What is the laboratory workup for easy bruising, also known as ecchymosis (easy bruising) or purpura (bleeding under the skin)?

From the Guidelines

A workup for easy bruising should include a complete blood count (CBC), prothrombin time (PT), activated partial thromboplastin time (aPTT), von Willebrand factor antigen and activity, and factor VIII levels, as recommended by the most recent guidelines 1. When evaluating a patient with easy bruising, it is essential to consider a comprehensive approach that includes laboratory tests and a thorough medical history.

• The initial laboratory evaluation should include a CBC to assess platelet count and morphology, as well as coagulation studies such as PT and aPTT 1.
• Additional tests should include von Willebrand factor antigen and activity, factor VIII levels, and a comprehensive metabolic panel to evaluate liver function 1.
• A bleeding score, such as the ISTH BAT score, may also be useful in assessing the severity of bleeding symptoms 1.
• If medication-induced bruising is suspected, a medication review is essential, particularly focusing on anticoagulants, antiplatelets, NSAIDs, and certain antibiotics.
• For patients with significant or unexplained bruising, specialized tests like platelet function assays or fibrinogen levels may be warranted 1.
• Physical examination should document the size, location, and appearance of bruises, and a thorough history should include onset, family history of bleeding disorders, and associated symptoms like nosebleeds or heavy menstrual periods. The most recent study 1 provides guidance on the diagnosis and management of bleeding disorders, including easy bruising, and recommends a comprehensive approach that includes laboratory tests, medical history, and physical examination.

From the Research

Easy Bruising Lab Workup

The lab workup for easy bruising typically involves a series of tests to determine the underlying cause of the condition.

• A complete blood cell count, platelet count, and evaluation of a peripheral blood sample are often included in the initial workup 2, 3, 4, 5.
• Prothrombin time and activated partial thromboplastin time are also commonly used to assess coagulation disorders 2, 3, 4, 5, 6.
• A normal prothrombin time with a prolonged activated partial thromboplastin time may indicate a disorder of the intrinsic coagulation pathway, while a prolonged prothrombin time with a normal activated partial thromboplastin time may indicate a disorder of the extrinsic coagulation pathway 3, 4.
• If von Willebrand disease is suspected, more specific laboratory tests such as assays of factor VIII, von Willebrand factor antigen, and von Willebrand factor activity may be necessary 2.
• A bleeding assessment tool and a comprehensive history, physical examination, and patient-provided photographs can also help identify causes of abnormal bleeding and bruising 3, 4.

Laboratory Tests

The following laboratory tests may be included in the workup for easy bruising:

• Complete blood count (CBC) 2, 3, 4, 5
• Platelet count 2, 3, 4, 5
• Prothrombin time (PT) 2, 3, 4, 5, 6
• Activated partial thromboplastin time (aPTT) 2, 3, 4, 5, 6
• Fibrinogen 3
• Factor VIII assay 2
• Von Willebrand factor antigen assay 2
• Von Willebrand factor activity assay 2
• Template bleeding time 2

Specialized Tests

In some cases, more specialized tests may be necessary to diagnose the underlying cause of easy bruising, such as:

• Platelet Function Analyzer-100 5
• Mixing studies 4, 5
• Inhibitor assays 5
• Multimeric analysis of von Willebrand factor 2