Coconut allergy is becoming a more common concern among parents of children with food allergy. Coconut has been increasing in the US diet and it is an alternative to cow’s milk for those who are allergic. Coconut is a common food allergen seen in skin care products. It is commonly seen in natural moisturizers.
Coconut (Cocos nucifera) is a fruit and not a tree nut. Coconut is commonly tested in tree nut panels and sensitization has been reported between 20-30% in those allergic to tree nuts.
Diagnostic criteria for coconut allergy have not been well established in regards to IgE blood testing and skin testing.
A recent study published in the Annals of Allergy Asthma and Immunology examined the diagnostic cutoffs for specific coconut allergy.
The probability of allergy with a positive skin test result was approximately 50% and with specific IgE it was 60%. A skin test wheal size of 9 mm or sIgE of 58 kU/L, there is a 95% probability of a reaction. Cosensitization with tree nuts, legumes and seeds was common. Macademia nut had the strongest correlation with coconut.
In the study, a higher risk of coconut allergy was seen in the Asian and African American patients. This might reflect more frequent inclusion of coconut in the diet or in topical application. Topical exposure has been associated with an increased risk of food allergy. Higher rates of allergy were seen in those who used coconut in skin and hair care products.
Coconut can be associated with a wide range of reactions in children. Topical, breastfeeding and ingestion exposures are associated with the reactions. Coconut based products might be a source of sensitization and doctors should consider the risk of use in patients who have eczema or atopic dermatitis. Clinical history, skin testing and IgE labwork should all be used to help diagnose coconut allergy.