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What is the Lovibond angle?

Published in Medical Sign 1 min read

The Lovibond angle, also known as the "profile sign," is the angle formed by the nail as it exits the proximal nailfold. It was introduced in 1938 as a diagnostic criterion for finger clubbing.

Understanding the Lovibond Angle

Finger clubbing is a physical sign characterized by bulbous enlargement of the distal phalanges (bones of the fingers and toes). The Lovibond angle provides a way to quantify this characteristic.

  • Normal Angle: In healthy individuals, the Lovibond angle is typically 160 degrees or less.
  • Clubbing Angle: In individuals with finger clubbing, this angle is often greater than 180 degrees. The nail bed also becomes visibly more convex.

Importance in Diagnosis

Assessing the Lovibond angle is a simple, non-invasive method to screen for conditions associated with finger clubbing, such as:

  • Lung diseases (e.g., lung cancer, cystic fibrosis, bronchiectasis)
  • Heart conditions (e.g., cyanotic heart disease)
  • Gastrointestinal disorders (e.g., inflammatory bowel disease, cirrhosis)

While the Lovibond angle is a useful clinical sign, it should be interpreted in conjunction with other clinical findings and diagnostic tests to reach an accurate diagnosis.