++
My pa is one mask of brooses both blue and green.
CHARLES DICKENS (1812–70), NICHOLAS NICKLEBY
++
Many patients present with the complaint that they bruise easily but only a minority turn out to have an underlying blood disorder. Purpura is bleeding into the skin or mucous membranes, appearing as multiple small haemorrhages that do not blanch on pressure. Smaller purpuric lesions that are 2 mm or less in diameter (pinhead size) are termed petechiae, while larger purpuric lesions are called ecchymoses (see FIG. 39.1).
++
++
Bruises are large areas of bleeding that are a result of subcutaneous bleeding. If bruising is abnormal and out of proportion to the offending trauma, then a disturbance of coagulation is suggested (see FIG. 39.2). The three spontaneous pathways that arrest bleeding following injury are vasoconstriction, platelet plugging of gaps and the coagulation cascade (intrinsic and extrinsic pathways).
++
++
DIFFERENTIAL DIAGNOSIS
++
‘Palpable purpura’ due to an underlying systemic vasculitis is an important differential problem. The petechiae are raised so finger palpation is important. The cause is an underlying vasculitis affecting small vessels (e.g. polyarteritis nodosa).
++
The decision to investigate is difficult because decisions have to be made about which patients warrant investigation and whether the haemostatic defect is due to local or systemic pathology.1 The ability to identify a bleeding disorder is important because of implications for surgery, pregnancy, medication and genetic counselling.
++
Key facts and checkpoints
Purpura = petechiae + ecchymoses.
Abnormal bleeding is basically the result of disorders of (1) the platelet, (2) the coagulation mechanism or (3) the blood vessel.
There is no substitute for a good history in the assessment of patients with bleeding disorders.
An assessment of personal and family histories is the first step in the identification of a bleeding disorder.
When a patient complains of ‘bruising easily’ it is important to exclude thrombocytopenia due to bone marrow disease and clotting factor deficiencies such as haemophilia.
The commonest cause of an acquired bleeding disorder is drug therapy (e.g. aspirin, NSAIDs, cytotoxics and oral anticoagulants).
In general, bleeding secondary to platelet defects is spontaneous, associated with a petechial rash and occurs immediately after trauma or a cut wound.1 The bleeding is usually mucosal (e.g. bleeding from gingiva, menorrhagia, epistaxis and petechiae).
Laboratory assessment should be guided by the clinical impression.
Bleeding caused by coagulation factor deficiency is usually traumatic and delayed (e.g. haemorrhage occurring 24 hours ...