Background Acute Streptococcus pyogenes infections may present under various forms, such as pharyngitis, scarlet fever, pneumonia, meningitis, cellulitis or impetigo. Toxigenic infections can result in necrotizing fasciitis, myositis and streptococcal toxic shock syndrome. Following acute infections caused by S pyogenes, patients are also at risk for developing immune-mediated post-streptococca...