Clubbing

Key Points
Deformity of the fingers and fingernails
Some cases associated with various conditions, over half are spontaneous
Consists of convex, softened nails and nailbeds and enlarged, thickened fingers

Clubbing is a deformity which most often affects the fingers and fingernails, but may also appear in the toes and toenails. Clubbing consists of a thickening of the flesh under the nail, causing the angle of the nail to change. Digits become enlarged and thickened, and nails and nail beds become softened and develop a pronounced convex shape.

It is unknown what causes Clubbing, and over half of cases (60%) are spontaneous, with no underlying condition causing its appearance. In cases where Clubbing is associated with another condition, lung disease of varying types are the most common, including lung cancer, Tuberculosis and Mesothelioma. Clubbing has also been shown in persons with heart disease, gastrointestinal disorders, hyperthyroidism, and vascular anomalies in the affected limb. Additionally, there is a form of Clubbing, familial Clubbing, which appears to be hereditary. Clubbing is also a major symptom of Hypertrophic Osteoarthropathy, a hereditary disorder of the joints and bones.

Differential Diagnosis (Other conditions with similar appearance)

Pachydermoperiostosis
Hypertrophic osteoarthropathy
Dermatologic manifestations of cardiac, gastrointestinal, hematologic, and pulmonary diseases

Diagnosis
Key Points
Diagnosis based on appearance of the affected digits
Schamroth's test will be performed to confirm diagnosis
Clinical, laboratory and radiological testing may be performed to rule out associated conditions

Clubbing is diagnosed based on the appearance of the affected digits. At this point, health care professionals will perform Schamroth's test, which examines the area and shape of the nail bed, to confirm the diagnosis. Clinical, laboratory and radiological testing may be performed to rule out associated conditions after initial diagnosis is confirmed.

Treatment
There is no specific treatment for Clubbing
Goal of treatment is to treat the underlying condition, if appropriate
*If associated with an underlying condition, treatment of that condition may decrease or even reverse the symptoms

There is not a specific treatment for Clubbing, but if it is associated with an underlying condition, treatment of that condition may decrease Clubbing, and if begun early enough, even reverse it completely. However, once tissue damage is substantial, reversal becomes very unlikely.