Psoriasis is a chronic autoimmune condition that causes the rapid buildup of your skin cells. This buildup of cells causes scaling on your skin’s surface.
Inflammation and redness around the scales are fairly common. Typical psoriatic scales are whitish-silver and develop in thick, red patches. However, on darker skin tones, they can also appear more purplish, dark brown with gray scales. Sometimes, these patches will crack and bleed.
Psoriasis is the result of a sped-up skin production process. Typically, skin cells grow deep in your skin and slowly rise to the surface. Eventually, they fall off. The typical life cycle of a skin cell is 1 month.
In people with psoriasis, this production process may occur in just a few days. Because of this, skin cells don’t have time to fall off. This rapid overproduction leads to the buildup of skin cells.
According to one Trusted Source published in 2021, around 7.5 million American adults ages 20 and older have psoriasis — a 3% prevalence rate (occurrence of a condition). By race and ethnicity, the prevalence rates are:
Scales typically develop on joints, such as elbows and knees. However, they may develop anywhere on your body, including the:
Less common types of psoriasis affect the:
It’s commonly associated with several other conditions, including:
There are five types of psoriasis:
Plaque psoriasis is the most common type of psoriasis.
The American Academy of Dermatology (AAD) estimates that about 80–90% of people with the condition have plaque psoriasis. It causes red, inflamed patches on light skin tones and purple or grayish color or darker brown patches on skin of color — making it harder to diagnose in people of color.
These patches are often covered with whitish-silver scales or plaques and are often more severe on skin of colorTrusted Source. These plaques are commonly found on the elbows, knees, and scalp.
Guttate psoriasis commonly occurs in childhood. This type of psoriasis causes small pink or violet spots. The most common sites for guttate psoriasis include your torso, arms, and legs. These spots are rarely thick or raised like plaque psoriasis.
Pustular psoriasis is more common in adults. It causes white, pus-filled blisters and broad areas of red or violet —depending on skin tone — inflamed skin. It can appear as a more intense violet color on darker skin tones. Pustular psoriasis is typically localized to smaller areas of your body, such as the hands or feet, but it can be widespread.
Inverse psoriasis causes bright areas of red, shiny, inflamed skin. Patches of inverse psoriasis develop under your armpits or breasts, in your groin, or around skinfolds in your genitals.
Erythrodermic psoriasis is a severe and very rare type of psoriasis, according to the National Psoriasis Foundation.
This form often covers large sections of your body at once. The skin almost appears sunburned. Scales that develop often slough off in large sections or sheets. It’s not uncommon for you to run a fever or become very ill with this form of psoriasis.
This type can be life threatening, so it’s important that you make an appointment with a healthcare professional immediately.
Psoriasis symptoms differ from person to person and depend on the type of psoriasis you have. Areas of psoriasis can be as small as a few flakes on your scalp or elbow, or cover the majority of your body.
The most common symptoms of plaque psoriasis include:
Not every person will experience all these symptoms. Some people will experience entirely different symptoms if they have a less common type of psoriasis.
Most people with psoriasis go through “cycles” of symptoms. The condition may cause severe symptoms for a few days or weeks, and then the symptoms may clear up and be almost unnoticeable.
Then, in a few weeks or if made worse by a common psoriasis trigger, the condition may flare up again. Sometimes, symptoms of psoriasis disappear completely.
When you have no active signs of the condition, you may be in “remission.” That does not mean psoriasis will not come back, but for this period of time, you’re symptom-free.
Psoriasis is not contagious. You cannot pass the skin condition from one person to another. Touching a psoriatic lesion on another person will not cause you to develop the condition.
It’s important to be educated on the condition, as many people think psoriasis is contagious.
Doctors are unclear as to what causes psoriasis. However, thanks to decades of research, they have a general idea of two key factors:
Psoriasis is an autoimmune condition. Autoimmune conditions are the result of your body attacking itself. In the case of psoriasis, white blood cells known as T cells mistakenly attack your skin cells.
Generally, in the body, white blood cells are deployed to attack and destroy invading bacteria and mount a defense against infections. This mistaken autoimmune attack causes the skin cell production process to go into overdrive. The sped-up skin cell production causes new skin cells to develop too quickly. They are pushed to the skin’s surface, where they pile up.
