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Practitioner's Corner

J Investig Allergol Clin Immunol 2019; Vol. 29(5): 378-398

© 2019 Esmon Publicidad

Manuscript received January 29, 2019; accepted for publication

April 23, 2019.

Guacimara Lucía Hernández-Santana

Allergy Department

Hospital Universitario La Candelaria

Carretera del Rosario s/n

38010 Santa Cruz de Tenerife (Canary Islands) Spain


The patient was diagnosed with coconut allergy and

prescribed a strict avoidance diet and autoinjectable adrenaline.

Nevertheless, she presented with a new episode of anaphylaxis

after inadvertent contact with coconut and required adrenaline

and emergency care.

As she went to Thailand every year and spent some months

there, avoiding coconut was very difficult for her. In Thailand,

coconut is a ubiquitous allergen that is found in sauces, soups,

desserts, and bakery. Therefore, we proposed desensitization.

The protocol and adverse reactions and management are

summarized in theTable. For the first phase, we used commercial

coconut milkAroy-D (60% coconut in water) administered with

dose increases every 24 hours. The second phase was performed

with increasing doses of grated coconut (Hacendado) at 48-hour

intervals, with maintenance of the dose reached safely at home,

until a dose of 6 g was reached. No reactions appeared during

this phase.Amaintenance dose of 6 g of grated coconut (0.4 g of

protein) was prescribed 3-4 times per week. We did not increase

the dose in order to avoid excess fat intake.

Today, 2 years after finishing the tolerance induction

procedure, the patient maintains a regular intake of 6 g of

grated coconut 3-4 times per week and follows an open

diet, thus enabling the intake of any food with coconut as an

ingredient, but not coconut itself. She has not presented new

reactions. In a recent assessment, specific IgE levels to coconut

had decreased to 1.98 kU



Coconut is a tropical fruit obtained from the palm tree


, which belongs to theArecaceae family and is also

knownas treenut.Coconut andproductsobtained fromit arewidely

used in the food industry, as well as in body care products and

medicines. Asian countries are leading consumers and exporters.

Coconut is an oval fruit that measures about 20-30 cm

and weighs around 2.5 kg. It consists of a thick outer shell

(exosperm), a thick intermediate layer (mesocarp), and a

hard inner layer (endocarp) to which the pulp (endosperm) is

attached. The endosperm is the edible part of this white and

aromatic fruit. The internal space houses the coconut water.

The endosperm contains a high percentage of globulins and

a smaller percentage of albumins. The 2 globulins described

as food allergens to date are 7S (Coc n 2) and 11S (Coc n 4),

also known as cocosin [8].

Owing to sensitization to these proteins, cases of cross-

reactivity have been reported between coconut, walnuts,

hazelnuts, and lentils [2,4,5]. Monosensitization to coconut

has also been reported [3].

In the present case, allergenic proteins were not identified,

although taking into account the molecular weights of the

detected bands, some could correspond to subunits of 7S

globulin (156-kDa, 24-kDa, 22-kDa, and 16-kDa). Protein

sequencing may have helped to identify the culprit allergens.

At present, avoidance is the recommended treatment

for coconut allergy. Such a measure could considerably

impact quality of life in some cultures owing to widespread

consumption, with the consequent risk of accidental contact.

Oral tolerance has been successfully induced to treat food

allergy, mainly to milk, egg, and peanut. For other foods, there

are only single case reports. To our knowledge, this is the first

report of desensitization to coconut. As sensitization profiles

vary from patient to patient, we do not know whether patients

sensitized to proteins such as cocosin would respond in the

same way. Data on desensitization to milk and egg suggest

that high titers of specific IgE against casein and ovomucoid

correlate with a poorer outcome of desensitization [9]. A

similar phenomenon may occur with coconut and other foods.

Nevertheless, we think that desensitization should always be

taken into consideration when a patient presents severe allergy

to a food that is widely present in his or her environment.


The authors declare that no funding was received for the

present study.

Conflicts of Interest

The authors declare that they have no conflicts of interest.


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