Clubbing

Clubbing

Clubbing refers to a physical change in the appearance of the fingers and toes, where the ends become enlarged and the nails curve around the fingertips. This condition is often associated with various diseases, particularly those affecting the heart and lungs.

History

The phenomenon of clubbing was first described by Hippocrates in ancient Greece, and it is sometimes referred to as "Hippocratic fingers." It has been recognized as a clinical sign of disease for centuries.

Pathophysiology

Clubbing occurs due to changes in the soft tissue beneath the nail beds. The exact mechanism is not fully understood, but it is believed to involve increased blood flow to the distal phalanges and changes in connective tissue. Vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF) have been implicated in the process.

Causes

Clubbing can be a sign of several underlying conditions, including:

• Pulmonary diseases: Such as lung cancer, cystic fibrosis, and interstitial lung disease.
• Cardiovascular diseases: Including cyanotic heart disease and infective endocarditis.
• Gastrointestinal diseases: Such as inflammatory bowel disease and cirrhosis.
• Other conditions: Such as thyroid acropachy and familial clubbing.

Diagnosis

Diagnosis of clubbing is primarily clinical. The following features are typically assessed:

• Schamroth's sign: Loss of the normal diamond-shaped window when the dorsal surfaces of the distal phalanges of corresponding fingers are opposed.
• Lovibond's angle: An angle greater than 180 degrees between the nail and the nail bed.
• Increased nail bed fluctuation: Softening of the nail bed.

Differential Diagnosis

Clubbing should be differentiated from other conditions that affect the nails, such as:

• Onycholysis
• Koilonychia
• Psoriatic nail disease

Management

Management of clubbing involves addressing the underlying cause. There is no specific treatment for clubbing itself. If the underlying condition is treated successfully, clubbing may regress.

Prognosis

The prognosis of clubbing depends on the underlying disease. In some cases, such as lung cancer, it may indicate advanced disease and a poorer prognosis.

See Also

• Nail diseases
• Pulmonary manifestations of systemic disease

External Links

• Article on clubbing in the medical literature