Which physical examination finding is a sensitive indicator of acute pericarditis, though not always present?

• A. Hallmark chest pain
• B. Pericardial friction rub
• C. Pitting edema
• D. Decreased breath sounds

Answer: (B)

In acute pericarditis, the inflamed pericardial surfaces rub against each other, producing a friction rub. This auscultated sound is a highly specific sign of pericardial inflammation and, when present, strongly supports the diagnosis. It’s typically a high-pitched, scratching or grating noise heard best with the patient leaning forward, usually at the left lower sternal border and during expiration. However, it isn’t always present—friction rubs can be intermittent or masked by a small effusion or rapid heart rate—so absence does not rule out pericarditis.

By comparison, chest pain is a symptom rather than a physical finding; edema reflects fluid overload or chronic heart conditions and is nonspecific; decreased breath sounds can point to other issues like effusion or lung pathology and isn’t specific for pericarditis.