We present a case of anaphylactic shock induced by exercise following celery ingestion. The possible mechanism of food-dependent exercise induced anaphylaxis (FDEIA) and the laboratory tests for its diagnosis are discussed. We evaluated spontaneous, celery–allergen-induced, and anti-FcεRI-antibody-induced histamine release from basophils obtained from the patient, 2 celery-allergic controls, and 3 healthy controls. Buffers of increasing osmolarity were used to mimic conditions of vigorous physical exercise. Only the patient’s basophils showed an increase in spontaneous, anti-FcεRI antibody-induced and allergen-induced histamine release under physiological conditions and with
slightly increased medium osmolarity. To our knowledge, this is the fi rst report on the possible role of increased histamine releasability in the pathogenic mechanism of FDEIA. We suggest that FDEIA results from increased histamine releasability triggered by physical effort after exposure to a sensitizing food allergen.

Key words: Food-dependent exercise-induced anaphylaxis. Histamine release.