Signs and symptoms
Often, low platelet counts are picked up by coincidence when a full blood count has been ordered for routine testing. Occasionally, ITP patients suffer from bruising, nosebleeds, and bleeding gums. This normally does not occur unless the platelet count is very low (10,000 per mm3).
Low platelet count can be a feature of a large number of diseases and, when serious, warrants investigation by a haematology. In many cases, the cause is not really idiopathic but autoimmune, although antibodies against platelets are only detected in a minority.
Mild ITP does not require treatment. When platelet counts fall under 10,000 per milliliter, or under 50,000 when hemorrhage occurs (e.g. in the digestive tract or in a severe nosebleed) treatment is generally initiated with steroids, and later with so-called steroid-sparing agents (alternatively called DMARDs). When these strategies fail, splenectomy (removal of the spleen) is often undertaken, as platelets targeted for destruction will often meet their fate in the spleen. A relatively new strategy is treatment with anti-D, an agent used in mothers who have been sensitised to rhesus antigen by a Rh+ baby. Extreme cases (very rare, especially rare in children) may require vincristine, a chemotherapy agent, to stop the immune system from destroying platelets.