Clubbing refers to enlargement and rounding of the fingertips. Two methods are used to diagnose clubbing: the phalangeal depth ratio and digital index. A phalangeal depth ratio greater than 1 or a digital index over 10.2 indicates clubbing. The main respiratory causes of clubbing include lung cancers, mesothelioma, lung infections like bronchiectasis and cystic fibrosis, and interstitial lung diseases. Other causes include syphilis, syringomyelia, acromegaly, and thyrotoxicosis. Reverse clubbing, where the upper limbs show clubbing and lower limbs do not, can indicate transposition of the great arteries.

1. CLUBBING
Dr.G.VENKATARAMANA
MBBS DNB FAMILYMEDICINE

4. • Phalangeal Depth Ratio
• Ratio of distal phalangeal depth (DPD) with interphalangeal depth (IPD)
• <1 is normal, >1 is suggestive of clubbing
• Digital Index
• Sum of phalangeal depth ratios of 10 fingers
• A digital index of 10.2 or higher is indicative of clubbing. Although, a
phalangeal depth ratio of 1.0 or greater in any finger is suggestive of
clubbing, digital index is more specific for clubbing

18. • What are the respiratory causes of clubbing?
• A. Bronchogenic carcinoma (rare in adenocarcinoma)
• B. Metastatic lung cancer
• C. Pleural mesothelioma
• D. Suppurative lung disease
• 1. Bronchiectasis
• 2. Cystic fibrosis
• 3. Lung abscess
• 4. Empyema
• E. Interstitial lung disease
• F. Longstanding pulmonary tuberculosis
• G. Chronic bronchitis
• H. Neurogenic diaphragmatic tumour
• I. Pulmonary AV malformation
• J. Sarcoidosis

21. • What are the other causes of clubbing?
 Syphilis
 Syringomyelia
 Acromegaly
 Thyrotoxicosis
 Congenital/Familial
 Occupational/Traumatic
 Pachydermoperiostitis

25. • Reverse differential clubbing:
• Upper limb (clubbing)
• Lower limb (N)
• PDA + transposition of the
great arteries (TGA) + reversal
of shunt
• Pseudoclubbing • Leprosy
• Leukemic infiltration
• Hyperparathyroidism
• Thyroid acropachy
• Sclerodactyly
• Exposure to vinyl chloride
• Subungual tumors or cysts
• Unidigital clubbing • Tophaceous gout
• Local injury
• Sarcoidosis