ANAPHYLAXIS SECONDARY TO AN EMULSIFIER IN ALMOND YOGURT IN A CASHEW/PISTACHIO SENSITIZED PATIENT

Introduction Pectin is an emulsifier derived from fruits and has been recognized as an occupational aeroallergen exposure. It more recently has been implicated as a food allergen with cross-reactivity to cashew and pistachio. To our knowledge, all published cases of anaphylaxis following pectin ingestion have occurred in cashew or pistachio sensitized patients. Case Description A 6-year-old male with a known food allergy to peanut and avoidance of cashew/pistachio due to sensitization developed a rash and emesis immediately after ingestion of strawberry flavored almond yogurt and peaches. The patient was seen by an outside allergist who performed skin prick testing (SPT) to strawberry, almond, peach, and a sample of the yogurt. All SPT's were negative, apart from positive SPT to the yogurt itself. The patient was referred for a second opinion. Review of yogurt ingredients identified citrus pectin as a possible culprit. We performed SPT to the fruit and seed of lemon, orange, and grapefruit. SPT's to orange and lemon seeds demonstrated sensitization of 30mm/53mm (wheal/flare) and 24mm/35mm respectively with negative SPT's to the fruits and grapefruit seed, as suspected as the fruits without seeds were previously tolerated. Therefore, pectin was thought to be the likely trigger of the episode. Discussion To our knowledge, this is the fifth described anaphylactic reaction following ingestion of pectin derived from citrus fruit. All identified patients have had known sensitization to cashews or pistachios. Cross-reactivity should be explored in cases of unexplained anaphylaxis in patients with known food allergies. The clinical management of these patients remain a practical dilemma.