Oral food challenges in clinical practice: a missing element of food allergy diagnosis in Russia

Food allergy is one of the most prevalent allergic conditions, causing reduction in patient quality of life. It is linked with high levels of anxiety due to potential life-threatening reactions, and high economic burden for a healthcare system. Food allergy affects approximately 5 to 10% of children around the world. In Russian Federation the diagnosis of food allergy is primarily based on clinical history, laboratory test results, examination and elimination of suspected food. Meanwhile oral food challenge (OFC) is considered a gold standard of food allergy diagnosis by most of professional bodies nationally and internationally. OFC is a diagnostic procedure involving administration of a causative allergen in gradually increasing amount under a close medical supervision. The method is safe, highly specific and sensitive and is widely used around the world for more than 45 years. The main goals of OFC include food allergy diagnosis and presence of tolerance evaluation, which may result in diet expansion. OFC may also help establishing both, reaction severity and dose needed to elicit reaction, which may further assist with alleviation of patients anxiety. In this paper we discuss existing approaches to the diagnosis of food allergy in Russian Federation and review available recommendations on OFC outlined in international guidelines.

Influence of Antihistamines on Basophil Activation Test in Food Allergy to Milk and Egg

Background: The basophil activation test (BAT) is used to improve the accuracy of food allergy diagnosis. To date, the influence of antiallergic drugs on BAT reactivity is poorly investigated. The aim of the study was to investigate if BAT results were influenced by antihistamine intake for 3 months in a cohort of patients with IgE-mediated food allergy to milk or egg. Methods: A retrospective, single-center, observational study was performed. We enrolled subjects with history of hypersensitivity reaction after specific food ingestion, positive skin prick tests and specific IgEs, concomitant allergic rhinitis, and, contraindication to the double-blind, placebo-controlled food challenge due to personal history of systemic reactions related to the ingestion of culprit food. Validated allergens (α-lactoalbumin, β-lactoglobulin, casein, egg white, and yolk) for BAT were used. Results: Thirty-nine patients with well-documented food symptoms and positive allergological workup were included in the study. BAT was positive in 29 patients. The mean percentages of CD63+ expression to specific culprit allergen did not change after the administration of drugs. Conclusions: This was the first study assessing the effects of oral antihistamines on basophil reactivity in cow’s milk and egg food allergy. Antihistamines do not interfere with BAT results.

Immunoglobulin E‐mediated food allergy diagnosis and differential diagnosis

Food allergies consist of aberrant immunologic, typically immunoglobulin E mediated, reactions that involve food proteins. A clinical history with regard to the suspected food, temporal associations, the duration of symptoms, characteristic symptom complex, and reproducibility in some cases is the key to making an accurate diagnosis. The differential diagnosis includes, for example, other immunologic adverse food reactions, nonimmunologic adverse food reactions, and reactions that involve nonfood items. Skin and blood immunoglobulin E testing for the suspected food antigen can aid the diagnosis in the context of a supportive clinical history. Immunoglobulin E testing for food components may further enhance diagnostic accuracy. Novel testing modalities are under development but are not yet ready to replace the current paradigm. Thus, double-blinded placebo controlled oral food challenge is considered the criterion standard of testing, although unblinded oral food challenges are usually confirmatory.