Episode 225: Group A Strep

Group A strep in the pediatric ED: from strep throat to invasive disease and toxic shock. Host: Ellen Duncan, MD, PhD Brian Gilberti, MD https://media.blubrry.com/coreem/content.blubrry.com/coreem/Group_A_Strep.mp3 Download Leave a Comment Tags: Infectious Diseases, Pediatrics Show Notes Background Group A strep = Streptococcus pyogenes — gram-positive organism that colonizes the pharynx, but also the perianal and genital mucosa (worth remembering when the source isn’t the throat). Extremely common. The episode cites an estimated ~289 million cases/yr of strep pharyngitis in children 5–14 (NIH). For a U.S.-specific, verifiable anchor: the CDC estimates strep throat drives ~5.2 million outpatient visits/yr in people <65. No true beta-lactam resistance. GAS remains uniformly susceptible to penicillin and amoxicillin. Note this is not true for macrolides/clindamycin — roughly 1 in 3 invasive isolates are now erythromycin/clindamycin resistant. Pathophysiology — the throughline Exotoxins (superantigens) tie the whole spectrum together — they drive scarlet fever, streptococcal toxic shock syndrome (STSS), and are implicated in the Kawasaki overlap discussed below. The organism is the same from a sore throat to a life-threat; what changes is host response and toxin burden. Clinical Presentation Core findings: tonsillar inflammation/exudate, tender anterior cervical lymphadenopathy, fever. Classic strep tells to hunt for: Palatal petechiae Strawberry tongue Perioral pallor Scarlet fever — fine, sandpapery rash, typically starts on the trunk and spreads outward; later desquamation of the fingers and toes. Extra