Psoriasis is a skin disease that causes itchy or sore patches of thick, red skin with silvery scales. You usually get the patches on your elbows, knees, scalp, back, face, palms and feet, but they can show up on other parts of your body. Some people who have psoriasis also get a form of arthritis called psoriatic arthritis.

A problem with your immune system causes psoriasis. In a process called cell turnover, skin cells that grow deep in your skin rise to the surface. Normally, this takes a month. In psoriasis, it happens in just days because your cells rise too fast.

Psoriasis can be hard to diagnose because it can look like other skin diseases. Your doctor might need to look at a small skin sample under a microscope.

Psoriasis can last a long time, even a lifetime. Symptoms come and go. Things that make them worse include

• Infections
• Stress
• Dry skin
• Certain medicines

Psoriasis usually occurs in adults. It sometimes runs in families. Treatments include creams, medicines, and light therapy.

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. Scientists do not fully understand what causes psoriasis, but they know that it involves a mix of genetics and environmental factors.

The symptoms of psoriasis can sometimes 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 your treatment plan will depend on the type and severity of disease. Most forms of psoriasis are mild or moderate and can be successfully treated with creams or ointments. Managing common triggers, such as stress and skin injuries, can also help keep the symptoms under control.

Having psoriasis carries the risk of getting other serious conditions, including:

• Psoriatic arthritis, a chronic form of arthritis that causes pain, swelling, and stiffness of the joints and places where tendons and ligaments attach to bones (entheses).
• Cardiovascular events, such heart attacks and strokes.
• Mental health problems, such as low self-esteem, anxiety, and depression.
• People with psoriasis may also be more likely to get certain cancers, Crohn’s disease, diabetes, metabolic syndrome, obesity, osteoporosis, uveitis (inflammation of the middle of the eye), liver disease, and kidney disease.

Psoriasis is a chronic (long-lasting) skin disease of scaling and inflammation that affects more than three percent of the U.S. population.

Although the disease occurs in all ages, it mostly affects adults. It appears about equally in males and females.

Psoriasis occurs when skin cells quickly rise from below the surface of the skin and pile up on the surface before they can mature. Usually this process (also called turnover) takes about a month, but in psoriasis it may occur in only a few days.

In its typical form, psoriasis results in patches of thick, red (inflamed) skin covered with silvery scales. These patches, which are sometimes referred to as plaques, are usually itchy or sore. Plaques often occur on the elbows, knees, other parts of the legs, scalp, lower back, face, palms, and soles of the feet. But they can occur on skin anywhere on the body.

How does psoriasis affect quality of life?

People with psoriasis may experience significant physical discomfort and some disability. Itching and pain can interfere with basic functions, such as caring for oneself, walking, and sleeping. Plaques on hands and feet can make it difficult to work in certain physical occupations, play some sports, and care for family members. People with moderate to severe psoriasis may also feel self-conscious about their appearance.

How is psoriasis diagnosed?

Because psoriasis can resemble other skin diseases, doctors sometimes find it difficult to diagnose it. Health care providers may need to use a microscope to examine a small skin sample before confirming a diagnosis.

In many cases, there is a family history of psoriasis. Researchers who have studied a large number of families affected by psoriasis have identified genes linked to the disease.

People with psoriasis may notice times when their skin worsens, called flares, before improving. Infections, stress, and weather changes can cause flares. Also, certain medicines may trigger an outbreak or worsen the disease.

How is psoriasis treated?

Doctors generally treat psoriasis in steps based on the severity of the disease, size of the areas involved, type of psoriasis, and where the psoriasis is located. Options can include:

• Medicines applied to the skin (topical treatment)
• Light treatment (phototherapy)
• Medicines by mouth or injection (systemic therapy)

Over time, affected skin can become resistant to treatment, especially when topical corticosteroids are used. Also, a treatment that works well in one person may have little effect in another. Thus, doctors often use a trial-and-error approach to find an option that works.

