What Is Psoriasis?

Everything you need to know about this chronic autoimmune disorder

Psoriasis is an autoimmune skin disease. It occurs when the immune system malfunctions and attacks healthy tissues. These attacks produce inflammation that causes skin cells to produce too quickly, so they pile up as patches of skin, called plaques

There are different types of psoriasis, but the most common is plaque psoriasis, affecting 80% to 90% of the people with the condition.  Psoriasis plaques can appear anywhere on the body, but they most commonly appear on the knees, elbows, scalp, and trunk.

Psoriasis sometimes occurs with another autoimmune disease called psoriatic arthritis (PsA), which mainly affects the joints and the areas where ligaments and tendons meet bone.

This article covers the causes of psoriasis, its symptoms, diagnosis, treatment, and more. 

Close-up of psoriasis on an elbow


What Causes Psoriasis?

Psoriasis occurs when the immune system turns on the body's tissues. White blood cells, called T-cells, mistakenly attack skin cells, which causes skin cell production to increase. The new skin cells are pushed to the skin’s surface, where they pile up.

Many people inherit genes that make it more likely for them to develop psoriasis. If you have a family member with the condition, you are at a higher risk for psoriasis.

The symptoms of psoriasis can develop because of specific disease triggers. These, in combination with genetic predisposition, increase your risk for psoriasis.

Disease triggers that might lead to the development of psoriasis include:

Psoriasis Flare Triggers

Psoriasis is known for causing periods of flare-ups (also called outbreaks) when symptoms of the condition worsen. Triggers like stress, diet, smoking, alcohol consumption, skin trauma, illness, medications, and weather changes often cause flare-ups. 

  • Stress: Your immune system creates an inflammatory response to stress, which can lead to psoriasis symptoms. Try to reduce stressors through regular stress management activities. 
  • Diet: Research shows diet may play a part in the severity of psoriasis and the number of flares a person experiences. Eating a healthy diet with plenty of anti-inflammatory foods might help keep psoriasis symptoms at bay.
  • Smoking: Smoking, including secondhand smoke, is a known trigger for psoriasis. Aim to quit smoking and avoid secondhand smoke.
  • Alcohol consumption: Alcohol can trigger inflammation and worsening symptoms for some people with psoriasis. Alcohol might also reduce the effectiveness of medications and even lead to more severe drug side effects.
  • Skin trauma: An injury to the skin, such as a bug bite, scrape, bruise, or sunburn, can cause your psoriasis to flare up, especially in the skin trauma area. To reduce your risk of an outbreak, attend to skin injuries quickly by treating them, managing itching, and avoiding scratching. 
  • An illness: A psoriasis flare can occur from two to six weeks after an infection, such as strep throat or an earache. Reduce your risk of a flare by treating the infection quickly and taking time to rest and get better.
  • Medication: Some medications can trigger a psoriasis flare. You may have a flare two to three weeks later after starting a new medicine if it's a trigger.
  • Weather changes: Cold, dry weather can trigger a psoriasis flare. One study reported in 2015 found that people with psoriasis reported clearer skin in the summer months and more severe symptoms in the winter months.
  • Obesity: Fat tissue releases inflammatory proteins called adipokines, and research shows that weight loss can improve psoriasis symptoms. Weight loss might also improve response to psoriasis treatments. 

Psoriasis Symptoms 

Plaque psoriasis appears as plaques (thick skin areas) on different body areas. The plaques are sometimes covered with scales, a thick white coating of dead skin cells. On lighter skin tones, plaques appear red and are covered in silvery scales.

On darker skin, they may appear salmon-colored, dark brown, purple, or violet with grayish scales. People with darker skin might also have more scaling, more affected skin areas, and skin lesions misdiagnosed as hyperpigmentation because they appear as dark skin patches.

Psoriasis plaques can cover small body areas and large areas. Psoriatic lesions sometimes appear as small plaques that join to form large patches. Plaques will typically appear in the same areas on both sides of the body. For example, if one knee or elbow is covered, the other is also affected. 

Plaques will be itchy, painful, and tender. Scratching them can add to more of them, intensifying symptoms, and leading to broken, cracked, and infected skin.

