What is psoriasis?
Watch this video as dermatologist David M. Pariser, MD, FAAD, explains why we get psoriasis and the benefits of treatment.
To watch the entire video, which includes inspiring tips from Jerry Mathers, who lives with psoriasis and is best known as the Beaver in the TV show "Leave it to Beaver," visit the Psoriasis video library. 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:
- Plaque (also called psoriasis vulgaris).
- Inverse (also called flexural psoriasis or intertriginous psoriasis).
- Erythrodermic (also called exfoliative psoriasis).
Some people get more than one type. Sometimes a person gets one type of psoriasis, and then the type of psoriasis changes.
Psoriasis: Signs and symptoms
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.
Plaque psoriasis (also called psoriasis vulgaris)
- Raised, reddish patches on the skin called plaque (plak).
- Patches may be covered with a silvery-white coating, which dermatologists call scale.
- Patches can appear anywhere on the skin.
- Most patches appear on the knees, elbows, lower back, and scalp.
- Patches can itch.
- Scratching the itchy patches often causes the patches to thicken.
- Patches vary in size and can appear as separate patches or join together to cover a large area.
- Nail problems — pits in the nails, crumbling nail, nail falls off
- Small, red spots (usually on the trunk, arms, and legs but can appear on the scalp, face, and ears).
- Spots can show up all over the skin.
- Spots often appear after an illness, especially strep throat.
- Spots may clear up in a few weeks or months without treatment.
- Spots may appear where the person had plaque psoriasis
- Skin red, swollen, and dotted with pus-filled bumps.
- Bumps usually appear only on the palms and soles.
- Soreness and pain where the bumps appear.
- Pus-filled bumps will dry, and leave behind brown dots and/or scale on 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:
- Bright-red skin.
- Been feeling sick and exhausted.
- Severe itching.
- Rapid pulse.
- Loss of appetite.
- Muscle weakness
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)
- Smooth, red patches of skin that look raw.
- Patches only develop where skin touches skin, such as the armpits, around the groin, genitals, and buttocks. Women can develop a red, raw patch under their breasts.
- Skin feels very sore where inverse psoriasis appears.
Inverse psoriasis: This type of psoriasis develops in areas where skin touches skin, such as the armpit.*
- Skin looks like it is burned.
- Most (or all) of the skin on the body turns bright red.
- Body cannot maintain its normal temperature of 98.6° F. Person gets very hot or very cold.
- Heart beats too fast.
- Intense itching.
- Intense pain.
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.**