Exercise-induced anaphylaxis: An update

Abstract

Exercise-induced anaphylaxis (EIAn) is a rare and potentially fatal syndrome associated with exercise. It is the most serious and potentially life-threatening hypersensitivity phenomenon for athletes of all sports. Food-dependent EIAn (FDEIAn) shares the same symptoms, but ingestion of foods 2-3 h prior to exercise is crucial for its presentation. Attacks may seldom occur also if food ingestion is made 2-3 hours after exercise. Concomitant use of drugs, particularly aspirin and non-steroidal anti-inflammatory drugs, can worsen the clinical presentation. Clinical manifestations cover a wide range of symptoms, from pruritus to dyspnoea to vascular collapse. Differential diagnoses must be investigated when symptoms are unusual. Several pathogenetic theories have been formulated but the rarity of EIAn has not facilitated the efforts of scientists to find pathophysiological and immunological mechanisms that may account for these conditions. Diagnosis is mainly clinical and can be difficult. Validated protocols including skin prick testing together with food-exercise challenges, laboratory investigations looking for specific immunoglobulin E or through allergy molecular diagnostics are often required. Preventative measures are of fundamental importance, in particular regarding education of patients, family/ carers, trainers and teammates. Use of adrenaline autoinjectors is also fundamental and their correct use must be taught to patients, doctors and nurses. Pharmacological preventative measures are not supported by sufficiently powered studies. Further research will be needed to investigate deeper the complexities of EIAn.