Clubbing

### Make the Diagnosis: Clubbing

#### Prevalence of Clubbing

The probability of clubbing depends on the underlying illness. Among a convenience sample of hospitalized, general medical inpatients, the frequency of a quantitatively measured hyponychial angle greater than 192 degrees was 8.9%.1

#### Population for Whom Clubbing Should Be Considered

Clubbing can occur in a variety of illnesses. It should be considered among patients with cystic fibrosis or bronchiectasis as a marker for chronic hypoxemia. In patients with clubbing that is not congenital, it would be reasonable to obtain a chest radiograph to look for pulmonary conditions associated with clubbing.

#### Reference Standard Tests

The pragmatic standard is examination by an experienced clinician, although laborious quantitative measures can be done as part of a research study.

### Original Article: Does This Patient Have Clubbing?

#### Clinical Scenarios

##### Case 1

A respiratory therapist asks you to see her asymptomatic 76-year-old mother in consultation because she is concerned that her mother has clubbing. The patient has increased curvature of the nails, and you wonder whether other physical examination techniques can help you decide whether clubbing is present.

##### Case 2

While performing a routine physical examination on a 65-year-old female smoker with chronic obstructive pulmonary disease (COPD), you detect changes in the fingers suggestive of clubbing. You recall an association between clubbing and certain types of pulmonary disease, and you wonder whether any further diagnostic evaluation of this patient is warranted.

#### Why Is the Clinical Examination Important?

Clubbing is one of those phenomena with which we are all so familiar that we appear to know more about it than we really do.1

—Samuel West, 1897

The association of clubbing with a host of infectious, neoplastic, inflammatory, and vascular diseases has captured the imagination of clinicians since Hippocrates first described clubbing in a patient with empyema in the fifth century bc.2 Although clubbing can be a benign hereditary condition, the diagnostic implications in an adult are such that its detection should prompt consideration of the underlying etiology (Table 14-1).3, 4 In the pediatric population, clubbing usually represents the progression of established diseases, such as cystic fibrosis or uncorrected cyanotic congenital heart disease.

Table 14-1Conditions Associated With Acquired Clubbing

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

## Subscription Options

### JAMAevidence Full Site: One-Year Subscription

Connect to the full suite of JAMAevidence content and resources including interactive self-assessment, videos, and more.