Eva, 1 year and a half of age, originally from Mayotte, was seen
in the consultation for an acute episode consisting of a
combination of labial edema, pruritus of the oral cavity
and rhinoconjunctivitis after ingesting trout seasoned with
coconut juice (a local recipe).
In the patient’s previous medical history, nothing unusual was
observed except for acute urticaria associated with localized
edema during a massage of the patient’s chest with coconut milk
(local custom).
An allergological workup involved a prick test with natural coconuts (no commercial extract of coconut is available) a labial challenge test and assay of specific IgEs, all of which were positive, while the patch test with coconut was negative.
The workup for airborne allergies and usual foods eaten at her age (in particular trout, other fishes and peanuts) was negative.
Based on these results, the diagnosis of IgE-dependent allergy to coconut was established. Strict avoidance of coconut was recommended; this does not go without producing practical and cultural difficulties upon their return to the island of Mayotte. In fact, in tropical Asian countries, it is a staple food in the traditional diet. It has multiple uses: the liquid contained in the nut is used as a drink and to prepare liqueurs, syrups, sugar and even vinegar by fermentation; the flesh of the nut can be dried to produce jams, sweets, ice cream and pastries; the copra, which is dried coconut meat removed from its shell, can be pressed to prepare coconut oil from which coconut butter is obtained. There are many other uses for this product in the food industry (milks, margarines…), in pharmaceutical practice (suppositories, tablets, ointments), in cosmetology (as an additive in certain soaps, shampoo, creams, lotions and perfumes) and even in heavy industry where it is a component of fuel, detergent and certain insecticides. Consequently, compliance with the recommendation of strict avoidance of allergens will be especially difficult, all the more so if we consider that a coconut allergy is rare.
The rare occurrence of this condition aside, this case illustrates the difficulties in the management of allergy of an ubiquitous food for geographic, economical and cultural reasons.
There is reason to question whether specific desensitization to Cocos nucifera pollen can make it possible to obtain a positive effect on food allergy to coconut and consequently facilitate the management of the rare patients who are allergic to this food, whose cultural practices do not get along with strict avoidance of coconut.