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, palms, and feet.

Like other autoinflammatory diseases, psoriasis occurs when your immune system — which normally attacks infectious germs — begins to attack healthy cells instead.

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.

• Discolored patches — classically, they’re red with silver scale on fairer skin tones and purple with gray scale on darker skin tones — or raised plaques of skin that are covered with scales
• Cyclic rashes that flare up for several weeks or months and then subside
• Dry or cracked skin that bleeds
• Burning, itching, or soreness near the affected areas
• Pitted or thickened fingernails or toenails

Psoriasis is largely genetic and is passed down through families. It affects about 2 percent of people in the United States.

“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, a dermatologist in Maywood, Illinois, who specializes in psoriasis.

• Being overweight or obese
• Having celiac disease
• Smoking
• Alcohol use or abuse

A psoriasis outbreak may be provoked by factors including:

Stress

“Psoriasis is very stress-dependent. It flares very easily when patients are under stress, and it tends to improve when they’re relaxed,” says Vesna Petronic-Rosic, MD, a visiting professor at the University of Illinois Chicago and the director of dermatopathology at John H. Stroger, Jr. Hospital of Cook County in Chicago. Stress management techniques, such as exercise, yoga, and meditation, may help manage psoriasis symptoms.

Cold Weather 

Dry Skin 

Anything that injures the skin, including excessively dry skin, can cause a psoriasis flare.

The solution: Keep your skin moisturized. If you’re allergic to the fragrances in moisturizers, use a product that’s fragrance-free to avoid a rash.

Vaccinations 

Beta-Blockers and Lithium 

If you’re taking beta-blockers or lithium, be sure to mention this to your dermatologist when discussing your psoriasis treatment plan.

Upper Respiratory Infections 

Smoking 

Diet 

Alcohol 

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. 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. Lesions 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.

Nail Psoriasis

People with nail psoriasis may experience symptoms like pitting, abnormal nail growth, and discoloration in their nails and toenails. It could cause onycholysis, which is when nails separate from the nail bed, causing more of the nail to look white than usual. People with severe nail psoriasis may experience crumbling of the nails.

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.

Psoriasis is considered a chronic, lifelong condition. There currently isn’t a cure, but there are treatments that can keep your skin clear or nearly clear.

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

• 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, but the FDA recently approved two nonsteroidal creams for psoriasis: roflumilast (Zoryve) and tapinarof (Vtama).

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• Biologics Biologic drugs are a type of systemic medication that impacts the entire body and alters the immune system. They are usually given as an injection, but some are available as a tablet. Biologics include etanercept (Enbrel), infliximab (Remicade), adalimumab (Humira), ustekinumab (Stelara), secukinumab (Cosentyx), ixekizumab (Taltz), brodalumab (Siliq), tildrakizumab (Ilumya), risankizumab (Skyrizi), guselkumab (Tremfya), deucravactinib (Sotyktu), and bimekizumab (Bimzelx).
• Apremilast (Otezla) 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.
• Methotrexate (Rheumatrex) This drug helps control inflammation.
• Cyclosporine (Gengraf or Neoral) This systemic treatment suppresses the immune system but can be taken for only short periods of time.

Light Therapy

• Take daily baths
• Keep skin moisturized
• Avoid triggers if you can
• Try not to scratch
• Get a small amount of sunlight each day, with guidance from your healthcare provider on how much sun exposure is safe for you
• Eat a nutritious diet
• Exercise regularly
• Maintain a healthy weight
• Limit or avoid alcohol

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

“Over the past 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 the Tulane University School of Medicine in New Orleans.

• Certain types of eczema, such as atopic dermatitis or seborrheic dermatitis
• Dandruff
• Ringworm
• Pityriasis rosea (a rash that usually starts as an oval spot on the chest, abdomen, back, or face)

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

The appearance of psoriasis can differ depending on race and ethnicity. 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 it can be deep brown and hard to see on people with very dark skin.

• Psoriasis is an autoimmune disease that causes itchy, dry, and sometimes sore patches of discolored skin.
• There are various types of psoriasis, and it’s caused by a combination of genetic and environmental factors — such as an inflammatory diet, stress, infections, cold weather, and certain medications.
• Psoriasis is linked to an increased risk of developing other health conditions, such as metabolic syndrome, diabetes, cardiovascular disease, and hypertension.
• Diet and lifestyle changes may reduce flare-ups, although you may require additional support from your dermatologist or primary care doctor. This may include topical creams, biologics, or pharmaceutical medications.