In rare cases, additives such as dyes or preservatives in food can trigger severe pseudoallergic reactions in the skin, airway or gastrointestinal tract. While the vast majority of the population does not react to these E number-coded substances, patients with chronic urticaria may achieve a significant reduction in symptoms by avoiding food additives.
This insight was revealed again in a review paper on pseudoallergic reactions to additives, which recently appeared in Bundesgesundheitsblatt, the German Federal Health Bulletin. “This is why mandatory labelling of food additives is very important for these patients”, says Prof Torsten Zuberbier, Chairman of the European Centre for Allergy Research Foundation (ECARF) and co-author of the study. “The EU directive enables them to identify and avoid specific additives that trigger pseudoallergic reactions.”
In one of his earlier studies with patients suffering from chronic urticaria, Prof Zuberbier found that symptoms such as hives and itching subsided completely or almost entirely in 73 per cent of the patients after just two weeks on a pseudoallergen-free diet. At the follow-up examination six months later, the chronic urticaria had resolved completely in 46 per cent of the patients. All but one experienced long-term improvement in their symptoms; after the six months, half of the patients were able to tolerate a full, balanced diet.
Pseudoallergies to additives generally cannot be determined through the usual skin and blood tests. For this reason, an exclusion diet and, if applicable, in-patient provocation testing are recommended in suspected cases.
Zuberbier T, Hengstenberg C; Verstecktes Risiko im Kleingedruckten? Einige Zusatzstoffe können pseudoallergische Reaktionen auslösen (Hidden risk in the small print? Certain additives can trigger pseudoallergic reactions). In: Bundesgesundheitsblatt 2016 · 59:777–782