Group A Streptococcus bacteria can cause various pyogenic infections such as tonsillitis, pharyngitis, scarlet fever, impetigo, erysipelas, cellulitis and pneumonia. Most group A Streptococcus infections in children are mild and respond positively to treatment with antibiotics. However, some children develop severe infection accompanied by complications such as sepsis and will require urgent treatment, which may include non-invasive or invasive ventilation and the administration of fluids and vasoactive agents. In some instances, for example if there are no beds available in the paediatric intensive care unit, these interventions may be undertaken in a ward setting. This article gives an overview of group A Streptococcus infection, including two rare but severe complications, streptococcal toxic shock syndrome and necrotising fasciitis. It uses a fictionalised case study to examine the management of the deteriorating child with suspected group A Streptococcus infection, including respiratory support, haemodynamic support and symptom management.