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.
What causes psoriasis?
- 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:
- A stressful event
- Strep throat
- Taking certain medicines, such as lithium or medicine to prevent malaria
- Cold, dry weather
- A cut, scratch or bad sunburn.
- 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.
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
- 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.
- 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.