriasis

Also called psoriasis vulgaris, plaque psoriasis is the most common form of the skin disease. It appears as raised, discolored plaques covered with a scaly buildup of dead skin cells, or scales. The itchy, sometimes painful plaques can crack and bleed, and commonly affect the scalp, knees, elbows, back, hands, and feet.

Guttate Psoriasis

Often beginning in childhood or young adulthood, guttate psoriasis is the second most common type of psoriasis. Nearly 10 percent of people who get psoriasis develop guttate psoriasis, according to the NPF. Guttate psoriasis is the type of psoriasis most closely linked to a recent strep infection. If you develop guttate psoriasis, you will also likely be tested for strep bacteria.

Inverse Psoriasis

Also known as intertriginous psoriasis, inverse psoriasis causes red or otherwise discolored lesions in skin folds of the body that may look smooth and shiny. Each lesion can occur on the genitals or in areas near the genitals, like the upper thighs and groin. It's common for people with inverse psoriasis to have another type of psoriasis somewhere else on their body at the same time.

Pustular Psoriasis

This causes white blisters of pus that surround red or otherwise discolored skin, often on the hands or feet. The pus consists of white blood cells. When pus-filled bumps cover the body, you may have bright-red skin and feel ill or exhausted, and have a fever, chills, severe itching, rapid pulse, loss of appetite, or muscle weakness.

Erythrodermic Psoriasis

This is a dangerous and rare form of the skin disease characterized by a widespread, fiery redness or other discoloration and exfoliation of the skin that causes severe itching and pain. Erythrodermic psoriasis occurs once or more in 3 percent of people with psoriasis, according to the NPF.

Learn More About the Types of Psoriasis

There aren’t any special tests to help doctors diagnose psoriasis. Typically, a dermatologist will examine your skin and ask about your family history.

You’ll likely be given a diagnosis based on this physical exam.

In some situations, doctors will remove a small sample of the skin and examine it under a microscope. This might allow them to get a better look at the affected area and make a more accurate diagnosis. (11)

While psoriasis cannot be cured, there are effective options for treating it. Talk to your doctor about the benefits, risks, and side effects of any therapies you use.

Medication

Some medication to treat psoriasis includes:

• Topicals Prescription treatments, such as topical steroids, and over-the-counter (OTC) treatments that are applied directly to the skin can minimize symptoms of psoriasis. Each topical medication contains different active ingredients, such as salicylic acid, and can come as a lotion, cream, shampoo, gel, spray, or ointment. Topical corticosteroids are often prescribed for mild psoriasis or moderate psoriasis, according to the Mayo Clinic.
• Biologics Biologic drugs are a type of systemic medication, which impact the entire body and alter the immune system. They are usually given as an injection. They include Enbrel (etanercept), Remicade (infliximab), Humira (adalimumab), Stelara (ustekinumab), Simponi (golimumab), Cosentyx (secukinumab), Taltz (ixekizumab), brodalumab, tildrakizumab, and Skyrizi (risankizumab).
• Otezla (apremilast) This medicine comes as a pill and works by suppressing an enzyme that’s involved in inflammation.
• Oral Retinoids This type of systemic therapy is usually given if you have severe psoriasis that doesn’t respond to other treatments.
• Rheumatrex (methotrexate) This drug helps control inflammation.
• Cyclosporine (Gengraf, Neoral) This systemic treatment suppresses the immune system but can be taken for only short periods of time. (1)

Light Therapy

Light therapy, such as UVB phototherapy, involves exposing your skin to controlled amounts of natural or artificial ultraviolet light to help reduce symptoms of psoriasis. You may receive this treatment alone or along with other medication. (1)

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Having psoriasis can increase your risk for developing a number of health conditions, including:

• High blood pressure
• Obesity
• High cholesterol
• Diabetes
• Cardiovascular disease
• Osteoporosis
• Liver disease
• Kidney disease
• Cancer
• Uveitis (an eye disease)
• Crohn’s disease
• Depression (14)

"Over the last few years, we've seen that maybe psoriasis plays a more integral part in metabolic syndrome, a collection of symptoms that can lead to diabetes and heart disease," says Erin Boh, MD, chairman and a professor of dermatology at Tulane University in New Orleans and a member of the National Psoriasis Foundation board.

