Clubbed fingers, also known as digital clubbing or Hippocratic fingers, is a clinical sign characterized by bulbous enlargement of the distal phalanges of the fingers and toes. It is often associated with various underlying medical conditions.

Characteristics

• Increased curvature of the nail bed
• Widening and thickening of the terminal phalanx
• Increased angle between the nail plate and the proximal nail fold (Lovibond’s angle > 180°)
• Sponginess of the nail bed
• Loss of the normal angle between the nail and the nail bed (Schamroth’s sign)

Pathophysiology

The exact mechanism is not fully understood, but theories include:

• Increased blood flow to the distal digits
• Hypoxia-induced vascular endothelial growth factor (VEGF) production
• Platelet-derived growth factor release from megakaryocytes

Associated Conditions

Pulmonary diseases:

• Lung cancer
• Chronic lung infections (e.g., bronchiectasis, lung abscess)
• Cystic fibrosis
• Interstitial lung diseases

Cardiovascular diseases:

• Infective endocarditis
• Cyanotic congenital heart diseases

Gastrointestinal diseases:

• Inflammatory bowel disease
• Liver cirrhosis

Others:

• Thyroid acropachy
• HIV infection
• Some hereditary conditions

Diagnosis

• Clinical examination
• Chest X-ray or CT scan to evaluate for underlying lung pathology
• Echocardiogram if cardiac cause is suspected
• Additional tests based on suspected underlying condition

Clinical Significance

• Important physical finding that can indicate serious underlying pathology
• Early recognition can lead to timely diagnosis of associated conditions