 The invariable sneezing and falling down in modern English versions have given would-be origin finders the opportunity to say that the rhyme dates back to the Great Plague. A rosy rash, they allege, was a symptom of the plague, and posies of herbs were carried as protection and to ward off the smell of the disease. Sneezing or coughing was a final fatal symptom, and "all fall down" was exactly what happened.
