Finger Clubbing: A quantitative survey by analysis of the shadowgraph

Finger-clubbing has been measured from the magnified silhouette of the right index finger (shadowgram) in 125 subjects, comprising children and young adults. The profile and hyponychial angles were both found to be good discriminators of clubbing and to be independent of age and sex. The normal profile angle was 168.3 degrees +/- 3.6 and the mean normal hyponychial angle was 180.1 degrees +/- 4.2. Patients with cystic fibrosis and cyanotic congenital heart-disease were found to have grossly elevated values of these angles. Some asthmatics were found to have a moderate degree of clubbing with significantly elevated values of these angles. The shadowgram proved a convenient objective method for recording the degree and progress of fingerclubbing in clinical practice.