Bruising, coagulation disorder, and physical child abuse.

Child protection is a priority, and the medical community has a responsibility to detect cases of abuse and to intervene using the appropriate measures. Bruises are the most common manifestation of physical abuse, although their interpretation can be extremely challenging for paediatricians as the evidence base is limited. As a history of abuse is a strong risk factor for further non-accidental injury, a correct diagnosis is vital. Clearly, the diagnostic process must determine whether an underlying coagulation disorder exists. It is important to realize, however, that the presence of a coagulation deficit does not necessarily exclude abuse. A growing body of evidence suggests that the practice of estimating bruise age is unreliable; therefore, a key factor in diagnosing abuse is the pattern of bruise distribution, which must be linked to the child's history and stage of development. The paediatrician must also consider the combined probabilities of individual bruises being due to abuse. Our scoring system, which uses a Bayesian approach to evaluate these probabilities and assess bruising patterns, is a potentially useful tool for discriminating between abused and non-abused children. We recommend that paediatricians and haematologists should work together to reach a diagnostic consensus that is acceptable in both the clinic and a court of law.