Streptococcal pharyngitis, infectious mononucleosis, or both? A diagnostic dilemma in pediatric pharyngitis.

Infectious mononucleosis (IM) is a common cause of pharyngitis in children, particularly among adolescents. IM is a self-limiting condition, and differentiating it from other causes of pharyngitis that require treatment is key to its management. One such condition is group A streptococcal (GAS) pharyngitis, which can be complicated by acute rheumatic fever if left untreated. In this report, we present a case of suspected IM with a positive GAS rapid antigen detection test, highlight the evidence surrounding these two conditions, and discuss the clinical dilemma of performing GAS testing in patients with an IM-like presentation.