Psoriasis is a chronic autoimmune condition that causes the rapid buildup of skin cells. This buildup of cells causes scaling on the skin’s surface.
Inflammation and redness around the scales is fairly common. Typical psoriatic scales are whitish-silver and develop in thick, red patches. Sometimes, these patches will crack and bleed.
Psoriasis is the result of a sped-up skin production process. Typically, skin cells grow deep in the skin and slowly rise to the surface. Eventually, they fall off. The typical life cycle of a skin cell is one 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.
Scales typically develop on joints, such elbows and knees. They may develop anywhere on the body, including the:
Less common types of psoriasis affect the nails, the mouth, and the area around genitals.
According to one study, around 7.4 million Americans have psoriasis. 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 percent of people with the condition have plaque psoriasis. It causes red, inflamed patches that cover areas of the skin. These patches are often covered with whitish-silver scales or plaques. These plaques are commonly found on the elbows, knees, and scalp.
Guttate psoriasis is common in childhood. This type of psoriasis causes small pink spots. The most common sites for guttate psoriasis include the 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, inflamed skin. Pustular psoriasis is typically localized to smaller areas of the 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 armpits or breasts, in the groin, or around skinfolds in the genitals.
This form often covers large sections of the body at once. The skin almost appears sunburned. Scales that develop often slough off in large sections or sheets. It’s not uncommon for a person with this type of psoriasis to run a fever or become very ill.
This type can be life-threatening, so individuals should see a doctor immediately.
Psoriasis symptoms differ from person to person and depend on the type of psoriasis. Areas of psoriasis can be as small as a few flakes on the scalp or elbow, or cover the majority of the body.
The most common symptoms of plaque psoriasis include:
- red, raised, inflamed patches of skin
- whitish-silver scales or plaques on the red patches
- dry skin that may crack and bleed
- soreness around patches
- itching and burning sensations around patches
- thick, pitted nails
- painful, swollen joints
Not every person will experience all of 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 doesn’t mean psoriasis won’t come back, but for now you’re symptom-free.
Psoriasis isn’t contagious. You can’t pass the skin condition from one person to another. Touching a psoriatic lesion on another person won’t cause you to develop the condition.
Doctors are unclear as to what causes psoriasis. However, thanks to decades of research, they have a general idea of two key factors: genetics and the immune system.
Psoriasis is an autoimmune condition. Autoimmune conditions are the result of the body attacking itself. In the case of psoriasis, white blood cells known as T cells mistakenly attack the skin cells.
In a typical body, white blood cells are deployed to attack and destroy invading bacteria and fight infections. This mistaken 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, your risk for developing psoriasis is higher. However, the percentage of people who have psoriasis and a genetic predisposition is small. Approximately 2 to 3 percent of people with the gene develop the condition, according to the National Psoriasis Foundation (NPF).
Two tests or examinations may be necessary to diagnose psoriasis.
Most doctors are able to 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 the symptoms are unclear or if your doctor wants to confirm their suspected diagnosis, they may take a small sample of skin. This is known as a biopsy.
The skin will be sent to a lab, 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.
Most biopsies are done in your doctor’s office 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 biopsy to a lab for analysis.
When the results return, your doctor may request an appointment to discuss the findings and treatment options with you.