16.2 Abnormal bleeding and clotting
Bleeding disorders range from those that are severe and potentially life-threatening through to mild disorders that may be difficult to distinguish from normal.
Abnormal bleeding is the result of a disorder of one of the following:
Clinical approach to diagnosis
As a general rule, history-taking, physical examination and a small number of relatively simple laboratory tests will find most causes of abnormal bleeding. The history, with particular reference to the past and family history, will usually provide the most valuable information.
Bleeding disorder assessment
• History to determine normal from abnormal is the most valuable tool.
• Simple coagulation tests such as platelet count, activated partial thromboplastin time (aPTT), prothrombin time (PT/international normalized ratio (INR)) and fibrinogen will confirm the majority of diagnoses.
• Mucosal bleeding needs assessment for von Willebrand disorder.
History
What is abnormal?
The main question to answer in the history is whether the bleeding symptoms are within or outside normal limits. Isolated bruises over the shins are common, whereas spontaneous petechiae are abnormal. Finger-induced epistaxis is common and not indicative of a bleeding disorder; however, recurrent nose bleeds lasting for more than 10 minutes or leading to anaemia are often related to a bleeding disorder. Table 16.2.1 gives some clinical guidance.
When did the bleeding start?
Prenatal and neonatal
• Congenital infection may result in a bleeding disorder.
• Mucosal bleeding occurs with haemorrhagic disease of the newborn.
• Umbilical stump bleeding is associated with factor XIII deficiency and dysfibrinogenaemias.
• Intracranial haemorrhage may occur with factor deficiencies and with neonatal alloimmune thrombocytopenia.
• Prolonged bleeding following circumcision is suggestive of haemophilia and may be the presenting feature of haemorrhagic disease of the newborn.
Sudden onset
• Usually indicates an acute problem such as immune thrombocytopenic purpura.
• Non-accidental injury may have a haemorrhagic presentation with inadequate explanations for each specific bruise, which may have an unusual distribution (see Chapter 3.9). Skeletal trauma and other stigmata of non-accidental injury may be present.
Where is the bleeding?
Specific bleeding sites have characteristic associations:
• Joint bleeding: haemophilia A and B
• Nasal mucosa: local irritation; von Willebrand disorder and platelet dysfunction
• Gums, periosteum, skin: scurvy
• Gastrointestinal: haemorrhagic disease of the newborn in babies; liver disease in older children
• Retro-orbital: haematological malignancy or disseminated solid tumour.
What is the context of bleeding?
Family history
Haemophilia A and B are X-linked; most von Willebrand disorder subtypes and haemorrhagic hereditary telangiectasia are recessive and several platelet function disorders are dominantly inherited. Clinical penetrance in haemophilia carriers and von Willebrand disorder may be variable. It is important to review whether the family has a history of bleeding complicating surgical challenges and it may be helpful to explore any history of menorrhagia in family members.
Other aspects of history
Easy bruising, bruising at abnormal sites, prolonged bleeding following trivial trauma or bleeding following surgery and dental extractions are all indications for investigation. Bleeding may also occur in the presence of disorders such as systemic lupus erythematosus, liver disease, extrahepatic portal hypertension, gross splenomegaly, giant haemangiomas, reticuloendothelial malignancies and leukaemia.
Drug ingestion
Drugs may produce abnormal bleeding through:
• depression of clotting factors: anticoagulants, liver toxins
• bone marrow depression: chloramphenicol, cytotoxic agents, radiation
• antigen–antibody reactions with platelet membranes: quinine group of drugs
• direct inhibition of enzymes in platelets: aspirin effects on platelet cyclo-oxygenase.
Physical examination
The following should be noted on physical examination.
The type of skin bleeding
Petechiae alone strongly suggest a platelet or vessel problem, whereas ecchymoses alone suggest a factor deficiency. Combined petechiae and ecchymoses suggest a severe disorder, often of platelet origin.
The site of the bleeding
Confirmation of history, defining the number of all different bleeding sites, and assessment of severity of bleed and functional implications are all important aspects for both diagnosis and management.
Splenomegaly
Hypersplenism occurs when a large spleen removes platelets from the circulation, leading to bleeding. The problem is the underlying cause of the splenomegaly. Hepatomegaly, splenomegaly, lymphadenopathy and/or anaemia, in association with bleeding, strongly suggest leukaemia.
Investigation of bleeding in childhood
The tests in Table 16.2.2 are the most important.
Other tests
Measurement of von Willebrand factor level (antigen), activity (ristocetin co-factor and/or collagen binding assay) and factor VIII level are required to diagnose von Willebrand disorder. The bleeding time has lost favour because of its scarring potential but is characteristically prolonged in thrombocytopenia (normal 2–7 min), von Willebrand disorder and platelet function disorders, and is normal in other coagulation disorders.
Bleeding due to platelet disorders
Bleeding disorders resulting from platelet abnormalities are usually due to thrombocytopenia but may be due to qualitative platelet defects. The various types of inherited and acquired thrombocytopenia are listed in Table 16.2.3.
Table 16.2.3 Inherited and acquired thrombocytopenias
| Disorder | Key Information | |
|---|---|---|
| Acquired | ||
| Neonatal | Immune thrombocytopenia | Neonatal alloimmune or maternal autoimmune |
| Intrauterine infection | TORCH | |
| Pre-eclampsia | ||
| Birth asphyxia | ||
| Giant haemangioma | ‘Kasabach–Merritt syndrome’ features platelet consumption | |
| Any age | Immune thrombocytopenia (ITP) | The most common acquired thrombocytopenia |
| Inherited | ||
| With platelet dysfunction | Examples include Bernard–Soulier syndrome and Wiskott–Aldrich syndrome | Rare |
| Without platelet dysfunction | Examples include Fanconi anaemia and Alport syndrome | Rare |
| Mediterranean macrothrombocytopenia | Large platelets, autosomal dominant |
TORCH, toxoplasmosis, other (e.g. HIV and parvovirus B19), rubella, cytomegalovirus, herpes simplex.
Immune thrombocytopenic purpura
Immune thrombocytopenic purpura is the most common acquired bleeding disorder in children. It may be acute or chronic (defined as lasting longer than 12 months), episodic or continuous. Common to all clinical variations is the marked reduction in platelet life span due to immune-mediated splenic sequestration.
Features of typical acute immune thrombocytopenic purpura:
• 80–90% of paediatric immune thrombocytopenic purpura cases
• preceding viral illness is common
• otherwise normal examination – no lymphadenopathy or hepatosplenomegaly
• platelet count usually < 20 × 109/L
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