Additional symptoms of psoriasis include:

  • Small, scaly, teardrop-shaped spots, which are more common in children
  • Dry, cracked skin that may also bleed
  • Itching or burning 
  • Sore, painful skin around patches 
  • Thick, pitted nails
  • Swollen, painful joints 

Psoriasis Severity

Psoriasis severity varies from person to person. The condition is measured on a scale from mild to severe. According to the National Psoriasis Foundation:

  • Mild: Psoriasis covers up to 3% of the body
  • Moderate: Psoriasis covers 3–10% of the body.
  • Severe: Psoriasis covers more than 10% of the body. It typically appears in many body areas, requires systemic (whole-body) treatment, and significantly affects a person’s quality of life.

When to See a Healthcare Provider

If you have skin irritation, a rash, or flaky, dry skin that lasts longer than a few weeks, you will want to see a healthcare provider who can examine your skin and determine the cause of skin lesions. For a correct diagnosis, you will want to see a dermatologist—a specialist in diagnosing and treating nail, skin, and hair conditions. 

If you have received a diagnosis of psoriasis and are experiencing new or worsening symptoms, you will want to reach out to your healthcare provider. You should also inform them if treatments don’t appear to be helping or if side effects affect your quality of life. 

Psoriasis vs. Eczema

Psoriasis and eczema can appear similar. Both cause discolored skin, rash, itching, and burning. These two conditions are often mistaken for each other, but a healthcare provider can tell them apart.

Psoriasis presents as thick, raised patches of skin, while eczema causes the skin to be red and inflamed. Eczema appears in body areas that bend, such as behind your knees and inside the elbow, but it can also appear on the face, neck, and wrists. In babies, eczema appears on the chin, cheeks, or scalp. Psoriasis appears on the fronts of elbows and knees, the trunk, hands, feet, nails, scalp, ears, and skin folds.

Eczema is triggered by irritants (i.e., soaps and detergents) and allergens (i.e., dust and pet dander). Conversely, psoriasis is triggered by stress, infection, and skin injuries. 

Diagnosis of Psoriasis

To diagnose psoriasis, your healthcare provider will ask questions about your health and examine your skin, nails, and scalp. They might also take a small sample of the affected skin (biopsy) to examine under a microscope. A skin biopsy can distinguish psoriasis from other skin diseases. 

Some questions your healthcare provider will ask to help diagnose psoriasis include:

  • Are you currently experiencing skin pain, itching, or swelling?
  • Has your skin been thick and scaly?
  • When did skin symptoms start?
  • Have you had joint pain, especially in the morning or after sitting for long periods?
  • When did joint symptoms start?
  • Do any family members have psoriasis or psoriatic arthritis? 
  • Have you had any recent significant stressors, such as a divorce, the death of a loved one, or a job loss?
  • Have you recently had a significant illness, such as an infection like strep or staph?
  • Have any over-the-counter (OTC) treatments helped with skin symptoms?

Types of Psoriasis 

There are different types of psoriasis, and when making a diagnosis, your doctor will want to determine which of these is causing your symptoms. It is possible to have more than one type, and some types often exist together.

Psoriasis types include:

  • Plaque psoriasis: The most common type of psoriasis, this causes thick, red lesions with silvery scales that pile upon the skin.
  • Guttate psoriasis: This type causes small, red scaly spots on the arms, legs, and torso. It typically starts after a bacterial infection.
  • Inverse psoriasis: This psoriasis type causes red, inflamed skin areas in body fold areas—the underarms, under the breasts, and around the genitals.
  • Pustular psoriasis: This is a rare kind of psoriasis that causes pus-filled bumps on the skin. Bumps often appear on the hands and feet. 
  • Erythrodermic psoriasis: This rare type causes a red rash resembling a burn over most of the body. It might also cause fever, chills, and dehydration. Erythrodermic psoriasis is a medical emergency and should be treated in a hospital.
  • Nail psoriasis: This type causes nails to become damaged, pitted, split, and lifted. It often occurs with plaque psoriasis and PsA.
  • Psoriatic arthritis: PsA affects some people with psoriasis. Symptoms include joint pain, severe swelling of the fingers and toes, inflammation in the areas where ligaments and tendons meet bone, and eye inflammation. 

Psoriatic Arthritis vs. Psoriasis

Psoriasis is a type of psoriatic disease. The second type is psoriatic arthritis, an autoimmune disease that affects 30% of people with psoriasis. It affects the joints and the entheses—the areas where ligaments and tendons meet bone. 

PsA typically occurs about 10 years after a psoriasis diagnosis. It is possible to have PsA first or have PsA and never develop psoriatic skin symptoms. 

Psoriasis Treatment 

The goal of psoriasis treatment is to stop skin cells from growing and remove scales. Your options for treating psoriasis are topical medicines (creams, ointments, etc.), oral and injected medicines, and phototherapy (light therapy).

