Case 24. A woman aged 46 presents with a hot, swollen area of hand for the past week, and a 2 day history of rigors, fever and nausea. On examination of the area, it is superficial inflammation, which is oedematous and 'like orange peel'. Cultures on blood agar show b-haemolysis, and Lancefield grouping shows type 'A' What is the causative agent, and what is the disease?
Group A b-haemolytic streptococci - Erysipelas