Immune (or idiopathic) thrombocytopenic purpura (ITP) is an immune-mediated reduction in the platelet count. Antibodies are directed against the glycoprotein IIb/IIIa or Ib-V-IX complex. It is an example of a type II hypersensitivity reaction.

ITP in children is typically more acute than in adults and may follow an infection or vaccination.

More common in children ages 2-6

PC

• bruising
• petechial or purpuric rash
• bleeding is less common and typically presents as epistaxis or gingival bleeding

Investigation

• full blood count
  • should demonstrate an isolated thrombocytopenia
• blood film
• bone marrow examinations is only required if there are atypical features e.g.
  • lymph node enlargement/splenomegaly, high/low white cells
  • failure to resolve/respond to treatment

Management

• usually, no treatment is required
  • ITP resolves in around 80% of children with 6 months, with or without treatment
• advice to avoid activities that may result in trauma (e.g. team sports)
• other options may be indicated if the platelet count is very low (e.g. < 10 * 10/L) or there is significant bleeding. Options include:
  • oral/IV corticosteroid (first line)
  • IV immunoglobulins
  • platelet transfusions can be used in an emergency (e.g. active bleeding) but are only a temporary measure as they are soon destroyed by the circulating antibodies