ACW Lee, ESK Ma

Abstract

Children who have been physically abused or victims of Munchausen syndrome by proxy may occasionally be complicated by coagulopathy. Specific bleeding diathesis presenting as suspected child abuse is rarely reported in the medical literature. More commonly, however, screening tests are used to exclude an underlying bleeding tendency in suspected cases of child abuse. Under most circumstances, ordering a platelet count, prothrombin time and activated partial thromboplastin time would be sufficient for clinical differential diagnosis or medico-legal purposes. Bleeding time may be included if a platelet function defect is suspected. However, the value of a thorough history and comprehensive physical examination cannot be overemphasized. The identification of a bleeding tendency does not exclude child abuse. A maltreated child who presents with bruises that are clearly indicative of an inflicted injury does not require coagulation screening unless indicated otherwise.

Introduction

In Tuen Mun Hospital, an average of more than one child are admitted every week for evaluation of child abuse.¹ Over 50% of these children are admitted because of suspicion of physical abuse, either alone or in association with other forms of maltreatment such as neglect, sexual or psychological abuse.² Bruises or haematomas, the cutaneous manifestation of extravasated red cells from damaged blood vessels, are the most noticeable sign of non-accidental injury. The injury may be produced from force, with or without the use of an instrument, from heat, or from intoxication. In the majority of cases, the diagnosis of physical abuse is obvious from the clinical history and physical findings.³

In the evaluation of suspected physical abuse when cutaneous bruises are the major clinical features, the major differential diagnosis is to distinguish inflicted injury from unintentional trauma. Because of the occasional reports that children with bleeding tendency may be confused with victims of child abuse, clinical evaluation becomes necessary whenever there is a suspicion of an underlying medical problem. Screening studies for coagulation and bleeding diathesis are therefore required for a number of reasons.⁴ (1) The caretaker often alleges a history that the victim bruises easily. (2) A medico-legal documentation is required when the cause of bruises is not apparent. (3) Bleeding diathesis may just be one of the manifestations of maltreatment . (4) The history or physical finding suggests an underlying coagulopathy. However, not all physically abused children require coagulation screening.

The present review will be devoted to the discussion of the basic approach on handling the issue of coagulation disorder among children with suspected maltreatment, the use of coagulation screening, and a review of bleeding disorders mistaken as child abuse in the medical literature.

The Basic Approach on the Use of Coagulation Screening

The principle underlying the clinical approach on the use of coagulation screening in a suspected case of child abuse is similar to other children.⁵ A thoroughly taken history would give clues to whether the child has any manifestations of bleeding tendency (Table 1). An underlying bleeding diathesis would be extremely unlikely if the patient has undergone surgery without excessive, prolonged or delayed haemorrhage. Operations that are commonly encountered in childhood include circumcision, tonsillectomy, dental extraction and appendicectomy. An uncomplicated craniotomy for removal of blood clots without haemostatic replacement therapy practically excludes any significant coagulopathy.

The evaluation of a child referred for suspected abuse should always include a comprehensive physical examination.⁶ In particular, the distribution, discoloration, size, shapes, and surrounding soft tissue injuries of all bruises or haematoma should be noted. Scars from previous injuries are often helpful clues. Congenital pigmented lesions such as Mongolian spots can be easily differentiated from bruises.⁷ However, confusion may arise if they occur in the limbs in isolation or when the child is not adequately exposed. Diseases with vasculitis (e.g. Henoch Schonlein purpura⁸) or vascular fragility (e.g. Ehlers-Danlos syndrome⁹) may also present with bruises. The purpuric rash associated with Henoch Schonlein purpura has a characteristic dependent distribution and papular appearance, and pat ients with Ehlers-Danlos syndrome can be distinguished by other associated features such as hyperextensibility and paper tissue scars.

Many of the inflicted injuries produce characteristic patterns that are indicative of the mode of injury.⁶ These patterns may be modified according to the amount of force used, the actual direction of the impact, and the contour of the region of the body being hit. Slapping and hitting with a stick or a rod will leave parallel tracks of bruises. These tracks of bruises occur on both sides of, rather than the actual point of, impact as it is those parts of the skin that are subjected to maximal tensile forces. Beating with a loop of electric cord or a clothes hanger will produce curved or curvilinear marks that correspond to the shape of the weapon. Also, telltale signs of bruising can be found after beating with a belt depending on whether the child is injured by the buckle or the leather strap. When such patterned bruises are evident on examination, they are clear signs of inflicted injury. Coagulation screening is not indicated unless there are suggestive clues from the history.

