Idiopathic or 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.