Topical Treatment

Treatments applied directly to the skin may improve the condition. Doctors find that some patients respond well to ointment or cream forms of corticosteroids, vitamin D3, retinoids, coal tar, or anthralin. Bath solutions and lubricants may be soothing, but they are seldom strong enough to improve the condition of the skin. Therefore, they usually are combined with stronger remedies.

Light Therapy

Natural ultraviolet (UV) light from the sun and controlled delivery of artificial UV light are used to treat psoriasis. It is important that a doctor administers light therapy. Spending too much time in the sun or a tanning bed can cause skin damage, increase the risk of skin cancer, and worsen symptoms.

Systemic Treatment

For more severe forms of psoriasis, doctors sometimes prescribe medicines that are taken by pill or injection.

• Cyclosporine. Taken orally, cyclosporine acts by suppressing the immune system to slow the rapid turnover of skin cells. It may provide a quick relief of symptoms, but the improvement stops when treatment is discontinued. Cyclosporine may impair kidney function or cause high blood pressure (hypertension). Therefore, a doctor's supervision is important.
• Methotrexate. Like cyclosporine, methotrexate suppresses the immune system to slow cell turnover. It can be taken by pill or injection. Patients taking methotrexate must be closely monitored because it can cause liver damage and decrease the production of oxygen-carrying red blood cells, infection-fighting white blood cells, and clot-enhancing platelets.
• Retinoids. Oral retinoids are compounds with vitamin A-like properties that may be prescribed for severe cases of psoriasis that do not respond to other therapies. Because these medications may cause birth defects, women must consult with their health-care provider if they plan to become pregnant.
• Biologics. Biologics are made from proteins produced by living cells instead of chemicals. They interfere with specific immune system processes, which cause the overproduction of skin cells and inflammation. These drugs are injected (sometimes by the patient). Patients need their doctors to carefully monitor these treatments.
• PDE4 inhibitors. Taken orally, phosphodiesterase 4 (PDE4) inhibitors target molecules inside immune cells to suppress the rapid turnover of skin cells and inflammation.

Combination Therapy

Combining various topical, light, and systemic treatments often permits lower doses of each and can result in greater improvements.

There are many approaches for treating psoriasis. Ask your doctor about the best options for you.

There are several different types of psoriasis. Here are a few examples:

• Plaque psoriasis, which causes patches of skin that are red at the base and covered by silvery scales.
• Guttate psoriasis, which causes small, drop-shaped lesions on your trunk, limbs and scalp. This type of psoriasis is most often triggered by upper respiratory infections, such as strep throat.
• Pustular psoriasis, which causes pus-filled blisters. Flares can be caused by medications, infections, stress, or certain chemicals.
• Inverse psoriasis, which causes smooth, red patches in folds of skin near the genitals, under the breasts or in the armpits. Rubbing and sweating can make this type of psoriasis worse.
• Erythrodermic psoriasis, which causes red and scaly skin over much of your body. This can be a reaction to a bad sunburn or taking certain medications, such as corticosteroids. It can also happen if you have a different type of psoriasis that is not well controlled. This type of psoriasis can be very serious, so if you have it, you should see a doctor immediately.

Guttate psoriasis is a skin condition in which small, red, and scaly teardrop-shaped spots appear on the arms, legs, and middle of the body. It is a relatively uncommon form of psoriasis. The condition often develops very suddenly, and is usually triggered by an infection (e.g., strep throat, bacteria infection, upper respiratory infections or other viral infections). Other triggers include injury to the skin, including cuts, burns, and insect bites, certain malarial and heart medications, stress, sunburn, and excessive alcohol consumption.

Pustular psoriasis is a rare form of psoriasis that is characterized by widespread pustules and reddish skin. This condition can occur alone or with plaque-type psoriasis. Most cases of Pustular psoriasis are thought to be ""multifactorial"" or associated with the effects of multiple genes in combination with lifestyle and environmental factors. There are several triggers for this conditions including withdrawal from corticosteroids, exposure to various medications and/or infections. Some cases of the generalized form are caused by changes in the IL36RN gene and are inherited in an autosomal recessive pattern. In severe cases, hospitalization may be required.

