Sahota, R.

Abstract Food allergy reactions emerging after organ transplantation, particularly following lung transplantation, are uncommon but pose significant clinical challenges. While most documented cases have involved liver transplants and pediatric patients, instances in lung transplant recipients remain rare. Here, we present a case of acute bronchospasm triggered by hummus ingestion, requiring mechanical ventilation in a post-lung transplant patient. This case underscores the need for heightened awareness of potential allergenic reactions in transplant recipients and emphasizes the importance of prompt recognition and management of such reactions in the critical care setting. A 61 year old female experienced an acute respiratory event requiring emergent intubation shortly after ingesting hummus. Initial treatment included duonebs and bronchoscopy, revealing a normal airway architecture but notably stiff lungs. She responded to epinephrine administration. Post-event serum tryptase was within normal limits, suggesting the reaction was primarily respiratory in nature. Despite having a known peanut allergy in her organ donor, her own history was negative for peanut IgE reactivity. Subsequently, she underwent extensive blood IgE testing, confirming negative IgE to peanut, yet yielding positive or equivocal results to chickpea and sesame. Skin testing was positive for “Sabra Snack Hummus,” suggesting reactivity. Prick-to-prick skin testing with chickpea, however, was negative. Additionally, IgE component testing identified Ara h2, a peanut protein with potential cross-reactivity to other legumes, including chickpeas. Managing peanut allergy in post-transplant patients requires careful consideration to prevent severe allergic reactions. Screening is crucial when a donor has a known food allergy, as this can help identify potential allergic responses due to transferred donor immune cells. If a peanut allergy arises post-transplant, strict avoidance of peanuts and cross-reactive allergens, such as certain nuts and legumes, is advised. Transplant recipients with confirmed peanut allergies should carry an epinephrine auto-injector to immediately treat potential anaphylaxis. The pathophysiology of post-transplant food allergies remains under investigation. One theory suggests that donor-derived B lymphocytes producing peanut-specific IgE may enter the recipient's circulation, leading to sensitization. Alternatively, IgE-sensitized mast cells and basophils within the transplanted tissue may react directly in the recipient's lungs or lymph nodes. Another possibility is IgE already attached to mast cells in the bronchial mucosa or lung tissue, heightening allergic reactivity. The safest management includes avoiding all nuts, chickpeas, and sesame seeds, with an epinephrine auto-injector for emergency use. This case underscores the importance of monitoring for food allergies in transplant recipients, especially when the donor has a history of allergies.