January 30, 20190806

What is Psoriasis?

Psoriasis is a common autoimmune disease. The World Health Organization (WHO) estimates that over 100 million people have psoriasis worldwide.1

Psoriasis occurs when your body produces too many T-cells, a type of white blood cell.5 The excess T-cells attack your healthy skin cells, instead of fighting infections.5 This attack causes your skin to develop thick, red patches and/or silvery scales that itch or hurt. This is often referred to as “plaque psoriasis.”1,5

Psoriasis sometimes causes joint pain, called psoriatic arthritis.2 If you have psoriasis, you may be at higher risk for other health conditions. These include diabetes, heart disease and depression.1,3

So far, researchers have been unable to tell what causes psoriasis. They do know, however, that you cannot get psoriasis by touching someone who already has it. It is not contagious.4

Researchers believe that you can, however, inherit psoriasis. It is estimated that 30 percent of people with psoriasis have a family history of the disease.4

Since scientists are unsure what causes psoriasis, they have not been able to develop a cure. However, there are many treatment options available that can help control your symptoms.


Symptoms of Psoriasis

The most common symptoms of psoriasis are1,4:

  • a localized or widespread red, swollen rash
  • scaly skin
  • flaky skin
  • itchy skin

Depending on the type of psoriasis, the rash can have a variety of shapes and appear on different parts of your body. Most commonly, psoriasis appears on your face, scalp, hands, legs, elbows, or knees.4

The symptoms of psoriasis can be mild or severe. If left untreated, the symptoms can worsen. Severe psoriasis can even progress to open wounds. These wounds hurt and may ooze or bleed.1


Psoriasis on the face and neck


A picture of psoriasis on the neck (iStockphoto/Srisakorn).


It is rare to have psoriasis just on your face. Most often, if you have facial psoriasis, you will also have psoriasis on your scalp or another part of your body.16

Facial psoriasis is often difficult to treat. This is because the skin on the face is thinner and more sensitive than other places on the body. Facial psoriasis may be treated using any of the treatment methods discussed below.16


Psoriasis on the scalp

A picture of psoriasis on the scalp (iStockphoto/Farina2000)

The scalp is a very common place for people to have plaque psoriasis. About 50 percent of people with psoriasis have it on their scalp.15

Scalp psoriasis can be harder to treat than other forms of psoriasis because it is under your hair. Scalp psoriasis is usually treated with a medicated shampoo. This allows the medicine to get around your hair to the skin that needs to be treated.15

Common drugs in shampoos for treating scalp psoriasis include coal tar and salicylic acid.15

Sometimes, scalp psoriasis can cause your hair to fall out. The hair usually grows back after the psoriasis flare-up is over.14


Psoriasis on other parts of the body


A picture of psoriasis on the fingers (iStockphoto/Photopips)


In addition to the face and scalp, psoriasis can occur basically anywhere else on the body. If you have psoriasis somewhere other than your face or scalp, it is most often on your joints—such as your elbows, knees, or knuckles.4


Types of Psoriasis

Plaque Psoriasis is the most common form of psoriasis. It occurs as swollen red patches with silvery scales (plaques). These scales are a build up of dead skin.

These scales can appear anywhere on the body, but most often occur on the elbows, knees, scalp and lower back. You can have patches of plaque psoriasis in just one place on your body, or in many places at once.

The plaques are often itchy. Scratching can cause the plaques to bleed, depending on how far into your skin the rash goes.1,4

Guttate Psoriasis is the second most common type of psoriasis. This type of psoriasis causes small pearl-shaped rashes that can occur anywhere on the body. They are most often found on the back, sides or stomach.

Guttate psoriasis occurs frequently in children after an infection like strep throat, an ear infection, or bronchitis.4

Inverse Psoriasis, also known as flexural psoriasis, presents as swollen red patches in the folds of your skin. This skin is vulnerable to psoriasis because it is often already irritated by sweat.1

Inverse psoriasis is found in folds of skin such as under the arm, behind the knee or the groin area.1

You are at greater risk for inverse psoriasis if you are obese.1

Pustular Psoriasis causes pus-filled blisters circled by red skin. This type of psoriasis can be localized to one area, or widespread. If it is localized, it usually affects your hands and/or feet.4

Erythrodermic Psoriasis is a life-threatening form of psoriasis. In this form of psoriasis, your rash becomes extremely widespread, with reddening and scaling appearing on large areas of your body.4

Erythrodermic psoriasis often develops from chronic, poorly-treated plaque psoriasis.4

Erythrodermic psoriasis can be very serious and requires immediate medical attention.4

Psoriatic Arthritis is a condition in which a person has joint pain similar to arthritis. In this condition, the same inflammation that causes red patches on the skin occurs in your joints, causing pain and swelling. Left untreated for as little as six months, psoriatic arthritis can cause permanent joint damage and deformities.18

About 30 percent of people with psoriasis develop psoriatic arthritis. There is little connection between the severity of your psoriasis and whether or not you will get psoriatic arthritis.18

Common symptoms of psoriatic arthritis include18:

  • Fatigue
  • Tenderness and swelling over tendons
  • Swollen fingers or toes
  • Reduced range of motion
  • Stiffness, especially in the morning, and
  • Red eyes


If you think you may have psoriatic arthritis, you should see a rheumatologist. She will be able to tell you if you have psoriatic arthritis, or a different joint disease.18 Once you have a proper diagnosis, she will also be able to provide you with the correct treatments to control your symptoms.


