What causes frequent bruising?

Causes of Frequent Bruising

Frequent bruising can be caused by bleeding disorders, medical conditions, medications, or normal physiological factors, and requires systematic evaluation to determine the underlying cause.

Medical Causes of Easy Bruising

Bleeding Disorders

• Von Willebrand disease (VWD) is a common inherited bleeding disorder that can cause easy bruising and may not be detected by standard coagulation tests (PT/aPTT) 1
• Mild hemophilia (factor VIII or IX deficiency) can cause significant bruising and bleeding despite normal aPTT results 1
• Immune thrombocytopenia (ITP) is a transient, often self-resolving bleeding disorder that should be screened for with a platelet count 1
• Platelet function disorders can present with bruising and mucocutaneous bleeding 1

Other Medical Conditions

• Ehlers-Danlos syndrome can cause easy bruising due to connective tissue abnormalities 1
• Scurvy (vitamin C deficiency) can lead to increased bruising 1
• Cancer and other infiltrative disorders may present with bruising 1
• Vitamin K deficiency can cause bleeding manifestations including bruising, particularly in infants 1

Medication and Supplement Effects

• Anticoagulant and antiplatelet medications significantly increase bruising tendency 1
• Certain medications can affect platelet function and coagulation test results 1
• Alternative therapies and supplements may increase bleeding/bruising risk 1

Diagnostic Approach

Initial Evaluation

• Assess for concerning symptoms that suggest a bleeding disorder:
  • History of excessive bleeding after surgery, dental procedures, or circumcision 1
  • Epistaxis (nosebleeds) that are frequent or difficult to stop 1
  • Family history of bleeding disorders 1
  • Bleeding from umbilical stump in infants 1

Laboratory Testing

• Initial screening panel for bruising should include:

  • Complete blood count with platelet count (to detect thrombocytopenia) 1
  • Prothrombin time (PT) and activated partial thromboplastin time (aPTT) 1
  • Additional testing for von Willebrand disease may be needed as PT/aPTT may be normal 1

• For more extensive evaluation, consider:

  • Fibrinogen concentration and thrombin time (for rare fibrinogen defects) 1
  • Factor XIII testing (not detected by routine screening) 1
  • Platelet function testing (requires specialist interpretation) 1

Special Considerations

Normal vs. Pathological Bruising

• Some individuals bruise more easily due to:
  • Fair skin making bruises more visible 1
  • Thin skin, particularly in elderly individuals 2
  • Normal variations in capillary fragility 2

When to Suspect More Serious Causes

• Bruising in unusual locations (not over bony prominences) 3
• Bruising without remembered trauma 2
• Large or numerous bruises disproportionate to reported trauma 4
• Bruising accompanied by other bleeding symptoms (gum bleeding, heavy menstrual periods) 4
• Bruising that takes unusually long to resolve 2

Pitfalls to Avoid

• Not all bleeding disorders cause abnormalities in standard screening tests (PT/aPTT) 1
• Mild factor deficiencies may still result in significant bleeding despite normal test results 1
• Local bruising and bleeding from injections do not necessarily indicate a bleeding disorder 1
• Recent studies show overlap in bruising characteristics between children with hematologic disorders and other causes of bruising 5

Management Approach

• For mild, isolated bruising without other concerning symptoms, reassurance may be appropriate 2
• For recurrent, extensive, or unexplained bruising, referral to a hematologist should be considered 2
• When bleeding disorders are suspected, consultation with a pediatric hematologist is recommended for proper interpretation of specialized tests 1
• For bruising associated with anticoagulant therapy, applying pressure to injection sites for 5-10 seconds can help prevent bruising 1