Psoriasis

Psoriasis is a skin disease that causes itchy or sore patches of thick, red skin with silvery scales. The patches usually appear on the elbows, knees, scalp, back, face, hands and feet, but they can show up on other parts of the body.

Overview

Psoriasis is a chronic, long-lasting disease in which the immune system becomes overactive, causing skin cells to multiply too quickly. Patches of skin become scaly and inflamed, most often on the scalp, elbows, or knees, but other parts of the body can be affected as well.

Anyone can develop psoriasis, but it is more common in adults than in children, and it affects men and women equally. Psoriasis in children generally mirrors adult disease but with important pediatric-specific considerations.

Symptoms can go through cycles, flaring for a few weeks or months, followed by periods when they subside or go into remission. There are many ways to treat psoriasis, and the treatment plan depends on the type and severity of the disease.

Having psoriasis also carries the risk of developing other serious conditions.

Signs and Symptoms

Symptoms of psoriasis vary from person to person. Common symptoms include:

  • Patches of thick, red skin with silvery-white scales that itch or burn, typically on the elbows, knees, scalp, trunk, palms, and soles of the feet
  • Dry, cracked skin that itches or bleeds
  • Thick, ridged, pitted nails
  • Poor sleep quality

Symptoms can come and go. There are times when symptoms get worse, called flares, followed by times when symptoms lessen or disappear.

There are several different types of psoriasis:

  • Plaque psoriasis: This is the most common kind. It appears as raised, red patches of skin covered by silvery-white scales. The patches usually develop in a symmetrical pattern and tend to appear on the scalp, trunk, and limbs, especially the elbows and knees.
  • Guttate psoriasis: This type usually appears in children or young adults and looks like small, red dots, typically on the torso or limbs. Outbreaks are often triggered by an upper respiratory infection, such as strep throat.
  • Pustular psoriasis: In this type, pus-filled bumps called pustules appear surrounded by red skin. It usually affects the hands and feet, but there is a form that covers most of the body. Symptoms can be triggered by medicines, infections, stress, or certain chemicals.
  • Inverse psoriasis: This form appears as smooth, red patches in folds of skin, such as under the breasts or in the groin or armpits. Rubbing and sweating can make it worse.
  • Erythrodermic psoriasis: This is a rare but severe form characterized by red, scaly skin over most of the body. It can be triggered by a bad sunburn or certain medicines, such as corticosteroids. It often develops in people who have another type of psoriasis that is not well controlled, and it can be very serious.

People with psoriasis face a higher risk of several other conditions:

  • Psoriatic arthritis, a chronic form of arthritis that causes painful, swollen, and stiff joints and the places where tendons and ligaments attach to bones
  • Cardiovascular events, such as heart attacks and strokes
  • Mental health problems, including low self-esteem, anxiety, and depression
  • Certain cancers
  • Crohn’s disease
  • Metabolic disorders and symptoms such as diabetes, metabolic syndrome, obesity
  • Osteoporosis
  • Uveitis (inflammation of the middle of the eye)
  • Liver disease
  • Kidney disease

Causes and Risk Factors

Psoriasis is an autoimmune disease. Immune cells become active and produce molecules that trigger the rapid production of skin cells. Scientists do not fully understand what triggers this faulty immune cell activation, but they know it involves a mix of family history and environmental factors.

Many people with psoriasis have a family history of the disease, and researchers have identified some of the genes that may contribute to its development, many of which play a role in immune system function.

External factors that may increase the chances of developing psoriasis include:

Diagnosis

To diagnose psoriasis, the doctor examines the skin, scalp, and nails for signs of the condition. The doctor may also ask questions about medical and family history, such as whether the person:

  • Experiences symptoms such as itchy or burning skin
  • Had a recent illness or experienced severe stress
  • Takes certain medicines
  • Has relatives with the disease
  • Experiences joint tenderness

To rule out other skin conditions that look like psoriasis, the doctor may take a small skin sample to examine under a microscope. Conditions that can mimic psoriasis include eczema, seborrheic dermatitis, contact dermatitis, pityriasis rosea, lichen planus, ringworm, tinea versicolor, rosacea, lupus, scabies, keratosis pilaris, hives, shingles, and certain types of skin cancer.

If psoriatic arthritis is suspected, the doctor may also:

Treatment and Management

There is currently no cure for psoriasis, but treatments can keep symptoms under control so that those affected can resume daily activities and sleep better. Managing known triggers can help keep symptoms under control. These include stress, skin injuries, certain medicines, and infections.

A healthcare provider can discuss which treatment is best, based on the type of psoriasis, where on the body and how severe it is, and the possible side effects of medicines. During pregnancy, managing psoriasis requires balancing symptom control with fetal safety.