The treatment your healthcare provider recommends will depend on the severity of your psoriasis symptoms and how responsive you have been to previous treatments. You might need to try different medicines or a combination of treatments before you find something that best works for you. 

Topical medicines: Topical medicines for psoriasis include calcineurin inhibitors, corticosteroids, coal tar, retinoids, salicylic acid, vitamin D creams, and anthralin (a tar cream). Many of these are prescribed alone or in combination with oral or injected medicines. Topical medicines are available over the counter (OTC) or by prescription.

Oral/injected medicines: If you have moderate to severe psoriasis or topical treatments have not helped you, your healthcare provider might prescribe systemic oral and injected medicines. These medicines are systemic because they affect the entire body and work to calm down your overactive immune system.

These include retinoids (to reduce skin cell production), biologics (to disrupt the disease’s processes and improve symptoms), and disease-modifying anti-rheumatic drugs (DMARDs) like methotrexate and cyclosporine (to suppress the immune system and slow down skin cell growth).

A Word About DMARDs and Biologics

Systemic medicines must be taken cautiously because they suppress your immune system, making you more vulnerable to severe infections. If you get an infection while treated with a DMARD or biologic medicine, you should immediately let your healthcare provider know. They may want to pause your systemic therapy until you have finished treating the infection.

Phototherapy: Also called light therapy, phototherapy is prescribed to people with moderate to severe psoriasis alone or with other therapies. It involves exposing the skin to consistent and controlled amounts of light.

Your options for light therapy might include Goeckerman therapy (light therapy with coal tar treatment), UVB broadband, UVB narrowband, psoralen plus ultraviolet A (PUVA), and excimer laser.

Is Psoriasis Curable?

Psoriasis is a lifelong condition that never goes away. There is no cure for it, and you will need to manage the condition for the rest of your life.

It typically goes through periods of flare-ups and remission (improved symptoms). The average time for remission is one to 12 months, but some people experience remission for a year or longer.

Even with remission, the underlying disease process is always there, and symptoms can return at any time. That is why staying on top of your treatment plan is crucial. 

The goals of psoriasis treatment are to reduce disease severity and improve quality of life. Healthcare providers focus on the goals that matter to the person living with psoriasis.

Alternative Treatments if Standard Treatment Isn’t Working 

Some lifestyle habits might affect the way your treatments work. For example, smoking and drinking alcohol might reduce the effectiveness of some medicines. Changing your lifestyle may help you better manage your psoriasis. Your healthcare provider can help you to decide what alternative treatments might help you.

Complementary and integrative therapies recommended by the National Psoriasis Foundation include:

  • Diet and nutrition: A healthy diet might help you lose weight, improve symptoms and reduce inflammation effects on your body. 
  • Physical activity: Exercise can improve your overall health, help you lose weight, and lower your risk for conditions linked to psoriases, like heart disease and type 2 diabetes.
  • Mind-body therapies: Therapies like yoga, tai chi, and meditation can help reduce stress and help you to manage psoriasis with an open mind.

Let your healthcare provider know if you want to try alternative therapies like acupuncture, herbal therapies, and dietary supplements. They can help you decide which therapies might benefit you and your unique health situation. 

How Long Will Treatments Take to Work?

When you start a new treatment, results will not come quickly. The National Psoriasis Foundation recommends waiting at least three months before deciding whether a treatment works. The organization considers a 75% improvement or reduced skin involvement to 3% body areas an acceptable treatment response.

Psoriasis symptoms do not go away overnight, so patience is key. Don’t stop taking medicines or going to light therapy appointments because symptoms have improved. Psoriasis is a chronic condition, which means you should never stop or change treatments without first checking with your healthcare provider. 

Risks and Complications Associated With Psoriasis 

People living with psoriasis might develop comorbid conditions—diseases that are present simultaneously with psoriasis. 

Some conditions affect people with psoriasis more frequently than others in the general population. These include heart disease, stroke, diabetes, inflammatory bowel disease, and depression. This is because the same inflammatory processes present in psoriasis are also responsible for many of these other very serious conditions.

Having psoriasis also increases your risk for serious infections. Medications for treating the condition suppress it and make it more vulnerable to bacteria, viruses, and pathogens. 

You can reduce your risk for disease complications by following your treatment plan exactly as prescribed. If you get sick, you want to reach out to your healthcare provider, follow their advice, and allow time to rest and get better to keep illnesses from becoming severe.

