Respirology/ ICU

How to Assess for Nail Clubbing (JAMA)

The JAMA Rational Clinical Examination recommends two clinical signs:

  1. The Lovibond angle (angle between proximal nail bed and nail plate) CLUBBING: >180° (normal is 160° or less)
  2. Distal phalangeal finger depth (DPD) to Interphalangeal finger depth (IPD) ratio. CLUBBING: DPD > IPD (normal is IPD > DPD)

NOTE: The Schamroth’s sign (Obliteration of diamond-shaped window between the dorsum of terminal phalanges) is typically taught during bedside rounds but the precision and accuracy of this sign have not been formally tested.

REFERENCES

  1. Lampe RM, Kagan A. Detection of clubbing—Schamroth’s sign. Clin Pediatr (Phila). 1983;22(2):125.
  2. Myers KA, Farquhar DR. Does This Patient Have Clubbing?. JAMA. 2001;286(3):341-347. doi:10.1001/jama.286.3.341
  3. Validity and Reliability of the Schamroth Sign for the Diagnosis of Clubbing.  JAMA. 2010;304(2):159-161. doi:10.1001/jama.2010.935
Get Medical Pearls directly to your inbox every week!
Weekly posts with high yield medical knowledge, directly to your mailbox!
Dr. C Humphreys

Internal Medicine

Recent Posts

Mechanism of a Mixed Apnea

Mixed apneas are characterized by absent respiratory effort and airflow in the first section of…

12 months ago

How Does Hypothyroidism Cause Hypoventilation?

Although rare, the differential diagnosis of hypoventilation and hypercapnia respiratory failure includes hypothyroidism. It is…

12 months ago

Why is Pro-BNP/ BNP lower in Obesity?

B-type natriuretic peptide (BNP) is a hormone created in response to cardiac wall stretch due…

1 year ago

What is Peribronchovascular Distribution on CT imaging?

A common finding described on computed tomography (CT) imaging. A disease with a peribronchovascular distribution…

2 years ago

Trapped Lung vs. Lung Entrapment

Though often used synonymously; Trapped Lung and Lung Entrapment technically describe separate entities along the…

3 years ago

Cause of Pericardial Effusion in Pulmonary Hypertension: Pathogenesis

It is not clearly understood why patients with pulmonary hypertension (PH) develop pericardial effusions. However,…

3 years ago

This website uses cookies.