In pulmonary embolism, unilateral leg findings may be present; which sign is classically described?

In pulmonary embolism, unilateral leg findings may be present; which sign is classically described?

• A. Homan's sign
• B. Trousseau sign
• C. Kernig sign
• D. Murphy sign

Answer: (A)

Unilateral leg findings in a patient who may have a pulmonary embolism point toward a deep venous thrombosis in the leg that could have embolized to the lungs. The sign classically described is pain in the calf or tenderness on forced dorsiflexion of the foot—a gesture historically called Homan’s sign. The idea is that stretching the calf over an inflamed venous thrombus provokes pain, suggesting a DVT that could be the source of a PE. However, this sign is not a reliable test on its own. It has low sensitivity and specificity and can be absent in many patients with DVT, while other conditions can cause similar pain. Modern assessment relies on duplex ultrasound of the leg and D-dimer testing, with imaging of the chest as indicated for suspected PE. The other signs are not characteristic here: Trousseau sign historically refers to migratory thrombophlebitis associated with cancer (or, in a different context, to a test for latent tetany), and Kernig and Murphy signs point to meningitis/subarachnoid irritation and gallbladder inflammation, respectively.

Unilateral leg findings in a patient who may have a pulmonary embolism point toward a deep venous thrombosis in the leg that could have embolized to the lungs. The sign classically described is pain in the calf or tenderness on forced dorsiflexion of the foot—a gesture historically called Homan’s sign. The idea is that stretching the calf over an inflamed venous thrombus provokes pain, suggesting a DVT that could be the source of a PE.

However, this sign is not a reliable test on its own. It has low sensitivity and specificity and can be absent in many patients with DVT, while other conditions can cause similar pain. Modern assessment relies on duplex ultrasound of the leg and D-dimer testing, with imaging of the chest as indicated for suspected PE.

The other signs are not characteristic here: Trousseau sign historically refers to migratory thrombophlebitis associated with cancer (or, in a different context, to a test for latent tetany), and Kernig and Murphy signs point to meningitis/subarachnoid irritation and gallbladder inflammation, respectively.