Food-dependent exercise-induced anaphylaxis to flaxseed

Abstract

The present paper reports on a 26-year-old atopic patient suffering from seasonal rhinoconjunctivitis and flexural eczemas. On two occasions, he experienced nausea, generalized urticaria and dyspnea within 2 h after consumption of a wholemeal roll and subsequent exercise (football training or walking). In each case, the episode necessitated intravenous emergency therapy with an antihistamine and a corticosteroid. In order to elucidate the two exercise-induced anaphylactic events we performed prick tests and the radioallergosorbent test (RAST) with the ingredients of the wholemeal roll. Only flaxseed gave positive results. In addition, we performed an exercise test on a bicycle ergometer (15 min at 150 W) and an oral challenge test with foods, using a double-blind and placebo-controlled study. Only oral challenge with a teaspoon of flaxseed with additional exercise on the bicycle ergometer elicited itching, urticaria, nausea, coughing and dyspnea. The oral challenge with flaxseed followed by exercise induced immediate-type reactions and, thus, led to the diagnosis of food-dependent exercise-induced anaphylaxis to flaxseed.