What is the meaning of the Frank sign?

Frank's Sign: A Dermatological Marker for Atherosclerotic Disease

Frank's sign (diagonal earlobe crease or DELC) is a significant physical finding that serves as a dermatological marker for atherosclerosis and is strongly associated with coronary artery disease, cerebrovascular disease, and peripheral vascular disease. 1, 2

Definition and Appearance

• Frank's sign is a diagonal earlobe crease that extends backwards from the tragus at a 45-degree angle across the lobule to the auricular edge of the ear 1
• The sign is named after Dr. Sanders T. Frank, who first described this finding in 20 patients with coronary artery disease in 1973 in The New England Journal of Medicine 1
• The appearance can vary in depth and may be present unilaterally or bilaterally 3

Pathophysiological Significance

• Histopathological examination of DELC-positive earlobes reveals myoelastofibrosis in the arterial vessels at the base of the earlobe, indicating a direct relationship to atherosclerosis rather than a coincidental finding 1
• The presence of Frank's sign correlates significantly with the severity of coronary artery disease (rs = 0.474, p < 0.001) and with the severity of general atherosclerosis (rs = 0.606, p < 0.001) 3
• Frank's sign represents an independent risk factor for atherosclerotic disease, similar to uncontrollable risk factors like age or gender 1

Clinical Associations

• Coronary Artery Disease: In patients with lethal cardiac events, 78% showed high-grade DELC, demonstrating its strong association with coronary pathology 3
• Cerebrovascular Disease: Frank's sign has been found in 78.8% of patients hospitalized with acute stroke, with a higher prevalence in those with cerebrovascular accidents (88.6%) compared to those with transient ischemic attacks (73.2%) 2
• The association remains significant even after accounting for traditional cardiovascular risk factors 2, 3

Clinical Implications

• Earlobe inspection should be considered an integral part of the physical examination in clinical practice 1, 4
• When Frank's sign is identified, further cardiovascular and cerebrovascular evaluation is warranted, including:
  • Color Doppler ultrasound examination of the neck arteries 1
  • Cardiological examination 1
  • Assessment of other cardiovascular risk factors 2
• Frank's sign can be particularly valuable for early detection of atherosclerotic disease in younger patients, where its prognostic value may be more significant 3, 5

Practical Application

• The sign can be easily assessed during routine physical examination without requiring specialized equipment 5
• It serves as a simple, non-invasive screening tool to identify patients who may benefit from more comprehensive cardiovascular risk assessment 4
• In patients with pre-existing cardiac disease, the presence of Frank's sign should heighten vigilance for potential acute coronary events 5

Limitations

• The influence of age is significant, as both DELC and coronary artery disease increase in prevalence with advancing age 3
• The prognostic value appears to be more limited in older populations and more valuable in younger patients 3

Frank's sign represents an important physical finding that clinicians should routinely assess, as it provides valuable information about a patient's atherosclerotic burden and risk for cardiovascular and cerebrovascular events.