Immune thrombocytopenia (ITP) is a disorder that can lead to easy or excessive bruising and bleeding. The bleeding results from unusually low levels of platelets — the cells that help blood clot.
Formerly known as idiopathic thrombocytopenic purpura, ITP can cause purple bruises, as well as tiny reddish-purple dots that look like a rash.
Children may develop ITP after a viral infection and usually recover fully without treatment. In adults, the disorder is often long term.
If you don't have signs of bleeding and your platelet count isn't too low, you may not need any treatment. If your symptoms are more severe, treatment may include medications to boost your platelet count or surgery to remove your spleen.
Petechiae may look like a rash and usually appear in clusters. Here they appear on a leg (A) and on an abdomen (B).
Immune thrombocytopenia may have no signs and symptoms. When they do occur, they may include:
- Easy or excessive bruising
- Superficial bleeding into the skin that appears as pinpoint-sized reddish-purple spots (petechiae) that look like a rash, usually on the lower legs
- Bleeding from the gums or nose
- Blood in urine or stools
- Unusually heavy menstrual flow
When to see a doctor
Make an appointment with your doctor if you or your child develops warning signs that worry you. Bleeding that won't stop is a medical emergency. Seek immediate help if you or your child experiences bleeding that can't be controlled by the usual first-aid techniques, such as applying pressure to the area.
Immune thrombocytopenia usually happens when your immune system mistakenly attacks and destroys platelets, which are cell fragments that help blood clot. In adults, this may be triggered by infection with HIV, hepatitis or H. pylori — the type of bacteria that causes stomach ulcers. In most children with ITP, the disorder follows a viral illness, such as the mumps or the flu.
ITP is more common among young women. The risk appears to be higher in people who also have diseases such as rheumatoid arthritis, lupus and antiphospholipid syndrome.
A rare complication of immune thrombocytopenia is bleeding into the brain, which can be fatal.
If you're pregnant and your platelet count is very low or you have bleeding, you have a greater risk of heavy bleeding during delivery. Your doctor may suggest treatment to maintain a stable platelet count, taking into account the effects on your baby.