Q&A: Diseases Presenting With Finger Clubbing

The human nail shields the distal digit from harm, assists in the picking up of small objects, improves fine touch, and enhances the aesthetic appearance of the hand. Aesthetically displeasing nails and nail-associated symptoms, such as pain or throbbing, are common factors that contribute to a patient's decision to seek medical attention. The nail may also be disfigured in finger clubbing, a sign seen in a number of medical conditions.

This article is for Medical Students & Professionals

This is a Question & Answer revision article designed for medical students and professionals preparing for the PLAB, MRCP or USMLE examinations. They are based on actual questions from these examinations. You may find the Finger Clubbing article more useful, or one of our many articles on Diseases & Conditions, Medical Syndromes, Health & Wellness or Home Remedies.

In this article:
What is finger clubbing?
MCQ: clinical scenario
MCQ: answer
MCQ: explanation

What is finger clubbing?

Digital clubbing is characterized by increased distal fingertip mass and increased longitudinal and transverse nail plate curvature. The Lovibond angle, the angle between the nail plate and the proximal nail fold when viewed from the side, is >180° in clubbed nails and 160° in normal nails. Clubbed fingers show the Schamroth sign, the obliteration of the diamond-shaped window normally visible when the dorsal surfaces of the terminal phalanges of corresponding fingers from opposite hands are placed together.

MCQ: clinical scenario

A 54 year old man presents with a symmetrical distal arthopathy. On examination he has finger clubbing and a symmetrical arthropathy. Radiography demonstrates visible periosteal new bone formation over the diaphyses of his metacarpals and phalanges.

These features are a recognised complication of:

a) Juvenile rheumatoid arthritis
b) Scleroderma
c) Epidermolysis bullosa
d) Bronchial carcinoma
e) Infectious mononucleosis

MCQ: answer

The correct answer is D

MCQ: explanation

Digital clubbing is the most common manifestation of hypertrophic osteoarthropathy (HPOA). Hypertrophic pulmonary osteoarthropathy is often diagnosed radiologically when a patient presents with a symmetrical distal arthopathy. It is characterised by finger clubbing and a vaguely symmetrical arthropathy, with visible periosteal new bone formation over the diaphyses, but usually not extending to the bone end. There may be hyperaemia. The condition is thought to be a form of autonomic neuropathy, although the exact mechanism is not fully understood. The more pronounced that a uniform periosteal reaction appears, then the greater likelihood of the patient's having survived long enough to generate it.

In adults, intrathoracic sepsis and carcinoma of the bronchus are the most frequent underlying conditions. Congenital heart disease has an association with HPOA. This and bowel disorders such as Crohn's disease, are more probable in the young as causes of peripheral periosteal reactions.

Reference(s)
1). UpToDate: Overview of nail disorders. Available online: https://www.uptodate.com/contents/overview-of-nail-disorders