Even when the bruises are not typical of a recognized pattern, the older child can often tell how the injuries were sustained when asked. Sometimes the perpetrator may admit his beating and confirm the child's account of injury. If this information is available, coagulation screening may be omitted. However, when the abuser or the victim is not willing to disclose, or when a legal procedure is probable, screening for bleeding tendency will be indicated.⁴

Screening for Bleeding Tendency

The purpose of conducting coagulation screening in suspected cases of child abuse is to detect any significant bleeding diathesis as suggested by the history or physical examination, and to exclude common illnesses that may be confused with non-accidental injury. The tests are directed at both the intrinsic and extrinsic pathways of the coagulation cascade and platelet haemostasis. Complete blood count s (CBC) including platelet count, prothrombin time (PT), and activated partial thromboplastin time (APTT) are recommended as the first screening tests.^10,11 Liver and renal function tests, and measurement of bleeding time (BT) are useful if indicated. Thrombocytopenia, common coagulopathies such as haemophilia A or B, and vitamin K deficiency bleeding are easily ruled in or ruled out. Von Willebrand disease, estimated to be present in 1% of the population, can be detected by a prolongation of APTT and/or the bleeding time. More specific assays such as ristocetin cofactor and factor VIII coagulant activities are required to confirm the diagnosis. Measurement of bleeding time may also be indicated if there are other concerns of qualitative platelet disorders. These may be congenital as in the case of Glanzmann's thrombasthenia, or may be acquired in the case of salicylate ingestion. Examination of platelet size and morphology, platelet function tests, and analysis of platelet glycoproteins will be required for confirmation. The use of laboratory tests in this regard is summarized in Table 2. Specific reference describing the use of each of the laboratory test is available.¹²

When the CBC, PT, APTT and BT are normal and a bleeding diathesis is strongly suspected because of recurrent significant bleeding and/or a positive family history, further evaluation for deficiencies of factor XIII, α₂ antiplasmin or plasminogen activator inhibitor type 1 should be pursed.⁵ The clinical and laboratory features of these disorders are summarized in Table 3.

Bleeding Disorders Presenting as Suspected Physical Abuse

Bleeding disorders may occasionally be confused with child abuse, but they rarely masquerade as child maltreatment to the experienced paediatrician (Table 4). In a series of 2,578 cases evaluated by the child abuse team in Leeds, only five (0.2%) children were found to have coagulopathies including idiopathic thrombocytopenic purpura, haemophilia A, and vitamin K deficiency bleeding of the newborn.¹³ Single cases of Glanzmann's thrombasthenia, haemophilia A, and acquired inhibitors to factors VIII and IX were reported in which the affected children were initially thought to be victims of child abuse.^14,15 However, the clinical histories and physical findings in these cases were sufficiently indicative of the underlying bleeding diathesis. Specific tests that followed led to the correct diagnosis.

In a review of conditions mistaken for child abuse, Bays quoted another seven examples of "occult" coagulopathies including haemophilia, acute lymphoblastic leukaemia, rodenticide-induced coagulopathy, two cases of vitamin K deficiency secondary to cystic fibrosis, and two cases of disseminated intravascular coagulation complicating meningitis.¹⁰ Harley also reported recently two cases of idiopathic thrombocytopenic purpura and one case of haemophilia B who were initially though to have been maltreated.¹⁶ Although the history might be non-specific in some of these cases, the coagulation screening as suggested in the previous discussion was sufficient to pick up these abnormalities.

It should be emphasized that the finding of a coagulation defect does not exclude the diagnosis of child abuse. Prolongation of PT or APTT is not uncommon among victims of the shaken baby syndrome, presumably as a complication of the underlying brain injury. Of 101 children with parenchymal brain injury studied by Hymel et al.,¹⁷ 54% had mild prolongation of PT, and 24% had prolongation of APTT. Deliberate poisoning with rodenticide (superwarfarin) has been reported as Munchausen syndrome by proxy.¹⁸ However, malicious intent may be difficult to prove in extremely unkempt living environment.¹⁹ In their elegant study of 50 children with suspected abuse, O'Hara and Eden found mild, transient abnormalities of coagulation in five cases. They also diagnosed platelet aggregat ion disorder and von Willebrand disease in two other patients, respectively. However, the diagnosis of physical abuse was obvious from the history and social enquiry in these children in spite of the coagulation defect.¹⁵

Summary

It is important for the paediatrician handling suspected cases of child abuse to recognize the occasional patient with an underlying bleeding diathesis. It is equally important that a bleeding tendency be reasonably excluded when the occurrence of bleeding is unexplained. Every child who is a suspected victim of child maltreatment should have a thorough history and detailed physical examination to delineate the account and characteristics of the injuries. In this respect, the general paediatrician is well qualified to handle these children in their practice. Laboratory investigations should be used judiciously and haematologist should be consulted when there are uncertainties in the use or interpretation of tests. It should be recapitulated that physical child abuse is often a clinical diagnosis. The finding of a coagulation abnormality is by no means exclusive of an abusive incident.

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