RESUMEN
Group A ß-haemolytic Streptococcus or Streptococcus pyogenes is a gram-positive coccus that tends to grow in chains. Streptococcus pyogenes is the cause of many important human diseases, ranging from pharyngitis and mild superficial skin infections to life-threatening systemic diseases. Infections typically begin in the throat or skin. Mild Streptococcus pyogenes infections include pharyngitis (strep throat) and localised skin infections (impetigo). Erysipelas and cellulitis are characterised by multiplication and lateral spread of Streptococcus pyogenes in deep layers of the skin. Streptococcus pyogenes invasion and fascial involvement can lead to necrotising fasciitis, a life-threatening condition. Scarlet fever is characterised by a sandpaper-like rash in children with fever and is caused by a streptococcal toxin. Severe infections that lead to septicaemia or toxic shock syndrome are associated with high mortality. Autoimmune reactions cause characteristic syndromes such as rheumatic fever and nephritis. Epidemiology, disease presentation, diagnosis, and treatment of paediatric patients in Hong Kong with group A ß-haemolytic Streptococcus are reviewed in this article. Streptococcus pyogenes disease is readily treatable, as the organism is invariably sensitive to penicillin. Delayed treatment of this common childhood pathogen is associated with significant mortality and morbidity.