Clubbing

Background

• Clinical exam finding of fingers and toes characterized in an increase in the mass of the distal fingertip and increase in the longitudinal and transverse nail plate curvature

Physical Examination

• Assess the thickness of the distal fingertip
• Lovibond angle is over 180 degrees, compared to 160 degrees in normal nails
• Schamroth sign

Etiologies

• Acquired, usually starting with thumb and index fingers
  • Lung cancer, IPF, lung abscess, pulmonary tuberculosis, pulmonary lymphoma
  • Heart failure, endocarditis, congenital heart disease
  • Inflammatory bowel disease, liver cirrhosis, gastrointestinal cancer
• Acquired unilateral or single-digit clubbing
  • Nearby vascular lesions
  • Pancoast tumour
  • Lymphadenitis
  • Erythromelalgia
  • Trauma
• Isolated congenital digital clubbing, a form of primary hypertrophic osteoarthropathy