Treatment of Psoriasis

Psoriasis does not have any known cure, even though it has been around for a very long time.1 There are, however, many treatment options that can help control your symptoms.

Today, doctors treat psoriasis in two main ways. They are classified by how the treatment is given.

They two classes of treatments are2:

  • External Treatments
  • Systemic Treatments


External Treatment

External treatment of plaque psoriasis includes the use of creams or lotions on the rashes or exposing the rashes to sunlight (light therapy). External treatments can be effective for mild psoriasis. They are, however, usually ineffective for moderate or severe psoriasis.2

Topical Skin Creams and Lotions

Many different skin creams exist that can help treat the symptoms of psoriasis. These creams can contain steroids, vitamin D3, retinoids (vitamin A), coal tar or anthralin.1,6

Treatments with these skin creams are so common that the WHO has named steroid and coal tar creams to its list of essential medicines for the treatment of psoriasis.1

Some of the creams and lotions used to treat psoriasis can be purchased over-the-counter.1,6 These include coal tar, hydrocortisone, and salicylic acid (also used to treat acne).

Others you can only buy with a prescription from your doctor. These include anthralin, Dovonex, Tazorec and concentrated steroid creams.11,12

Many of these skin creams, both prescription and over-the-counter, have side effects. Depending on the drug in the cream, these may include10:

  • Dry skin
  • Reddening of the treated skin
  • Irritation in or around the treated area
  • Sensitivity to the sun in or around the treated are


Light Therapy

Over the years, doctors have developed better ways of providing light treatments than simply having you sit in the sun for hours. Today, doctors use a special lamp that only emits the kind of light waves that help improve the symptoms of psoriasis.9 Though this is much safer than being exposed to all the light waves made by the sun, excessive use of these lamps may still increase your risk of cancer.6 You should only use light therapy lamps under the supervision of your doctor to make sure that you do not put yourself at risk for cancer.

Today, external treatment of moderate cases of psoriasis almost always includes both light therapy and creams or lotions.6


Systemic Treatment

Systemic treatment consists of using drugs, either taken by mouth or by injection, to treat psoriasis internally. Systemic treatment is used for moderate to severe cases of psoriasis.6

If your doctor orders systemic treatment of your psoriasis, you may be given many different drugs. These may include retinoids, cyclosporine, methotrexate or biologic response modifiers.7


Retinoids are chemicals made from vitamin A.7 The most common retinoid that you take as a pill to treat psoriasis is called Acitretin.

Your doctor may prescribe Acitretin if you have a serious form of psoriasis. Examples of serious types of psoriasis include pustular psoriasis and erythrodermic psoriasis.7

Cyclosporine and methotrexate

These drugs work by suppressing your immune system. This slows down the production of T-cells, which are responsible for causing your psoriasis.2,6

You can take these drugs as a pill or an injection.2,6 They have proven to be effective treatments for severe cases of psoriasis, and are included on the WHO’s list of essential medicines.1

They are, however, not risk-free. Since they suppress your immune system, you are at higher risk for getting an infection while on these drugs.6

Biologic response modifiers

Like cyclosporine and methotrexate, this class of drugs also works by interfering with the production of your T-cells. Rather than being made by chemists in a lab, however, these drugs are made by living cells.8

Examples of biologic response modifiers include Enbrel (etanercept), Humira (adalimumab) and Stelara (ustekinumab).8

You take these drugs as an injection or an IV.8

Like cyclosporine and methotrexate, these drugs will make you susceptible to infections. Your doctor will monitor you closely if you are on this drug.8


Prevention of Psoriasis

For most diseases an ounce of prevention can be worth a pound of cure. Psoriasis is no different.

Doctors recommend that if you (or someone in your family) have a history of psoriasis, you should keep your immune system working optimally by3,13:

  • eating a healthy, balanced diet, rich in immune calming foods, such as fish and nuts


  • exercising regularly

You may be able to further prevent psoriasis by avoiding psoriasis triggers. Many different things can trigger psoriasis, including5:

  • Infections
  • Skin injuries, like cuts, scrapes, bug bites, or sunburn
  • Stress
  • Smoking
  • Heavy alcohol consumption
  • Low vitamin D levels
  • Certain prescription drugs, including drugs that treat high blood pressure


Scientists have also been able to show that certain foods may be able to trigger psoriasis by increasing the activity of your immune system. Those foods include13:

  • red meat
  • dairy products
  • processed foods
  • refined sugars
  • nightshade vegetables (tomatoes, peppers, and potatoes).


