Exercise-food challenge test in patients with wheat-dependent exercise-induced anaphylaxis.

BACKGROUND

Wheat-dependent exercise-induced anaphylaxis (WDEIA) is a severe and potentially life-threatening food allergy. Diagnosis of WDEIA is challenging because reactions are not always reproducible.

OBJECTIVE

This study aimed to evaluate the positivity rate of exercise-food challenge test at our allergy unit in order to confirm the diagnosis, and to investigate the effect on the episode of reactions after the test.

METHODS

This retrospective evaluation included patients aged 5-60 years who presented at the pediatric and adult allergy units of Siriraj Hospital during 2014-2018 with a convincing history of WDEIA and who underwent a 4-day exercise-food challenge test. Demographic data, challenge test result, and episodes of the reaction before and after the challenge test were obtained.

RESULTS

Fourteen of the 17 patients that were enrolled were included in the analysis. The 3 excluded patients were found to have IgE-mediated wheat allergy. Median age and time to diagnosis was 18.3 years (range: 10.5-43.4) and 1.8 years (range: 0.3-6.2). History of recurrent acute urticaria before the onset of anaphylaxis was reported in 5 patients (35.7%). Exercise-food challenge test was positive in 10 patients (71.4%). Median mean number of exacerbations per year before and after the confirmation test was 2 (range: 1-10) and 1 (range: 0-3), respectively.

CONCLUSIONS

For WDEIA, time to diagnosis was delayed, and one-third of patients had recurrent acute urticaria proceeding anaphylaxis onset. Our exercise-food challenge test could be utilized safely in both children and adult and able to elicit symptoms in two-third of patients.