Psoriasis (sore-EYE-ah-sis) is a chronic (long-lasting) disease. It develops when a person’s immune system sends faulty signals that tell skin cells to grow too quickly. New skin cells form in days rather than weeks.
The body does not shed these excess skin cells. The skin cells pile up on the surface of the skin, causing patches of psoriasis to appear. Psoriasis may look contagious, but it's not.
You cannot get psoriasis from touching someone who has it. To get psoriasis, a person must inherit the genes that cause it.
Types of psoriasis
If you have psoriasis, you will have one or more of these types:
Some people get more than one type. Sometimes a person gets one type of psoriasis, and then the type of psoriasis changes.
What you see and feel depends on the type of psoriasis you have. You may have just a few of the signs and symptoms listed below, or you may have many.
(also called psoriasis vulgaris)
Plaque psoriasis: This type of psoriasis often causes thick patches of skin that are covered with silvery-white scale.
Guttate psoriasis: This type of psoriasis causes small spots that can show up all over the skin.
If pus-filled bumps appear all over the body, get the person to a hospital right away. The person’s life may be in danger.
When pus-filled bumps cover the body, the person also may have:
Pustular psoriasis: This type of psoriasis causes pus-filled bumps that usually appear on the foot or hand.
(also called flexural psoriasis or intertriginous psoriasis)
Inverse psoriasis: This type of psoriasis develops in areas where skin touches skin, such as the armpit.
(also called exfoliative psoriasis)
If it looks like a person has erythrodermic psoriasis, get the person to a hospital right away. The person’s life may be in danger.
Erythrodermic psoriasis: This type of psoriasis can cause the skin to look like it is badly burned
Who gets psoriasis?
People who get psoriasis usually have one or more person in their family who has psoriasis. Not everyone who has a family member with psoriasis will get psoriasis. But psoriasis is common. In the United States, about 7.5 million people have psoriasis. Most people, about 80%, have plaque psoriasis.
Psoriasis can begin at any age. Most people get psoriasis between 15 and 30 years of age. By age 40, most people who will get psoriasis, about 75%, have psoriasis. Another common time for psoriasis to begin is between 50 and 60 years of age.
Whites get psoriasis more often than other races.
Infants and young children are more likely to get inverse psoriasis and guttate psoriasis.
What causes psoriasis?
Scientists are still trying to learn everything that happens inside the body to cause psoriasis. We know that psoriasis is not contagious.
You cannot get psoriasis from touching someone who has psoriasis.
You cannot get psoriasis from swimming in the same pool or having sex.
Scientists have learned that a person’s immune system and genes play important roles. It seems that many genes must interact to cause psoriasis.
Scientists also know that not everyone who inherits the genes for psoriasis will get psoriasis. It seems that a person must inherit the “right” mix of genes. Then the person must be exposed to a trigger.
Many people say that their psoriasis began after they experienced one of these common psoriasis triggers:
How does a dermatologist diagnose psoriasis?
To diagnose psoriasis, a dermatologist:
Sometimes a dermatologist also removes a bit of skin. A dermatologist may call this confirming the diagnosis. By looking at the removed skin under a microscope, one can confirm whether a person has psoriasis.
How do dermatologists treat psoriasis?
Treating psoriasis has benefits. Treatment can reduce signs and symptoms of psoriasis, which usually makes a person feel better. With treatment, some people see their skin completely clear. Treatment can even improve a person's quality of life.
Studies show that as psoriasis clears, a person's quality of life improves.
Thanks to ongoing research, there are many treatments for psoriasis. It is important to work with a dermatologist to find treatment that works for you and fits your lifestyle. Every treatment has benefits, drawbacks, and possible side effects.
Before you see a dermatologist for treatment, it helps to know about the treatment options. This knowledge will help you work with your dermatologist to create a treatment plan that is right for you.
You can learn about the many treatments for psoriasis by visiting the Academy’s website:
Psoriasis is a chronic (long-lasting) disease of the immune system. It cannot be cured. This means that most people have psoriasis for life. By teaming up with a dermatologist who treats psoriasis, you can find a treatment plan that works for you.
Dermatologists encourage their patients who have psoriasis to take an active role in managing this disease. By taking an active role, you can reduce the effects that psoriasis has on your quality of life.
Psoriasis is a long-lasting disease. Here are some things you can do that will help you take control.