Initial investigations and diagnosis of suspected haemophilia in a child with unexplained bruising should begin with a careful clinical assessment and history to exclude non-accidental injury and other causes. If non-accidental injury is suspected, immediate referral to child protection services is required NICE CKS,NICE CG89.
If non-accidental injury is not suspected, liaise promptly with a paediatrician or paediatric haematologist to arrange non-traumatic venepuncture for blood tests. This is important to avoid further bruising or haematoma formation and to prevent activation of coagulation in samples NICE CKS.
Initial blood tests should include a full blood count, clotting screen (including activated partial thromboplastin time [aPTT] and prothrombin time [PT]), and specific clotting factor assays to identify deficiencies such as factor VIII or IX, which are diagnostic of haemophilia. Specialist tests may also include von Willebrand factor screening to exclude other bleeding disorders NICE CKS.
Children with significant active bleeding not responding to simple measures should be admitted for urgent management. For children with unexplained bruising but no signs of malignancy or other systemic illness, specialist haematology assessment is essential to confirm diagnosis and guide treatment NICE CKS.