Coconut Allergy Revisited
Katherine Anagnostou 1,2
1Department of Pediatrics, Section of Immunology, Allergy and Rheumatology, Texas Children’s Hospital,
Feigin Center, 1102 Bates Avenue, Suite 330, MS: BCM320, Houston, TX 77030, USA;
Aikaterini.Anagnostou@bcm.edu; Tel.: +1-832-824-1319
2Department of Pediatrics, Section of Immunology, Allergy and Rheumatology, Baylor College of Medicine,
Houston, TX 77030, USA
Received: 19 September 2017; Accepted: 28 September 2017; Published: 29 September 2017
Despite concerns voiced often by food-allergic patients, allergy to coconut is rare, not
directly associated with nut allergy and few cases are reported so far in the literature. We present an
interesting case of coconut allergy in a child that was previously tolerant to coconut and regularly
exposed via both the skin and gastrointestinal route.
Keywords: food allergy; coconut allergy; anaphylaxis; allergic reaction; skin prick tests
A common concern of food allergic patients (especially those allergic to nuts) is whether they can
safely consume coconut products. Despite coconut allergy being rare, there is a misconception that
if a patient is allergic to nuts, they are at high risk of experiencing allergic reactions to coconut; as a
consequence, nut-allergic patients are not uncommonly advised to avoid coconut.
Coconut (Cocos nucifera) is a fruit (not a nut) that belongs to the Aracaceae (palms) plant family.
The term is derived from the 16th-century Portuguese and Spanish word ‘coco’ meaning ‘head’ or
‘skull’. The oil and milk derived from coconut are commonly used in cooking and frying, as well as in
soaps, cosmetics and other skin care products.
Reports of immunoglobulin E (IgE)-mediated coconut allergy are rare and only a handful of cases
have been reported in the literature in adults and children [
]. However, despite the low prevalence
of coconut allergy, reactions tend to be systemic and all cases reported so far have involved anaphylactic
reactions. In the United States, coconut must be disclosed as an ingredient on package labels.
We report a case of coconut allergy in a school-age child, who presented with a history of recurrent
allergic reactions to coconut. At the age of 6 years, the patient experienced generalized urticaria to
coconut oil applied on the skin. Prior to this reaction, coconut oil had been applied multiple times
a week on the skin, since the age of 2 weeks old, without any problems. The patient was also
eating coconut regularly without allergic reactions. A second episode of skin reaction (widespread
hives) was noted two weeks after the ﬁrst one, again following application of coconut oil on the
skin. Soon after these two episodes, the patient complained of a ‘scratchy throat’ after eating coconut.
The parents also report one episode when the child ate a few spoonfuls of coconut ice-cream and,
20–30 min later, complained of throat itching and severe abdominal pain with subsequent vomiting
and diarrhea. There were no respiratory symptoms on that occasion. The reaction was treated
successfully with antihistamines. At the age of 6 and a half, the patient ate an oatmeal/raisin cookie
that also contained coconut. Throat itching developed and was treated successfully with antihistamines.
More recently however, while at school, the patient inadvertently ate another oatmeal/raisin cookie
containing coconut and developed a scratchy throat. This was followed by vomiting and wheeze. Both
bronchodilators and antihistamines were administered and the patient was taken to a medical facility.
By the time of arrival, the wheeze had resolved and all other symptoms of anaphylaxis had also settled,
so no further treatment was required.
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Children 2017,4, 85 2 of 3
In terms of atopic background, the patient did not report any other food allergies and had
been eating peanuts, almonds, hazelnuts, cashews, pistachios, pecans and walnuts regularly without
any problems or reactions. With regards to nasal allergies, parents reported mild, occasional, nasal
congestion, not requiring treatment. No food pollen syndrome symptoms to any fresh fruits or
raw vegetables were reported. The child had experienced allergic reactions to cats in the past with
skin and upper respiratory/eye symptoms. With regards to respiratory symptoms, bronchodilators
were prescribed at the age of 6 years, following an upper respiratory infection with persistent
cough. These were not required on a regular basis. Mild infantile eczema was noted shortly after
birth, mostly in the form of dry skin, for which coconut oil was applied. On examination in clinic,
mild ﬂexural eczema was noted on the antecubital fossae and popliteal fossae, well controlled with
Skin prick testing to coconut commercial extract showed a strongly positive result (20 mm wheal).
Cat and dog skin test results were also positive (see Table 1below).
Skin prick testing results. Measurements represent the mean of 2 diameters. Test results to
other aeroallergens (including pollens and house dust mite) were negative (data not shown).
Allergen Wheal/Flare (mm)
Control positive skin prick test 12/20
Control negative skin prick test 0/0
Cat 15/20 P
Dog 6/8 P
Mold mix #1 4/4
Mold mix #2 3/3
P: Pseudopod formation.
Coconut allergens have previously been identiﬁed as Coc n2, a 7S globulin; and Coc n4, an 11S
]. Cross-reactivity between coconut and tree nuts/lentils has been described in the
literature (due to the 7S and 11S globulins) [
], but a retrospective study from the US has previously
reported that children with sensitization or allergy to peanuts or tree nuts are not more likely to be
sensitized or allergic to coconut [
]. We note that the ofﬁcial allergen nomenclature subcommittee, the
International Union of Immunological Societies (IUIS, http://www.allergen.org), currently includes
only the 7S globulin allergen, also known as vicilin-like, and named Coc n1 for coconut.
What is interesting in our case is that coconut allergy developed in a child that was regularly
exposed to coconut allergen previously without reaction. This involved skin exposure in the form of
coconut oil since the age of two weeks and subsequently also via the oral route, tolerating coconut and
coconut-containing products, until the age of 6 years. This pattern of coconut allergy development has
not been reported previously in children, to our knowledge. It has been shown however, for peanut
allergy, that sensitization may occur via the skin (without concurrent oral exposure), due to topical
exposure from a very early age [
]. In our case, there was conﬁrmed oral tolerance to coconut for
some years prior to reactions occurring.
In summary, we report a case of coconut allergy, presenting in a 6-year-old child, despite previous
regular exposure to coconut via both the cutaneous and oral route. Our knowledge in coconut allergy is
limited as only a very small number of patients are affected. Given the increasing use of commercially
available coconut products, it is important to be aware of the allergenic potential of coconut, even if
the allergen has previously been tolerated.
Conﬂicts of Interest:
The authors declare no conﬂict of interest. The founding sponsors had no role in the design
of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, and in the
decision to publish the results.
Children 2017,4, 85 3 of 3
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