It is estimated that up to 30 percent of people with psoriasis will also develop psoriatic arthritis, an autoimmune disease that affects the joints. According to the National Psoriasis Foundation, psoriasis occurs before joint disease in 85 percent of psoriatic arthritis patients. (15)

The risks for psoriasis-related complications are greater the younger a patient is when diagnosed and the more severe the psoriasis. (16) Anyone with psoriasis should be aware that they are at risk for comorbid conditions and should monitor their overall health accordingly.

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According to the National Psoriasis Foundation, about 7.5 million people in the United States have psoriasis. Most are white, but the skin disease also affects Black, Latino, and Asian Americans as well as Native Americans and Pacific Islanders. (17)

The disease occurs about equally among men and women. According to the National Institutes of Health (NIH), it is more common in adults, and you are at a greater risk if someone in your family has it. (18) A study published in September 2016 in the journal PLoS One concluded that “interactions between particular genes as well as genetic and environmental factors play an important role” in the disease’s development. (19)

People with psoriasis generally see their first symptoms between ages 15 and 30, although developing the disease between 50 and 60 years of age is also common. (20)

“The biggest factor for determining prognosis is the amount of disease someone has,” says Michael P. Heffernan, MD, a dermatologist at the San Luis Dermatology and Laser Clinic in San Luis Obispo, California.

Psoriasis is less common in BIPOC (Black, Indigenous, and People of Color) populations compared with white ones, but it may be more severe and more challenging to diagnose.

According to research published in March 2014 in the Journal of the American Academy of Dermatology, psoriasis affects about 3.6 percent of Caucasians, as well 1.9 percent of African Americans and 1.6 percent of Hispanic Americans.

The appearance of psoriasis can differ depending on race and ethnicity. According to the American Academy of Dermatology (AAD), psoriasis tends to be red or pink with silvery-white scale in white patients, while a Hispanic person is more likely to have salmon-colored psoriasis and silvery-white scale. In Black Americans, psoriasis often looks violet and the scale gray, or can be a deep brown and hard to see on people with very dark skin.

Psoriasis can be more severe for people of color than white people, reports the National Psoriasis Foundation (NPF). A study published in the Journal of Drugs in Dermatology found that Asians with psoriasis had the highest percentage of body surface area affected (41 percent), while Caucasians had the lowest (28 percent).

The NPF notes that people of color who have psoriasis are less likely to get appropriate and timely treatment than their white counterparts. A study published in the January 2018 issue of the Journal of the American Academy of Dermatology found that Black, Asian, and Native Americans are 40 percent less likely to see a dermatologist for their psoriasis than non-Hispanic white Americans, regardless of their health insurance or socioeconomic status.

One reason more people of color with psoriasis are not receiving high-quality treatment may be systemic racism in the medical field and the health disparities it causes. An analysis of dermatology textbooks, published in June 2019 in the British Journal of Dermatology, showed that the number of images of skin of color ranged from 4 to 18 percent, with many textbooks showing zero images of skin of color with psoriasis.

Favorite Organizations for Essential Psoriasis Information

American Academy of Dermatology (AAD)

The AAD represents the vast majority of practicing dermatologists in the United States. Its website includes a tool that allows you to search its database to find dermatologists in your area.

American College of Rheumatology (ACR)

This global organization of physicians, health professionals, and scientists has provided a comprehensive website that offers a wealth of patient and caregiver resources, including educational videos, information on available medication and therapies, and a search tool to find a local rheumatologist.

National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)

Dedicated to supporting research to treat diseases affecting muscles, bones, joints, and skin, NIAMS offers a website that provides an exhaustive guide to skin conditions and related topics, as well as news on the most recent clinical trials.

