A group A streptococcal infection is an infection with group A streptococcus (GAS). Streptococcus pyogenes comprises the vast majority of the Lancefield group A streptococci, and is often used as a synonym for GAS.
Group A streptococcus bacteria can be treated with common, inexpensive antibiotics. Penicillin is the drug of choice for both mild and severe disease. For penicillinallergic patients with mild illness, erythromycin can be used,
Diagnosis and Treatment of Streptococcal Pharyngitis Metaanalysis of cephalosporin versus penicillin treatment of group A streptococcal tonsillopharyngitis in children. Pediatrics. 2004; 113(4