D2.99 - The mysterious cases of anaphylaxis to döner kebab in Germany/Switzerland with subsequent tolerance in Türkiye: an unwelcome guest causes trouble

Introduction

We report on two cases of anaphylaxis to döner kebab that illustrate the difficulties in the diagnosis of food allergy.

History

Case 1:

A 58-year-old Turkish man described a 20-year history of recurrent facial and palmar pruritus with erythema, temporarily linked to meals but without an identified trigger. Several years ago, he required emergency care in Switzerland after dining a döner kebab. Subsequently, he tolerated it multiple times in Türkiye. Döner consumption in Switzerland continued to trigger allergic symptoms.

Case 2:

A 66-year-old Turkish woman presented to our ER with dyspnea, angioedema and flushing immediately after consuming a döner kebab in a bordering German town. During the allergy evaluation, she reported subsequent tolerance of döner kebab in Türkiye, but ongoing reactions in Switzerland and Germany. Further history revealed oral burning, angioedema of the tongue and mild dyspnea triggered by lentils and white beans while green beans, peas, nuts and peanuts were tolerated.

Allergy Evaluation

Case 1:

Skin prick tests (SPT) to a panel of aeroallergens and relevant foods were strongly positive to döner meat and soy; others were negative. ImmunoCAP and ISAC confirmed type-I sensitization to soy as well as to Gly m 5 and Gly m 6, but not to Gly m 4.

Case 2:

SPT to a panel of aeroallergens, foods and all ingredients of the döner kebab were strongly positive to döner meat, soy, soybean flour, chickpeas, lentils and white beans. ImmunoCAP and ISAC revealed type-I sensitization to soy, white beans, lentils, Gly m 5, Gly m 6 and Ara h 3 with no sensitization to Gly m 4.

Conclusion:

Soy was declared by the restaurant on case 2 and confirmed as a standard ingredient by the döner meat manufacturer in Southwest Germany. Further research showed that soy addition to döner meat was banned in Türkiye in 2012 but remains in use in Germany and Switzerland. This regulatory difference fully explains the patients' lack of reactions in Türkiye.

Our two patients underscore the difficulties in diagnosing food allergies after reactions to dishes with multiple ingredients and/or to processed foods. Testing with the native ingredients is an essential step in the diagnostic process when the cause remains elusive.

Soy should be considered as a potential culprit in unexplained food-induced anaphylaxis.