National Psoriasis Foundation (NPF)

As the leading patient advocacy group for people living with psoriatic disease, the NPF provides an enormous online support community for people dealing with psoriasis. It provides a wealth of patient resources, including personalized guidance on how to deal with the disease.

Psoriasis and Psoriatic Arthritis Alliance (PAPAA)

Founded in 2007, this alliance of two former psoriasis-based foundations operates a website offering information, advice, and support for those living with psoriasis, including a special section for children coping with the disease.

Psoriasis Cure Now

This patient advocacy group specializes in raising awareness about the seriousness of psoriasis and the need for additional medical research. It also provides resources and information to encourage patients to advocate for themselves when seeking medical care.

The Skin of Color Society

This nonprofit works to increase awareness of dermatological issues as they impact the BIPOC community, working to educate physicians and the general public. A “Find a Doctor” database helps people with skin of color — including Black Americans, Asians, Hispanics or Latinos, Native Americans, and Pacific Islanders — connect with a clinician who is right for them.

Favorite Sites for Financial Assistance and Advocacy

National Psoriasis Foundation — Advocacy

NPF Advocacy helps organize volunteers to share information and advocate with legislators for change in public policy regarding psoriasis.

NeedyMeds

This online nonprofit information resource helps users to find programs that help patients who can’t afford medication and healthcare costs.

Partnership for Prescription Assistance (PPA)

The free PPA website helps users locate public and private assistance programs that can help cover expensive prescription medication costs.

Favorite Blogs

The Itch to Beat Psoriasis

Everyday Health contributor Howard Chang provides a firsthand perspective on psoriasis with an extra dose of encouragement, education, and empathy. Chang’s posts deal with the everyday details of living with psoriasis, including topics such as navigating the condition as a parent and how best to use the frequent time you spend in doctors’ waiting rooms.

Just a Girl With Spots

Having been diagnosed with psoriasis at 15, blogger Joni Kazantzis writes about not only her personal battles with the condition but also the mental and physical challenges that each person with psoriasis must battle daily.

Overcoming Psoriasis

Todd Bello was diagnosed with psoriasis at age 28. Through his blog, Bello shares regular posts about living with psoriasis as well as his patient advocacy efforts as a very active volunteer for the NPF. His passionate efforts on behalf of others with psoriasis have helped build a community of support for those dealing with the condition.

The National Psoriasis Foundation Blog

With the motto “The P is silent but we are not!” this blog is a frequently updated resource that covers a wide spectrum of psoriasis-related topics, including health, advocacy, and inspirational personal stories.

Favorite Retreats

Soap Lake Natural Resort and Spa

Soap Lake in Washington state has long been a popular destination for those dealing with skin conditions, thanks to the lake’s high natural mineral count and alkaline levels. In addition to specialized treatments, the Soap Lake Natural Resort and Spa also provides healthy dining options and a number of outdoor activities. Its accommodations also include in-room Jacuzzis that use water pumped from the lake, allowing you to experience the lake’s waters from the privacy of your room at any time during the year.

Blue Lagoon

Set in a volcanic Icelandic landscape, the Blue Lagoon resort provides luxury accommodations and fine dining, complete with a private lagoon at the Silica Hotel. Its best feature, however, may be the clinic, which is widely popular in treating psoriasis. Guests can bathe in the mineral-rich seawater of the lagoon, while other treatments include UV light therapy and a host of internally developed skin-care products.

Favorite Apps

Flaym

Created by the LEO Innovation Lab, this user-friendly app is a social media platform for people living with psoriasis. In addition to providing an easier way to connect with others dealing with the condition, it provides groups based on topic (parenting, diet, exercise, travel) and offers tools to help host meetups.

Imagine

This app allows you to document and track how your psoriasis develops over time by using your phone’s camera. The split-screen feature enables you to compare your condition over time and relate it to the effectiveness of your treatment with your dermatologist.