Quality-of-life assessment may support the correct diagnosis of adult wheat allergy

Wheat is a frequent cause of food-induced allergic reactions in adults. In this study we aimed to assess the diagnostic value of skin prick test (SPT), specific immunoglobulin E (sIgE), but also quality of life in wheat-sensitized and allergic patients.

In this prospective, clinical study 80 patients were screened for eligibility. Subsequently, 36 wheat-sensitized patients underwent oral food challenges (OFCs) with supraphysiological amounts of gluten at rest and in combination with exercise. The challenge was stopped when objective symptoms occurred. Prior to the challenge, sIgE measurement and a SPT were conducted. The Food Allergy Quality of Life Questionnaire (FAQLQ), Food Allergy Independent Measure (FAIM), and Beck Anxiety Inventory (BAI) were used to assess the quality of life, perceived disease severity, and anxiety of the patients.

The OFC was performed with increasing amounts of gluten reaching a supraphysiological level. 24 patients (67%) were OFC positive with 21 reacting at rest. 3 patients reacted after the implementation of exercise. 60% of patients with a self-reported exercise dependency reacted in the OFC at rest. 8 of 21 patients who reacted at rest were rechallenged with exercise and lower doses of gluten, of which 5 reacted again. Exercise lowered the reaction threshold by 50% in these 5 patients. OFC-positive patients had stronger sensitization to gluten and its constituents and showed higher impairment in their quality of life and perceived burden of disease than OFC-negative patients. The receiver operator characteristics model including gluten SPT, omega-5-gliadin sIgE, and the FAIM score to predict OFC positivity yielded a 95.2% sensitivity and 83.3% specificity. Males displayed a higher degree of sensitization, but females had higher FAQLQ and FAIM scores.

Although a high rate of exercise dependency was reported, most reactions were elicited at rest when the amount of gluten was upscaled. However, the eliciting amount and reaction threshold was lowered in the presence of exercise. Food allergy-related quality-of-life data can indicate psychological impairment due to the disease but may also serve as a patient-reported outcome tool which can support the diagnostic accuracy of wheat allergy.