Generalized pustular psoriasis (GPP) is a severe form of a skin disorder called psoriasis. GPP and other forms of psoriasis are caused by abnormal inflammation. Inflammation is a normal immune system response to injury and foreign invaders (such as bacteria). However, when inflammation is abnormal and uncontrolled, it can damage the body's tissues and organs. Individuals with GPP have repeated episodes in which large areas of skin become red and inflamed and develop small pus-filled blisters (pustules). The skin problems can be accompanied by fever, extreme tiredness (fatigue), muscle weakness, an increased number of white blood cells, and other signs of inflammation throughout the body (systemic inflammation). The inflammation problems subside and reappear often. Episodes can be triggered by infection, exposure to or withdrawal from certain medications, menstruation, or pregnancy, although the trigger is often unknown. GPP can be life-threatening if not treated.

While many affected individuals have features only of GPP (called GPP alone), some develop features of another skin condition called psoriasis vulgaris (PV), either before or after GPP appears. PV, the most common form of psoriasis, is characterized by red, scaly patches of skin (plaques) on parts of the body.

Parapsoriasis describes a group of skin diseases that can be characterized by scaly patches or slightly elevated papules and/or plaques (red, scaly patches) that have a resemblance to psoriasis. Because of the variation in clinical presentation and a lack of a specific diagnostic finding on histopathology, a uniformly accepted definition of Parapsoriasis remains lacking. There are 2 general forms: a small plaque type, which is usually benign, and a large plaque type, which is a precursor of cutaneous T-cell lymphoma (CTCL).

Anyone can get psoriasis, but it is more common in adults than in children. It affects men and women equally.

Psoriasis is an immune-mediated disease, which means that your body’s immune system starts overacting and causing problems. If you have psoriasis, immune cells become active and produce molecules that set off the rapid production of skin cells. This is why skin in people with the disease is inflamed and scaly. Scientists do not fully understand what triggers the faulty immune cell activation, but they know that it involves a combination of genetics and environmental factors. Many people with psoriasis have a family history of the disease, and researchers have pinpointed some of the genes that may contribute to its development. Nearly all of them play a role in the function of the immune system.

Some external factors that may increase the chances of developing psoriasis include:

• Infections, especially streptococcal and HIV infections.
• Certain medicines, such as drugs for treating heart disease, malaria, or mental health problems.
• Smoking.
• Obesity.

Symptoms of psoriasis vary from person to person, but some common ones are:

• 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.

Some patients have a related condition called psoriatic arthritis, which is characterized by stiff, swollen, painful joints. If you have symptoms of psoriatic arthritis, it is important to see your doctor soon because this is one of the most destructive forms of arthritis.

The symptoms of psoriasis tend to come and go. You may find that there are times when your symptoms get worse, called flares, followed by times when you feel better.

To diagnose psoriasis, your doctor usually examines your skin, scalp, and nails for signs of the condition. They may also ask questions about your health and history, such as whether you:

• Experience symptoms such as itchy or burning skin.
• Had a recent illness or experienced severe stress.
• Take certain medicines.
• Have relatives with the disease.
• Experience joint tenderness.

This information will help the doctor figure out if you have psoriasis, and, if so, identify which type. To rule out other skin conditions that look like psoriasis, your doctor may take a small skin sample to examine under a microscope.

While there is currently no cure for psoriasis, there are treatments that keep symptoms under control so that you can resume daily activities and sleep better. There are different types of treatment, and your doctor will work with you to decide which is best for you, taking into consideration the type of psoriasis you have, how severe it is, where it is on your body, and the possible side effects of medications. Your treatment may include the following.