If you notice new or worsening symptoms, contact your healthcare provider immediately. These could be signs of another condition, worsening psoriasis, or reduced treatment response. Addressing these issues quickly helps you avoid serious problems.

Living With Psoriasis

Living with psoriasis is difficult. You might experience skin pain that causes burning, stringing, cracking, bleeding, and itching. If you have PsA, you might also experience joint pain and swelling in your fingers or toes and in the entheses. There are ways to address these problems.

Managing Triggers

You can identify what causes your psoriasis outbreaks by tracking when you experience symptoms and what leads to those. Your healthcare provider can also evaluate your treatment plan to help you reduce triggers.

Make sure you follow your treatment plan according to your healthcare provider's instructions. Don’t make any changes without first checking with your healthcare provider.

Keeping Skin Moisturized

Using a moisturizing cream can help you avoid dry skin, itching, and swelling. It also helps to heal your skin.

Softening Scales

You can use products containing salicylic or glycolic acids to soften scales. These ingredients help break up dead skin cells that build up on plaques.

Using Capsaicin for Joint Pain

Capsaicin is a substance in chili peppers, and it can help relieve joint swelling. You should check with your healthcare provider to see if it is safe to use on psoriatic skin.

Treating Itch

Many OTC options are available to manage itch, including hydrocortisone and lotions containing menthol or pramoxine. Ask your healthcare provider what they recommend for itchy skin. 

Using Cold Packs

Cold can help to manage joint swelling and itching. For itching, cold confuses the brain because it cannot feel cold and itchy at the same time. For joint pain, cold can bring down swelling.

Washing the Scalp With Vinegar 

According to the National Psoriasis Foundation, apple cider vinegar can help to calm an itchy scalp. You will want to avoid using vinegar if there is bleeding or cracking.

Psoriasis Statistics and Stigma

Psoriasis affects around 7.5 million American adults, according to a study reported in 2021 by JAMA Dermatology.

Because it is a visible condition, many people with psoriasis have encountered others who have misconceptions about it. A worldwide survey found that 84% of those with psoriasis had experienced humiliation or negative social consequences due to their condition.

Some people believe psoriasis isn’t treatable or that clear skin is impossible. But there are plenty of effective treatments. You can experience clear or nearly clear skin by working with your healthcare provider and following your treatment plan.

If anyone tells you psoriasis is just a rash, tell them this is not true. For most people with psoriasis, the condition causes problems in their everyday lives and can increase their risk for serious health problems, including depression and anxiety. 

Some people believe that psoriasis results from bad hygiene. But hygiene habits, good or bad, are not the cause of psoriasis. It is an autoimmune disease likely triggered by chronic stress or infection along with specific gene mutations.

The best way to help others deal with misconceptions about psoriasis is to educate them. There will be people in your life who are willing to listen and support you. There will be those who don’t listen or believe you. All you can do is educate and move on. 

Psoriasis Isn’t Contagious

Psoriasis is not a contagious condition. It occurs because of a problem with the immune system and is linked to genetics and environmental risk factors. 

You cannot catch psoriasis from someone else. You cannot catch it by kissing, hugging, having sex, being near someone with psoriasis, touching skin lesions, or even sharing personal care items. 


Psoriasis occurs because the immune system malfunctions and causes skin cells to grow too quickly, so they pile up.

It is characterized by periods of flare-ups in which you might experience a psoriasis outbreak and remission when the skin is clear or nearly clear. Flare-ups are triggered by specific stressors, including mental stress, skin trauma, illness, and lifestyle habits (e.g., smoking, poor diet, and drinking too much alcohol).

There are different types of psoriasis, but plaque psoriasis is the most common. It causes thick, red lesions. The condition is diagnosed with a medical history, physical exam, and a biopsy. Treatment aims to stop skin cells from growing and remove scales. Your treatment options for psoriasis include topical therapies, oral and injected medicines, and light therapy. 

There is no cure for psoriasis, but treatment is aimed at remission or nearly clear skin. It takes time for this to happen, so it is vital to be consistent with your treatment plan. Treatment is key to avoiding disease complications like severe infections and co-morbid conditions.  

It is important to be mindful of the misconceptions sometimes associated with psoriasis, including the notion that the condition is contagious. Psoriasis is a problem with the immune system, which means it cannot be passed to someone else through touching or close contact.

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Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Lana Barhum
Lana Barhum has been a freelance medical writer since 2009. She shares advice on living well with chronic disease.