Mild bleeding disorders in adults.

Patients in primary care frequently report mild bleeding that may warrant further investigation

About 11% of patients in primary care reported bleeding symptoms in a 2010 Canadian study.1 Mild bleeding disorders should be considered in patients with disproportionate bleeding (i.e., excessive postsurgical bleeding from multiple sites or bleeding that requires blood or iron transfusion).2 Mild bleeding disorders can be inherited or acquired; common diagnoses include mild von Willebrand disease, platelet dysfunction and mild–moderate factor deficiencies.2 Unlike severe inherited bleeding disorders that are often diagnosed in early life, mild inherited bleeding disorders can present in adulthood.

Identifying someone with mild bleeding requires a systematic approach

First steps include a detailed medical history emphasizing bleeding and family history, a physical examination to rule out secondary conditions (e.g., Cushing syndrome or Ehlers–Danlos syndrome) (Appendix 1, available at www.cmaj.ca/lookup/doi/10.1503/cmaj.201182/tab-related-content) and laboratory-screening tests listed in point 4.2 Recognition of an inheritance pattern could help narrow the differential diagnosis (e.g., X-linked recessive pattern in hemophilia A).

An assessment tool may be helpful in differentiating clinically relevant from inconsequential bleeding

The ISTH-SSC Bleeding Assessment Tool (ISTH/SSC-BAT) may be used to differentiate the 2 types of bleeding. The tool comprises 14 distinct bleeding manifestations and takes about 20 minutes for the patient to complete (www.isth.org/page/reference_tools).3 A positive score of 4 or more in males and 6 or more in females justifies referral to a specialist. However, the tool may fail to identify people with acquired bleeding disorders and is less sensitive in younger patients who have never undergone surgery.

Initial laboratory screening tests inform decisions about further testing

Initial laboratory screening tests should include complete blood cell count, prothrombin time/international normalized ratio, activated partial thromboplastin time, fibrinogen level and a blood smear. If the ISTH/SSC-BAT score is negative and results for the laboratory screening tests are unremarkable, ongoing clinical observation is sufficient without further testing.4 Conversely, a positive ISTH/SSC-BAT score with normal results for laboratory tests will require referral for further evaluation.

An acquired bleeding disorder may develop later in life

Mildly disordered bleeding that arises later in life may indicate the presence of an acquired bleeding disorder, and the patient should be evaluated for underlying systemic disease. The diverse causes for an acquired bleeding disorder are listed in Appendix 1. A structured approach is necessary to ensure pathologies, such as malignant disease associated with acquired bleeding disorders, are ruled out (e.g., acquired hemophilia A, immunoglobulin M hyperviscosity syndrome and light-chain amyloidosis).5,6