Systemic anaphylaxis induced by physical exertion: a case report.

Anaphylaxis is a systemic reaction which can be very dangerous in many patients. In addition to the most common antigens (drugs, venoms, foods), physical exercise can provoke anaphylaxis in the sensitized patients. The mechanism of this reaction is still unknown. In this report, we describe a case of exercise-induced anaphylaxis in a 25 year old female who had experienced two syncopal attacks during strong physical activity. On other occasions she had noticed that prolonged work would cause urticaria, pruritus and numbness. During hospitalization, on two occasions a treadmill stress test induced bronchial spasm, urticaria and hypotension. We believe that the association of urticaria and anaphylaxis would suggest the possible presence of a vasoactive substance released from the mast-cells and basophil leucocytes.