Medicines

  • Topical therapies: Creams, ointments, lotions, foams, or solutions, especially those containing corticosteroids, are commonly used to treat mild to moderate psoriasis. Other topical therapies include vitamin D-based medicines, retinoids (related to vitamin A), anthralin, phosphodiesterase 4 (PDE4) inhibitors, and medicines activating the aryl hydrocarbon receptor (AhR).
  • Methotrexate: Available in oral or injected form, this medicine suppresses the immune system and slows down cell growth and division.
  • Oral retinoids: These compounds, related to vitamin A, may help some people with moderate to severe psoriasis and can be used in combination with phototherapy.
  • Biologic response modifiers: These injected medicines block specific immune molecules, helping to decrease or stop inflammation.
  • Immunosuppressants: Normally used for severe cases, these medicines work by suppressing the immune system.
  • Oral phosphodiesterase 4 (PDE4) inhibitors: These target enzymes inside immune cells and suppress the rapid turnover of skin cells and inflammation.
  • Oral tyrosine kinase 2 (TYK2) inhibitors: These medicines block the activation of certain immune cells.

Phototherapy

Phototherapy involves having a doctor shine ultraviolet light on the skin. Phototherapy is usually used when psoriasis affects large areas of the skin.

Note: Extra exposure to the sun’s ultraviolet rays may increase skin cancer risk.

Dead Sea Climatotherapy

A form of bathing therapy called Dead Sea climatotherapy (an artificial climatotherapy that mimics the mineral-rich waters of the Dead Sea environment and increased sun exposure) has been shown to be helpful for psoriasis.

Emerging Therapies

Emerging therapies for psoriasis are showing promising efficacy and safety. These include IL‑23 inhibitors like icotrokinra, oral TYK2 inhibitors, GLP‑1 receptor agonists, oral IL‑17 inhibitors, and nanobody‑based biologics.

Living With Psoriasis

Psoriasis can affect a person’s daily life, including work and sleep. Healthcare providers can work with patients to help reduce symptoms.

Other ways to help manage psoriasis symptoms include:

  • Keep skin well moisturized: Bathe in lukewarm water and use mild soap that has added oils. After bathing, apply heavy moisturizers while the skin is still damp.
  • Maintain a healthy weight: Obesity can worsen psoriasis symptoms.
  • Eat a healthy diet: The Mediterranean diet has been shown to be helpful in several psoriasis studies.
  • Exercise: For people with psoriatic arthritis, low-impact activities such as walking, cycling, swimming, yoga, or tai chi may be especially helpful. Talk with a doctor before starting any exercise program.
  • If you smoke, try to quit: Studies show the more a person smokes, the worse the symptoms.
  • Reduce alcohol consumption: Some studies suggest that excessive alcohol consumption aggravates symptoms.
  • Expose skin to small amounts of sunlight: Limited sunlight can alleviate symptoms, but too much can make them worse, so consult a doctor for advice.
  • Avoid known triggers: Try to identify what triggers psoriasis flares and work to avoid them. Some people have found that stress, cold weather, skin injuries, certain medicines, and infections spark flares.
  • Join a support group or visit a mental health provider: Psoriasis can affect a person’s mental health, increasing the risk of anxiety and depression. Seeking support can help patients living with the disease.

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on psoriasis.

Find Treatment

Psoriasis is treated by dermatologists, who specialize in conditions of the skin, hair, and nails.

Other healthcare providers who may be involved in the care plan include:

  • Rheumatologists, who specialize in conditions of the joints, muscles, and bones, and provide care to people with psoriatic arthritis
  • Primary healthcare providers, including family doctors, internists, pediatricians, or nurse practitioners
  • Mental health professionals, who provide counseling and treat mental health disorders such as depression and anxiety
  • Physiatrists (rehabilitation specialists), who supervise exercise programs
  • Occupational therapists, who teach ways to protect joints, lessen pain, perform daily activities, and conserve energy
  • Physical therapists, who help improve joint function
  • Dietitians, who teach about nutrition and maintaining a healthy weight

Community Support

The following organizations offer information and support for people with psoriasis:

Note: This resource list is for informational purposes only. It is not comprehensive, and an organization’s inclusion does not constitute an endorsement by NIH. 

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.

NIH supports research to understand what causes psoriasis, identify new treatments, and uncover other conditions associated with the disease. Examples of current research include:

  • Performing molecular and genetic analyses of people with the disease to better understand how psoriasis starts and help identify new treatment targets
  • Studying the makeup of the human microbiome in people with psoriasis and how it may affect psoriatic disease outcomes
  • Investigating whether there are shared genetic risk factors among psoriasis and related conditions such as diabetes, obesity, and liver disease
  • Focusing on patients’ satisfaction with psoriasis therapies to help inform shared decision-making between clinicians and patients, predict whether patients are following their treatment plan, and improve the likelihood of long-term treatment success

The NIH-supported Accelerating Medicines Partnership® Autoimmune and Immune-Mediated Diseases (AMP® AIM) Program aims to deepen understanding of the cellular and molecular interactions that lead to inflammation and autoimmune diseases, including psoriasis and psoriatic arthritis.

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies. 

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Psoriasis Explained