Avoiding these foods and other triggers may help keep you from developing psoriasis.

It is worth noting here that gluten, though suspected as a trigger for a while, is now believed to be safe for most people with psoriasis.  Extensive studies have found no evidence that a gluten-free diet can help prevent or treat psoriasis, unless you have celiac disease (an autoimmune disease caused by gluten).13

If you notice a rash that may be psoriasis, have it examined by your doctor. Early detection and treatment of psoriasis can help prevent it from getting worse.1


Psoriasis FAQ

Is psoriasis contagious?

No, psoriasis is not contagious. You cannot get it by touching a person who already has it. This is because psoriasis is not caused by a bacteria, fungus or virus. Rather, it is caused by the over-production of T-cells by your immune system. These T-cells attack your healthy skin cells, causing the rash.1

Can you die if you have psoriasis?

In nearly all cases, psoriasis is not life-threatening. There is one rare form, however, that can be fatal. This form is called erythrodermic psoriasis.19

Psoriasis can increase your risk for some diseases, such as diabetes and heart disease, though, which may be fatal.19

What causes psoriasis to spread?

Many things can cause your psoriasis symptoms to worsen. These include things like a poor diet, stress, smoking, drinking alcohol, and taking certain drugs. If you have a history of psoriasis, try as much as possible to live a healthy lifestyle. Your doctor may be able help you with this.5

How much do psoriasis drugs cost?

The cost of psoriasis drugs varies greatly. Common skin creams cost up to around $500 per year. New biologic drugs can cost up to $20,000 per year.20

This might not be how much you have to pay out of pocket, though. Many health insurance policies cover at least some of the cost of drugs that can be used to treat your psoriasis.20



  1. Global Report on Psoriasis. World Health Organization. 2016. Available at Accessed July 26, 2017.
  2. Psoriasis | American Academy of Dermatology. Aadorg. 2017. Available at: Accessed July 26, 2017.
  3. Gelfand JM. “Dermatologists urge psoriasis patients to be aware of potential link to other serious diseases.” Presentation to the American Academy of Dermatology. March 13, 2012. Available at: Accessed July 26, 2017.
  4. About Psoriasis | National Psoriasis Foundation. Psoriasisorg. 2017. Available at: Accessed July 26, 2017.
  5. Psoriasis – Symptoms and Causes | Mayo Clinic. Mayoclinicorg. 2017. Available at: Accessed July 26, 2017.
  6. Menter A, Korman NJ, Elmets CA, Feldman SR, Gelfand JM, Gordon KB et al. Guidelines of care for the management of psoriasis and psoriatic arthritis: section 4. Guidelines of care for the management and treatment of psoriasis with traditional systemic agents. J. Am. Acad. Dermatol. 2009;61:451-85.
  7. Retinoids and Psoriasis. Papaaorg. 2017. Available at: Accessed July 27, 2017.
  8. Moderate to severe psoriasis – biologic drugs | National Psoriasis Foundation. Psoriasisorg. 2017. Available at: Accessed July 26, 2017.
  9. Over-the-counter (OTC) Topicals | National Psoriasis Foundation. Psoriasisorg. 2017. Available at: Accessed July 26, 2017.
  10. Mild Psoriasis: Non-steroidal Prescription Topical Treatments | National Psoriasis Foundation. Psoriasisorg. 2017. Available at: Accessed July 26, 2017.
  11. Mild psoriasis: Topical Steroids | National Psoriasis Foundation. Psoriasisorg. 2017. Available at: Accessed July 26, 2017.
  12. Diet and psoriasis | National Psoriasis Foundation. Psoriasisorg. 2017. Available at: Accessed July 26, 2017.
  13. Scalp psoriasis | The Psoriasis and Psoriatic Arthritis Alliance. Papaaorg. 2017. Available at: Accessed July 26, 2017.
  14. Scalp psoriasis | National Psoriasis Foundation. Psoriasisorg. 2017. Available at: Accessed July 26, 2017.
  15. Facial psoriasis | DermNet New Zealand. Dermnetnzorg. 2012. Available at: Accessed July 26, 2017.
  16. Types of Psoriasis | Mayo Clinic. Mayoclinicorg. Last updated March 7, 2015. Available at: Accessed on July 26, 2017.
  17. About psoriatic arthritis | National Psoriasis Foundation. Psoriasisorg. 2017. Available at: Accessed on July 26, 2017.
  18. Can severe psoriasis be fatal? Psoriasisbustersca. 2016 Available at: Access on July 26, 2017.
  19. 5 Ways to Handle the Cost of Psoriasis Care. Everydayhealthcom. Last updated July 11, 2016. 2017. Available at: Accessed on July 26, 2017.


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