Pectin allergy is not very common, but it can be a source of allergy for patients sensitive to cashew and pistachio. Food allergy is estimated to affect 6-8% of children in the United states and it is associated with a risk of anaphylaxis. Despite avoidance to culprit foods, hidden allergens can be a source of food allergy reactions.
Pectin consists of a complex set of polysaccharides that are present in most primary cell walls and help bind cell walls together. It is used as an emulsification agent to thicken or solidify foods such as candy, jelly and jam and smoothies. Pectin also is used in dessert fillings, medicines, sweets, as a stabilizer in fruit juices and milk drinks, and as a source of dietary fiber. Commercial pectin can be derived from apple or citrus fruits. Past cases of reported reactions to pectin have been reported from foods and medications.
Other reports have suggested pectin as the trigger for work-place asthma, rhinitis and dermatitis in patients with cashew allergy. It seems that patients who are allergic to pistachio and cashew have more susceptibility to pectin allergy. The mechanism underlying the cross-reactivity between cashew and pistachio and pectin has not been determined, but it could be related to a novel carbohydrate allergen or cross reaction between proteins in tree nuts and apple or citrus fruit. Pectin should be considered a potential culprit in patients with cashew and pistachio allergy who report allergic reactions to an unknown trigger.
Idiopathic anaphylaxis and allergic reactions to hidden allergens are estimated to affect more than 20,000 patients each year in the U.S. A thorough work up and history could prove useful in identifying the culprit allergen. Patients extremely sensitive to other foods could demonstrate reactions to trace amounts of an allergen in unusual foods, beverages, medications, vaccines and personal care products.
Pectin allergy has been linked to those with cashew and pistachio allergy. When ingested, patients might exhibit symptoms ranging from mild to anaphylaxis. Asthma and rhinitis have been reported with occupational exposure.