Photo Credit: 5second
In part 1, we explore a recent study that underscored the underdiagnosis and insufficient management of coconut allergies in the US.
There is significant underdiagnosis and suboptimal clinical management of coconut allergy in the US, according to study findings published online in Annals of Allergy, Asthma & Immunology. The study aimed to address the scarcity of epidemiologic data on coconut allergy in the United States despite labeling requirements. Conducted between October 2015 and September 2016, a research team led by Christopher Warren, PhD, and colleagues surveyed a nationally representative sample of US households to estimate the prevalence, severity, determinants, and distribution of coconut allergy.
From 78,851 respondents, 0.39% of the US population were categorized as having convincing coconut allergy. Children had a lower prevalence (0.22%) compared with adults (0.43%). However, only some cases (0.12% children, 0.20% adults) had physician-confirmed diagnoses. Notably, 40.1% of those with convincing coconut allergy had current epinephrine prescriptions, indicating the perceived severity of their condition. Furthermore, 47.5% of individuals with convincing coconut allergy reported reactions involving multiple organ systems, suggesting the complexity and severity of the allergic responses. Importantly, the data revealed that many individuals with symptoms consistent with an IgE-mediated allergy to coconut had comorbid food allergies, indicating potential complexity in diagnosis and management.
Despite the prevalence, a substantial portion of affected individuals lack formal medical confirmation, potentially impacting their ability to manage and treat their condition effectively.
Physician’s Weekly (PW) spoke with Dr. Warren to better understand why there is a need for improved awareness, diagnosis, and management strategies for coconut allergy to ensure the well-being of affected individuals.
PW: Can you explain the prevalence of coconut allergy in the United States?
Dr. Warren: Food allergies have long affected people, but there’s a widespread acknowledgment that in the last 20 years, the prevalence has increased quite a bit. The first major federal law passed to address the issue of providing information to consumers and everyone who buys food, which is all of us, about the presence of potentially allergenic compounds in those foods was done in 2004. Congress passed a bill called FPA—the Food Allergy Labeling and Consumer Protection Act—which took what was known at the time about the major allergens that were affecting people and codified it into a law that stated if you are a commercial entity making food and selling it in packages, there must be a label present of these specific food allergens.
These labels mirrored what they call the big eight food allergies—milk, eggs, fish, shellfish, tree nuts, peanut, wheat, and soybeans. However, they took a broad view of what they considered to be tree nuts because most of us think of them as nuts that grow on trees. They included coconut as a tree nut, which isn’t a tree nut, but Congress identified it as one, so there’s long been this question about whether it makes sense to regulate coconut as a tree nut given that it’s not actually a tree nut.
Another question we were trying to answer is the prevalence and burden of coconut allergy in the US because it’s a common allergy globally. We know many people are allergic to it, but there have been no efforts to because it’s not technically a tree nut. The studies that have tried to look at tree nut prevalence since 2004 haven’t looked at coconut. It was sitting as an allergy that many people acknowledge is important but is a big black box regarding who’s affected and how it burdens them.
We found that about one in 500 children had a coconut allergy as opposed to about two in 500 adults. And if you put that into percentages, it’s like 0.2% of children have a coconut allergy, and about 0.4% of adults have a coconut allergy. That is a lot of people when you multiply it by the hundreds of millions of people that live in the United States; it’s not as many as are affected by other tree nut allergies or are certainly other major allergies, but it’s about as many a little more than are affected by sesame allergy, which is one allergen that wasn’t included in that law in 2004 but was recently added as an additional allergy that allergen needs to be labeled in foods because it’s an allergen of increasing concern.
These data suggest we shouldn’t remove coconut from the list of important allergens.
What are the implications of the study results?
Coconut allergies appear to be increasing in prevalence, and one thing that we’re starting to understand more is the key role that the skin barrier plays in influencing the risk of developing subsequent food allergy. The dual exposure hypothesis says children with eczema or very early life skin barrier issues are at an increased risk of developing food allergies because skin becomes a barrier and keeps everything out. However, if your skin is chronically inflamed and letting in external pathogens and antigens, it creates a different route of exposure for your immune system. When your immune system is exposed to things like peanut dust or nut proteins through the skin instead of through the gut, which is how we evolved to first teach our immune systems about these things, it leads to inflammation, ultimately leading to allergy.
The use of coconut oil-based skin emollients and creams is on the rise—as is the consumption of coconut products everywhere. People are using coconut oil for their hair, coconut-containing products for their skin, and eating coconut in different capacities. Physicians need to be careful when dealing with unrefined coconut-containing products if they are recommended for babies to use on their skin because we think they will help improve their skin barrier. We also don’t want to deliberately expose babies to coconut protein through their skin, which might sensitize them and cause them to develop coconut allergy.
We haven’t been able to look closely at the effect and longer-term outcomes for all these kids now using coconut-containing creams and emollients. That’s something we as clinicians need to be attentive to. In our study, there’s a question about how much clinical testing you should do for food allergies when someone reports nonspecific symptoms that are potentially a food allergy. Because these tests have high false positive rates, the more food allergies you look for clinically, the more sensitization you often find. If that is not accompanied by a cautious evaluation of whether the kid or adult patient can safely consume that allergen without reacting, looking for more food allergies and preemptively excluding these things that the patient is sensitized to from their diet can often be counterproductive.
Overall, there’s not enough correlation between the positivity to different tree nuts and coconut. If someone you wouldn’t want to preemptively avoid coconut because of a tree nut allergy, for example, or because they’re sensitized to tree nuts just like any food allergy, physicians shouldn’t just suspect food allergy. A physician should take a meticulous history and ensure they are likely allergic to coconut before telling them.
Read part 2 here, in which PW continues the conversation with Dr. Warren about the underdiagnosis of coconut allergy among this patient population, and he provides strategies to improve access to emergency treatments.
