An uncommon presentation for a common problem.

One of the axioms of general practice is that 'common things present commonly', both in the community incidence of disease and in the symptoms with which illnesses usually present. This was somewhat enigmatically put by a renowned neurologist at the Mayo Clinic: "When you hear hoof-beats, why think of zebras?". A most difficult, yet important feat for the GP is to keep on the alert for the uncommon symptom of a common cause, and the common symptom with an uncommon cause.