We report a case of a 20-year-old female with long-lasting type 1 diabetes mellitus (DM1), coeliac disease, and episodes of diabetic ketoacidosis (DKA), who presented to the emergency room with severe DKA (glycaemia 53.8 mmol/L, base excess 27.4 mmol/L, arterial pH 6.93), abdominal pain, and frank coma.