This results in the plaques that are most commonly associated with psoriasis. The attacks on the skin cells also cause red, inflamed areas of skin to develop.
Some people inherit genes that make them more likely to develop psoriasis. If you have an immediate family member with the skin condition, you are at an increased riskTrusted Source of developing psoriasis, according to research published in 2019.
Read more about the causes of psoriasis.
Two tests or examinations may be necessary to diagnose psoriasis.
Most doctors can make a diagnosis with a simple physical exam. Symptoms of psoriasis are typically evident and easy to distinguish from other conditions that may cause similar symptoms.
During this exam, be sure to show your doctor all areas of concern. In addition, let your doctor know if any family members have the condition.
If your symptoms are unclear, or if your doctor wants to confirm their suspected diagnosis, they may take a small sample of your skin. This is known as a biopsy.
Biopsies can be done in your doctor’s office on the day of your appointment. Your doctor will likely inject a local numbing medication to make the biopsy less painful.
They will then send the skin biopsy to a lab for analysis, where it’ll be examined under a microscope. The examination can diagnose the type of psoriasis you have. It can also rule out other possible disorders or infections.
When the results return, your doctor may request an appointment to discuss the findings and treatment options with you.
External “triggers” may start a new bout of psoriasis. These triggers are not the same for everyone. They may also change over time for you.
The most common triggers for psoriasis include:
Unusually high stress may trigger a flare-up. If you learn to reduce and manage your stress, you can reduce and possibly prevent flare-ups.
Alcohol use disorder can trigger psoriasis flare-ups. If you drink excessively, psoriasis outbreaks may be more frequent. Considering reducing alcohol consumption or quitting is helpful for more than just your skin. Your doctor can help you create a plan to address your alcohol use concerns if you need assistance.
An accident, cut, or scrape may trigger a flare-up. Injections, vaccines, and sunburns can also trigger a new outbreak.
Some medications are considered psoriasis triggers. These medications include:
Psoriasis is caused, at least in part, by the immune system mistakenly attacking healthy skin cells. If you’re sick — maybe you have an infection — your immune system can mistakenly build an immune response against itself in addition to the necessary defense against the infection.
This might start another psoriasis flare-up. Strep throat is a common trigger.
Psoriasis has no cure. Treatments aim to:
Psoriasis treatments fall into three categories:
Creams and ointments applied directly to the skin can be helpful for reducing mild to moderate psoriasis.
Topical psoriasis treatments include:
People with moderate to severe psoriasis, and those who have not responded well to other treatment types, may need to use oral or injected medications.
Many of these medications can have severe side effects, and for that reason, doctors usually prescribe them for short periods of time.
These medications include:
This psoriasis treatment uses ultraviolet (UV) or natural light. Sunlight kills the overactive white blood cells that are attacking healthy skin cells and causing the rapid cell growth. Both UVA and UVB light may be helpful in reducing symptoms of mild to moderate psoriasis.
Most people with moderate to severe psoriasis will benefit from a combination of treatments. This type of therapy uses more than one of the treatment types to reduce symptoms. Some people may use the same treatment their entire lives. Others may need to change treatments occasionally if their skin stops responding to the treatment they’re receiving.
Learn more about your treatment options for psoriasis.
If you have moderate to severe psoriasis — or if psoriasis stops responding to other treatments — your doctor may consider an oral or injected medication.
The most common oral and injected medications used to treat psoriasis include:
This class of medications alters your immune system and prevents interactions between your immune system and inflammatory pathways. These medications are injected or given through intravenous (IV) infusion.
Retinoids reduce skin cell production. Once you stop using them, symptoms of psoriasis will likely return. Side effects include hair loss and mucosal dryness.
People who are pregnant or may become pregnant within the next 3 years should not take retinoids because of the risk of possible birth defects in unborn children.
Cyclosporine (Sandimmune) decreases the immune system’s response. This can ease symptoms of psoriasis. It also means you have a weakened immune system, so you may become sick more easily. Potential side effects include kidney problems and high blood pressure.
Like cyclosporine, methotrexate suppresses the immune system. It may cause fewer side effects when used in low doses. It can cause serious side effects long term and is not suitable during pregnancy. Serious side effects include liver damage and reduced production of red and white blood cells.