What is the appropriate evaluation and management for a 36-year-old female with bruising on her leg?

Evaluation and Management of Leg Bruising in a 36-Year-Old Female

In a 36-year-old woman with leg bruising, obtain a detailed history of trauma, medication use (especially anticoagulants, antiplatelets, NSAIDs, or corticosteroids), and bleeding symptoms, then perform initial laboratory testing with complete blood count, PT/INR, aPTT, and fibrinogen if the bruising is disproportionate to reported trauma, occurs in multiple unusual locations, or if there is a personal or family history of bleeding disorders. 1, 2, 3

Initial Clinical Assessment

History Taking Priority Points

• Document the exact mechanism of injury verbatim, including whether there was direct trauma from a blow or fall, as this determines whether further workup is needed 1, 4
• Review all medications systematically, as anticoagulants (warfarin), antiplatelets, NSAIDs, and corticosteroids commonly cause increased bruising in adults 2, 5
• Screen for bleeding disorder symptoms including excessive bleeding after surgery or dental procedures, heavy menstrual bleeding, frequent nosebleeds, or easy bruising throughout life 6, 3
• Obtain family history of bleeding disorders, as hereditary conditions like von Willebrand disease affect 1 in 1000 people and may present with mild bruising 2, 3

Physical Examination Focus

• Examine for mucocutaneous bleeding (petechiae, gum bleeding, nosebleeds), which suggests platelet dysfunction rather than coagulopathy 3
• Look for hemarthroses or deep hematomas, which indicate coagulation factor deficiencies 3
• Document bruise location photographically, as leg bruising on the shin or knee with consistent trauma history is typically benign, while bruising on unusual locations warrants investigation 1, 7

Laboratory Evaluation Algorithm

When to Order Initial Testing

Order laboratory workup if any of the following are present:

• Bruising disproportionate to the reported trauma 1, 2
• Multiple bruises in unusual locations (not on bony prominences) 1, 3
• Personal history of excessive bleeding with minor trauma, surgery, or dental procedures 6, 3
• Family history of bleeding disorders 6, 3
• Current use of anticoagulants with unexplained bruising 5

First-Line Laboratory Panel

The essential initial tests are:

• Complete blood count with platelet count and peripheral smear to identify thrombocytopenia, abnormal platelet morphology, or hematologic malignancies 2, 3, 7
• Prothrombin Time (PT/INR) to evaluate the extrinsic coagulation pathway and detect vitamin K deficiency, liver disease, or factor VII deficiency 2, 3, 7
• Activated Partial Thromboplastin Time (aPTT) to assess the intrinsic coagulation pathway and screen for hemophilia and other factor deficiencies 2, 3, 7
• Fibrinogen level because routine coagulation testing will miss fibrinogen disorders 2, 7

Critical Pitfall: Normal Screening Does Not Exclude All Bleeding Disorders

Normal PT/aPTT results do not rule out von Willebrand disease, Factor XIII deficiency, or platelet function disorders, which are common causes of easy bruising 2, 3, 7

Additional Testing When Initial Screening is Normal

If clinical suspicion remains high despite normal PT, aPTT, platelet count, and fibrinogen:

• Von Willebrand factor testing panel including VWF antigen, VWF ristocetin cofactor activity, and Factor VIII coagulant activity should be performed, as von Willebrand disease is the most common inherited bleeding disorder yet standard coagulation tests fail to detect it 2
• Liver function tests to assess hepatic synthetic function, as liver disease commonly causes coagulopathy 2, 3
• Renal function tests because uremia affects platelet function 2

Management Based on Findings

If Anticoagulant-Related (Warfarin)

• Excessive bruising with therapeutic INR warrants diagnostic investigation to unmask previously unsuspected lesions such as tumors or ulcers 5
• If INR is supratherapeutic without major bleeding, hold warfarin and consider oral vitamin K1 (5-10 mg) 5
• For severe hemorrhage, administer parenteral vitamin K1 (5-25 mg, rarely up to 50 mg) and consider fresh frozen plasma (200-500 mL) or commercial Factor IX complex in life-threatening situations 5

If Trauma-Related Without Bleeding Disorder

• Single bruises on the shin or knee with consistent accidental trauma history do not require further workup 1
• Deep muscle bruises from direct trauma require rest, activity restriction, ice application, compression, and protection from further injury 4

When to Refer to Hematology

Consultation with a hematologist is recommended when:

• Initial laboratory evaluation indicates a bleeding disorder 7
• Suspicion remains high despite normal laboratory workup 3, 7
• Specialized testing such as platelet function studies, Factor XIII assay, or VWF multimer analysis is needed 2

Key Clinical Pitfalls to Avoid

• Do not assume yellow bruising indicates an older bruise, as 16% of bruises can be predominantly yellow within the first 24 hours 8
• Do not dismiss bruising in patients on anticoagulation as "expected" without investigating for underlying pathology, as bleeding during anticoagulant therapy does not always correlate with PT/INR and may unmask serious lesions 5
• Do not stop evaluation at normal PT/aPTT if clinical suspicion is high, as these tests miss the most common inherited bleeding disorder (von Willebrand disease) 2, 3