ITE Board General Internal Medicine Practice Test

Empiric antibiotic therapy for pharyngitis is indicated when the clinical scoring system suggests a high likelihood of streptococcal infection, which is often assessed using the Centor criteria. A score of 4 indicates a high probability of Group A Streptococcus (GAS) infection, suggesting the need for antibiotic treatment to prevent complications like rheumatic fever or to alleviate severe symptoms.

The Centor criteria use factors such as fever, exudates on the tonsils, tender anterior cervical lymphadenopathy, and absence of cough to derive a score ranging from 0 to 4. At a score of 4, the likelihood of a positive throat culture for streptococcal infection is significant enough to warrant empiric antibiotic therapy without further testing, as the benefits of treatment outweigh the potential risks and costs associated with waiting for laboratory confirmation.

On the other hand, lower scores, such as 0-1 or 2-3, typically suggest that the likelihood of a bacterial cause is low, meaning that antibiotics would generally not be indicated and supportive care would be the preferred management. A history of allergies can guide the choice of antibiotics but does not change the indication for empiric therapy based on the scoring system.