Medications

• Topical therapies. Creams, ointments, lotions, foams, or solutions, especially those containing corticosteroids, are commonly used to treat people with mild to moderate disease. Other topical therapies include vitamin D-based medicines, retinoids (related to vitamin A), coal tar, and anthralin (another tar product).
• Injected or oral therapies.
• Methotrexate. This medicine is in a class called antimetabolites, and it is available in an oral or injected form. It suppresses the immune system and slows down cell growth and division.
• Retinoids. These compounds, which are related to vitamin A, may help some people with moderate to severe psoriasis. They can be used in combination with phototherapy.
• Biologic response modifiers. These medications are injected and block specific immune molecules, helping to decrease or stop inflammation.
• Immunosuppressants. These medicines are normally used for severe cases, and they work by suppressing the immune system.
• Phosphodiesterase 4 (PDE4) inhibitors. These target enzymes inside immune cells and suppress the rapid turnover of skin cells and inflammation.

Phototherapy

This treatment involves having a doctor shine an ultraviolet light on your skin in their office. A doctor may also prescribe a home ultraviolet light unit. Phototherapy is usually used when large areas of the skin are affected by the disease.

Psoriasis is treated by:

• Dermatologists, who specialize in conditions of the skin, hair, and nails. You may want to find a dermatologist that specializes in treating psoriasis.

Other health care providers who may be involved in your care include:

• Mental health professionals, who provide counseling and treat mental health disorders, such as depression and anxiety.
• Primary health care providers, including family doctors, internists, or pediatricians.

Psoriasis can affect a person’s day-to-day life, including work and sleep. However, health care providers understand the impact of the disease and can work with you to help reduce the symptoms. In addition to going to your doctor regularly, here are some things you can do to help manage your symptoms:

• Keep your skin well moisturized. Bathe in lukewarm water and use mild soap that has added oils. After bathing, apply heavy moisturizing lotions while your skin is still damp.
• Maintain a healthy weight. Obesity makes the symptoms of psoriasis worse.
• If you smoke, work with your doctor to make a plan to quit. Studies have shown that the more a person smokes, the worse the symptoms tend to be.
• Moderate your use of alcohol. Some studies suggest that excessive alcohol consumption aggravates symptoms.
• Expose your skin to small amounts of sunlight. Limited sunlight can alleviate symptoms, but too much can make them worse, so consult your doctor for advice.
• Avoid known triggers. Try to identify things that trigger 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. The scaly patches of skin can make many people feel self-conscious about their appearance. Psoriasis can affect a person’s mental health, increasing the risk of anxiety and depression. Seeking out support can help you learn more about coping and living with the disease.

"It started as plaque psoriasis in my navel and then some plaques on my scalp," recalls LaFoy, 46, a civil engineer from Plano, Texas. "I wasn't diagnosed with psoriasis at first. It was diagnosed as dandruff and other things." A year went by before he got an accurate diagnosis.

Brian LaFoy with his wife Jennifer, and his children, Micah and Bethany.

Considering treatment options

His father's experiences with earlier psoriasis treatments led LaFoy to be wary about his own treatment options.

"They didn't know as much back then as they do now," he says. "My dad went through some medications that affected his health quite a bit, and for a period of time, almost killed him."

"That led to me stay away from anything that I would take internally, orally, or a shot," LaFoy recalls. "Everything I did for years and years was only skin creams. That's the only thing I would touch, just having seen what happened to my father. I pretty much tried every topical there was."

Quality of life issue

By the time he reached his mid-30s, LaFoy's condition had advanced to severe plaque psoriasis. He had it in his ears and on his scalp, chest, knees, feet, and other places on his body. He also started to develop symptoms of psoriatic arthritis. That is a form of arthritis that produces the joint inflammation common in arthritis and the lesions common in psoriasis.

"It became a quality of life issue for me," LaFoy says. "I'd lost the use of my right hand because the arthritis was so bad. That's the point where I decided to go on biologics. I've been taking etanercept for about eight years. It's a once-a-week injection for me. I have cleared up approximately 95 percent and am living manageably with my psoriasis now. It still hurts every day and I still have plaques on certain parts of my body. But I'm much better than I was before I started on biologics."

