Allergic reactions in adults with a food allergy occur frequently, are often severe and are associated with high costs. A striking, new finding was that non-adherence to dietary advice occurs in approximately one-third of adult patients, adding to the significant socioeconomic and psychosocial burden of food allergies. These were the key findings in the PhD research of Astrid Versluis who defended her thesis in Utrecht on January 10, 2023.

Food allergy is an adverse immune response to food proteins that can cause reactions in skin, gastro-intestinal and respiratory tracts and the circulatory system, some being potentially life-threatening. The prevalence of food allergy in European adults ranges from 0.3-6 percent of the population, depending on the country. There is no cure for food allergy and accidental allergic reactions continue to occur in the daily life of patients. The key interventions are elimination of the culprit food from the diet and treatment of accidental allergic reactions with emergency medication (such as adrenaline). Therefore, having a food allergy poses a significant socioeconomic and psychosocial burden to patients and impairs quality of life. In her PhD research, Astrid Versluis (clinical nurse specialist at the Department of Dermatology & Allergology, UMC Utrecht) investigated the frequency, severity and impact of accidental allergic reactions, factors related to occurrence of these reactions, and adherence to dietary advice in adults.

Accidental allergic reactions

The research by Astrid Versluis and colleagues showed that accidental allergic reactions in adults occur frequently, are often severe and are associated with high costs. For example, in a study from UMC Utrecht 46 percent of patients with a known food allergy experienced on average two accidental food allergy reactions per year. In addition, in two other studies it was shown that in respectively 32 and 57 percent of the cases, these accidental allergic reactions were severe. Finally, direct and indirect medical costs were sevenfold higher in patients with accidental reaction than in patients without such reactions. The total annual cost for all accidental food allergic reactions in the Netherlands are estimated to be around € 160 million, illustrating a significant economic burden.

Risk factors

The occurrence of a food allergic reaction is affected by many factors, and these can be related to the patient, healthcare and food. Important patient-related factors are age, social barriers to the disclosure of their allergy (e.g. in restaurants) and non-adherence to the elimination diet. A major healthcare-related factor is the degree to which clinical practice is tailored to the individual patient. An important food-related factor is the absence of harmonized regulation regarding precautionary allergen labeling (e.g. ‘may contain peanuts’).

Dietary advice often ignored

Patients that do not comply with an advised elimination diet are at increased risk of accidental allergic reactions. Non-adherence to a given dietary advice appears frequently: in one of the studies by Astrid Versluis, in 41 adults undergoing in total 58 food challenges, the adherence to the provided dietary advice was relatively poor: in patients with a positive food challenge adherence was only 31 percent (18 out of 58). Factors associated with non-adherence were misremembering of the dietary advice, low quality of life on the domain ‘emotional impact’ and the need for diet change after a positive food challenge. These outcomes suggest that it is important that healthcare professionals more often apply adherence-enhancing strategies to improve dietary adherence.

Astrid Versluis concludes: “Our results indicate that patients with food allergies frequently experience accidental allergic reaction in their daily lives. The occurrence of these reactions is affected by many factors, including non-adherence to dietary advice. This indicates that the current standard follow-up care is insufficient. We therefore recommend to tailor healthcare in these patients even more to the individual patient, for example with regard to education and with support of behavioural and psychosocial aspects. Furthermore, improvement of food labelling regulation is needed. The ultimate outcome should be to reduce the occurrence of accidental allergic reaction in daily life, improve the quality of life of people with food allergies and to the reduce cost of healthcare.”