I referred your question to Dr. Scott Sicherer, an internationally recognized expert in food allergy and Deputy Editor of JACI: In Practice. His response is below.
“It is also my understanding that coconut oil may be cold-pressed. But it is also my understanding that it contains little protein. Coconut allergy itself is uncommon, but I can see how having such large skin tests raises concern and is dissuading a coconut food challenge. I cannot find any convincing case reports of allergic reactions to coconut oil (or palm oil) and so it seems unlikely it would be an issue. Allowing ingestion of products with coconut oil would be very helpful for expanding the diet. Given the past anaphylaxis and the very large skin test to coconut, it would be easy and probably reassuring to let the child eat the coconut oil product under your supervision as a food challenge. As for palm oil, I would typically answer that it is not a concern. “
I was able to find some references to coconut oil allergy, including a 1994 report of an infant reacting to human milk containing coconut (1,2,3). I was not able to access the full texts of any of these reports, but the abstract from Couturier et al describes skin testing and measuring specific IgE to coconut present in the milk. The Shaffer et al article may have been based upon patch testing but I was not able to access this as well.
There are a few questions from the Ask the Expert archives related to coconut oil allergy. I have copied one from 2012 below.
1. Couturier, P., et al. "A case of coconut oil allergy in an infant: responsibility of" maternalized" infant formulas." Allergie et immunologie 26.10 (1994): 386-387.
2. Shaffer, Kristina K., et al. "Allergenicity and cross-reactivity of coconut oil derivatives: A double-blind randomized controlled pilot study." Dermatitis 17.2 (2006): 71-76.
3. Tella, R., et al. "A case of coconut allergy." Allergy 58.8 (2003): 825-826.
Should a person with coconut sensitivity avoid coconut oil?
Unfortunately, I cannot give you a definitive answer to your inquiry. I can, however, refer you to articles which discuss this issue, but I am not aware of any study which defines this situation adequately enough to allow us to give you complete assurance one way or another as to whether or not a patient truly sensitive to coconut would react to the ingestion of coconut oil.
What we do know is that coconut allergy per se is very rare. In Paul Hannaway's text (1), which is an extensive review of food allergy, he could only find three documented cases of coconut allergy. I am only aware of one case of a putative reaction to coconut oil (see abstract copied below). The Food Allergy and Anaphylaxis Network (FAAN) collected data on 5,149 patients, and found only 4 individuals who reported allergy to coconut (2). With these small number of cases, it is difficult therefore to come to a conclusion.
There are data on the protein content of coconut oil. Crude oil contains 250 mcg per ml of protein, bleached and filtered oil contains 144 mcg per ml, and if the oil is deodorized, 7.9 mcg per ml (3), but the clinical significance of these figures remains undetermined.
In summary, based upon the available literature, we can only conclude that IgE-mediated reactions to coconut are rare, and that reactions to coconut oil are probably even more so, but because there is at least one reported case, we cannot rule out the possibility of such a reaction in a patient who is truly sensitive to coconut.
Finally, the above response assumes that you were inquiring about IgE-mediated reactions to coconut. Coconut oil is known to be antigenic as far as its predisposition to cause contact dermatitis (see abstract copied below from "Contact Dermatitis"). This can evidently be via an immunologic as well as an irritant mechanism.
Thank you again for your inquiry and we hope this response is helpful to you.
(1) Hannaway PJ. On the nature of food allergy. Copyright 2007; Page 111. Published by Lighthouse Press.
(2) Sicherer SH, et al. A voluntary registry for peanut and tree nut allergy: characteristics of the first 5,149 registrants. J Allergy Clin Immunol 2001; 108(1):128-132.
(3) Cravel, et al. Allergenicity of refined vegetable oils. Food and Chemical Toxicology 2000; 38:385-393.
Allerg Immunol (Paris). 1994 Dec;26(10):386-7.
[A case of coconut oil allergy in an infant: responsibility of "maternalized" infant formulas].
[Article in French]
Couturier P, Basset-Sthème D, Navette N, Sainte-Laudy J
The case is presented here of a baby of 8 months fed from her birth with maternal milks. The first milk induced a severe gastro-intestinal disorder which disappeared when a second milk was used. A third milk caused a relapse. The only common allergen was coconut, which was physico-chemically modified in the second milk. Demonstration of the responsibility of coconut oil was based on positive re-introduction tests, positive skin tests for coconut and maternal milk that were negative for cow's milk and peanut and by specific IgE tests which were positive in comparison with negative controls.
Occupational allergic contact dermatitis due to coconut diethanolamide (cocamide DEA)
Volume 29, Issue 5, pages 262–265, November 1993
Coconut diethanolamide (CDFA). manufactured from coconut oil, is widely used as a surface-active agent in hand gels. hand-washing liquids, shampoos, and dish-washing liquids. CD HA has rarely caused allergic contact dermatitis. During NS5 IW2, we investigated 6 patients with occupational allergic contact dermatitis caused by CDEA. 2 became sensitized from a barrier cream, 3 from a hand-washing liquid, and 1 had been exposed both to a hand-washing liquid and to a metalworking fluid containing CDEA. Leave-on products (hand-protection foams) caused sensitization much more rapidly (2 3 months) than rinse-off products (hand-washing liquids: 5–7 years). Due to the extensive use of CDEA and the lack of proper declaration of products, it is difficult to avoid CDEA exposure. No contact allergy to another coconut-oil-derived sensitizer (cocamidopropyl betaine) was found in the patients.
Phil Lieberman, M.D.
I hope this information is of some help to you and your practice.
All my best.
Scott Sicherer, MD, FAAAAI
Dennis K. Ledford, MD, FAAAAI