Today LaFoy is active with the National Psoriasis Foundation and a national mentor for psoriasis patients.

What advice does he offer to those with the disease?

"Understand your body and try to get the right help at the right time as early as you can," he advises. "It can be such a long time for a lot of patients to be able to get the proper diagnosis. There's a limited number of doctors who really specialize in it. Fortunately, I'm with one now."

LaFoy, who has his own family now, has not allowed psoriasis to slow down his active lifestyle. He plays soccer and ice hockey, and enjoys snowboarding, wakeboarding, and scuba diving. However, he says his true passion is surfing and he spends as much time as he can on the Florida and California coasts.

"The key is to not let the disease get you. Part of who I am is being active and doing things I like to do. Whatever it takes, that's what I'm willing to do. I'm one of the lucky ones."

You may have heard of psoriasis, but do you know what it is? Psoriasis is a long-term, or chronic, skin disorder that affects more than 6.7 million U.S. adults. Symptoms can vary, but it’s usually recognized by itchy or sore patches of thick, red skin with silvery scales. There’s currently no cure, but treatment often helps.

Psoriasis occurs when skin cells quickly rise to the surface of the skin and build up into thick patches, or plaques. Ordinarily, skin cells mature as they rise from their origins below the surface of the skin. In psoriasis, these cells pile up before they’ve had a chance to properly mature.

Psoriasis actually begins in the immune system, which normally protects the body against infection and disease. In psoriasis, the immune system becomes misdirected and overactive. This can cause redness and swelling (inflammation) and lead to the rapid buildup of skin cells.

Plaques are most often found on the elbows, knees, or scalp. But they can also affect the face, fingernails, toenails, soft tissues of the genitals, or any skin-covered region.

“Patients can have a lot of symptoms like itching, cracking, and bleeding that can disrupt their sleep and their social relationships,” says Dr. Joel Gelfand, a skin specialist (dermatologist) at the University of Pennsylvania. People with moderate to severe psoriasis may feel self-conscious or have a poor self-image, which can lead to depression or social isolation.

Some people with psoriasis also experience joint inflammation that produces arthritis-like pain. This condition is called psoriatic arthritis. Gelfand and other NIH-supported researchers have found that psoriasis—especially severe psoriasis—is linked to certain other disorders as well, such as heart conditions, obesity, high blood pressure, and diabetes.

Psoriasis can occur at any age, but it typically first appears in young adulthood. Many people with psoriasis have a family history of the disorder. Researchers have been able to identify certain genes linked to the disease, but they still don’t fully understand the disease process. They do know that it isn’t contagious. You can’t “catch” psoriasis by touching someone who has it.

Psoriasis can be hard to diagnose, because it can look like other skin diseases. Your doctor might need to look at a small skin sample under a microscope. It’s often best to make an appointment with a primary care doctor or a dermatologist to get an accurate diagnosis.

There are many approaches for treating psoriasis. Safe and proven treatment options include creams, light therapy, and medications given as pills or a shot.

“Treatment decisions in psoriasis need to be highly individualized and tailored toward the patient’s clinical condition and underlying health status, as well as their preferences and goals,” Gelfand says. Be sure to ask your doctor about the best treatment options for you.

Psoriasis symptoms may briefly worsen, or flare. These flares can arise when people are stressed or experience a traumatic event like the death of a family member or friend. Smoking, heavy alcohol use, and being overweight can also aggravate psoriasis. See the “Wise Choices” box for tips on avoiding flares.

Gelfand and other NIH-funded researchers have been working to develop better therapies. “It’s a great time to be hopeful and optimistic about this disease,” Gelfand says. “Most of the therapies coming out now seem to be well-tolerated and have impressive effectiveness.”

Avoid Psoriasis Triggers

Factors that may trigger psoriasis or make it worse include:

• physical and emotional stress.
• injury to the skin such as cuts or burns.
• infections, especially strep throat.
• cold weather.
• smoking or heavy alcohol use.