Immune Thrombocytopenia (ITP) in Children
Immune Thrombocytopenia (ITP) is a common cause of isolated thrombocytopenia in young children, typically between the ages of 2 and 6. It’s an acquired autoimmune disorder characterised by the destruction of platelets, which are a vital component of blood clotting. The destruction is mediated by autoantibodies, usually IgG, that target the platelets. ITP is often a benign, self-limiting condition, but due to the risk of significant bleeding, it requires a careful assessment and management strategy.
Aetiology and Clinical Presentation
Aetiology: ITP is frequently triggered by a preceding viral infection (such as varicella or a viral upper respiratory tract infection) or, less commonly, a vaccination.
Clinical Features: The presentation is a result of low platelet count, leading to bleeding.
Petechiae: Small, pinpoint red or purple spots on the skin.
Purpura: Larger purple patches on the skin.
Mucosal Bleeding: Nosebleeds (epistaxis) and bleeding gums are common.
Bruises: Easy bruising is often the presenting complaint.
Red Flags: A thorough history should be taken to exclude other, more serious causes of thrombocytopenia. Red flags include fever, weight loss, night sweats, bone pain, or a history of chronic illness.
Diagnosis and Investigations
The diagnosis of ITP is one of exclusion. It’s crucial to rule out other causes of thrombocytopenia, such as leukaemia.
Initial Tests:
Full Blood Count (FBC) and a manual blood film are essential. In ITP, the platelet count is usually severely low (often /L), while the red blood cell and white blood cell counts are normal.
Discussion with a Haematologist: A bone marrow aspiration is usually not required for a typical, isolated ITP presentation. However, it should be considered and discussed with a haematologist if there are any red flags, such as:
Severe anaemia or neutropenia.
Hepatosplenomegaly (enlarged liver and spleen).
Lymphadenopathy (enlarged lymph nodes).
Other systemic symptoms like a limp or significant fatigue.
Management
Management of ITP is based on the severity of bleeding rather than just the platelet count.
Education and Monitoring:
Educate the family about the condition and reassure them of its generally benign nature.
Advise the child to avoid contact sports and activities that may cause injury.
Avoid medications that can affect platelet function, such as non-steroidal anti-inflammatory drugs (NSAIDs).
Pharmacological Interventions:
No Treatment: Most children with mild or no bleeding do not require any treatment and are managed with observation and safety advice.
First-line Treatment for Significant Bleeding: If there is significant or life-threatening bleeding, first-line treatments are intravenous immunoglobulin (IVIG) or corticosteroids (e.g., methylprednisolone) to reduce the immune-mediated destruction of platelets.
Tranexamic Acid: This can be used for small mucosal bleeds like nosebleeds.
Chronic ITP: ITP is considered chronic if the thrombocytopenia persists for more than 12 months. This is more common in older children (>10 years) and females. Chronic ITP may require ongoing management, and in very rare, severe cases, a splenectomy may be considered, but this is a last resort.