D1.292 - Anaphylaxis After Roasted Sunflower Seed Consumption in an Adult: A Case Report

Background

Food allergies can cause severe systemic reactions in adults. Although seeds are widely consumed, sunflower seed allergy is rare and may unexpectedly lead to anaphylaxis. Heat-stable seed proteins may play a critical role in such reactions.

Case Presentation

A 47-year-old male presented to the emergency department with dyspnea, diaphoresis, cough, eyelid edema, and generalized erythema shortly after consuming roasted sunflower seeds. Symptoms resolved after treatment with methylprednisolone and nebulized therapy, without the use of adrenaline. He had no relevant comorbidities but reported asthma and allergic rhinitis symptoms predominantly triggered by pollen exposure.

Laboratory evaluation revealed total IgE of 289 IU/mL, eosinophil count of 0.21 ×10⁹/L, and serum tryptase level of 3.3 µg/L. Specific IgE was positive for hazelnut (2.74 kUA/L), grass pollen (1.76 kUA/L), fruit mix (1.34 kUA/L), and orange (1.46 kUA/L). Skin prick testing showed sensitization to Dermatophagoides farinae, Dermatophagoides pteronyssinus, Blattella, tree pollen mix, red oak, Secale cereale, pistachio, hazelnut, and latex.

Prick-to-prick testing demonstrated positive reactions to raw hazelnut (3×3 mm), roasted hazelnut (3×3 mm), roasted sunflower seed (4×4 mm), and sunflower seed shell (3×3 mm), despite the patient having taken a long-acting antihistamine the day before testing. Although prick-to-prick testing was positive for hazelnut, the patient tolerated hazelnut without symptoms.

The packaged sunflower seeds consumed contained sunflower kernels, salt, and wheat flour, with potential cross-contamination from multiple nuts, seeds, and other allergens during production. The patient was advised to avoid nuts and seeds, prescribed an adrenaline auto-injector, and educated on its use. Molecular component-resolved diagnostics were planned.

Conclusion

This case was considered anaphylaxis triggered by roasted sunflower seed consumption. Positive prick-to-prick reactions to sunflower seed and its shell, together with clinical history, supported sunflower seed as the primary trigger. Tolerance to hazelnut despite positive testing highlighted a discordance between sensitization and clinical reactivity. Heat- and acid-resistant seed storage proteins, particularly 2S albumins and lipid transfer proteins, may underlie such reactions and explain anaphylaxis even after roasting. This case emphasizes the importance of detailed clinical history, careful evaluation of product ingredients and cross-contamination risks, and timely prescription of adrenaline auto-injectors in adult food allergy.