FOOD ALLERGIES ON THE RISE IN AMERICAN CHILDREN
You are listening to ReachMD, The Channel for Medical Professionals. Welcome to Hot Topics in Allergy, presented by the American College of Allergy, Asthma, and Immunology. Your host is Dr. Ketan Sheth, Medical Director of the Lafayette Allergy and Asthma Clinic in Lafayette Indiana.
Food allergies in American children has increased in the last decade. According to the CDC, 3 million children have food allergies and hospitalizations have increased fourfold in the last decade. Why are food allergies becoming more prevalent? Joining us to discuss food allergies on the rise in American Children is Ms. Amy Branum. Ms Branum is from the Centers for Disease Control and Preventions, National Center for Health Statistics, Office of Analysis and Epidemiology, Infant, Child, and Women's Health Statistics branch.
DR. KETAN SHETH:
Welcome Ms. Branum.
MS. AMY BRANUM:
Thank you I am happy to be here.
DR. KETAN SHETH:
Well how much has the food allergies increased in this study?
MS. AMY BRANUM:
So over the time periods we looked at from 1997 through 2007, we found an increase of about 18%.
DR. KETAN SHETH:
Well 18%, that is a significant statistic. How would you define food allergies?
Ms. AMY BRANUM:
Food allergies and the data that we had available to us were defined as any reported food or digestive allergy in the child in the previous 12 months. So I should note that these data are based on reported food allergy a parent or proxy.
DR. KETAN SHETH:
So whether it was confirmed by a physician or it's more if the parents thought the child had a food allergy?
MS. AMY BRANUM:
Right, so unfortunately we don’t have diagnostic confirmation on these reports; however, it should be noted that we have another survey, this National Survey of Children's Health that was done in 2003 which asked about a doctor diagnosis, still not ideal, but at least it asked about a doctor diagnosis versus a parent or proxy, their own ideas of whether or not their child might have food allergy and we found very similar estimates. Whether it was a doctor diagnosis or parental report.
DR. KETAN SHETH:
Can you explain some of the reasons that you found for this increase?
MS. AMY BRANUM:
Well again our data don’t allow us to really examine changes in exposures for example and obviously these are not longitudinal data, so of course we can't follow the same children over time; however, it certainly the case that food allergy awareness has increased quite a bit in recent years and I think that is due to a combination of media, information and increases in the media and awareness in parents and awareness in the schools. So it is possible what we are seeing here is an increase in awareness by parents perhaps they are getting their children diagnosed more frequently or taking them into the doctor when they do think there are signs and symptoms of a food allergy. In addition, it seems like we are hearing increased cases in the school setting as well, so my suspicion is this may be some combination of increase in awareness and increase in true illness if you will.
DR. KETAN SHETH:
What was the severity of some of these allergies in these children under 18?
MS. AMY BRANUM:
Well unfortunately our data won't allow us to examine that as well. So I should state that the data are fairly general that these come from the strength is that they allow us to make nationally representative estimates of children with reported food allergy. However, other than the question about food allergy itself, we really don’t know much about the experiences of these children. So for example we don’t know what types of foods they are allergic to or how severe their symptoms are.
DR. KETAN SHETH:
One of the things I had mentioned at beginning was that hospitalizations went up fourfold, does that you think link with the increased numbers or is it more severe in what's going on or are we under treating it. How does that number fit with all of this?
MS. AMY BRANUM:
Sure, so I think again it could be a combination of things happening. One thing we noted was we looked at all hospitalizations or I should say hospitalizations that had any diagnosis related to food allergy. So it did not have to be the primary diagnosis. It could have been any of the 7 that are listed in the records for the national hospital discharge survey from which these data come from and what we found was when V codes were introduced, I believe they were introduced around 2000. These are codes that are in addition to sort of the standard ICD-9 codes that are used to diagnose the condition for which the patient came into the hospital for. V-codes are used to identify condition that may be of importance when somebody comes into the hospital for whatever reason and what we found were a lot of these increases were due to increasing use of V-codes and that could certainly get back to the increases in prevalence. So children might not be coming into the hospital primarily because of the food allergy, but they, more children may have food allergy and that may be showing up in the V-codes for these diagnoses.
DR. KETAN SHETH:
It is not a glum as we look at the hospitalizations, it may just be the prevalence that is higher, that is why we are seeing more people. We are not having more severe reactions or you really can't sort that our from the data.
MS. AMY BRANUM:
My impression from the data when we looked at it was that it is not necessarily due to increases in primary diagnosis which is the good news. The good news is that we are not seeing a lot more hospitalizations due to more severity in disease; probably I think we might be looking at more increases due to prevalence.
DR. KETAN SHETH:
Did you find other health concerns linked to these kids who had food allergies?
MS. AMY BRANUM:
Yes, so one thing the National Health Interview Survey did allow us to examine was coexisting conditions with food allergy and this is important because I don’t think this data have been shown this way on a national level prior to this report and what we found were conditions such as asthma and skin allergy or eczema and other respiratory allergies were 2 to 4 times higher in these kids with food allergies compared to children without food allergies.
DR. KETAN SHETH:
Why do you think some of that is?
MS. AMY BRANUM:
Well this corroborates what's in the clinical literature from what I have seen that these children often these coexisting allergic conditions and we also know from the clinical literature that children who have food allergies as young children or infants even though most of them will outgrow those food allergies. Unfortunately they may go on to develop other allergies such as respiratory or seasonal allergies. So I think it just gives a better picture on a national level for how many of these kids have these coexisting allergic conditions. In addition, there is some evidence that children who have food allergy and asthma may be at risk for more severe reactions both as children and then later on in adulthood if they do not outgrow their food allergy and have coexisting asthma. So this could be potentially important for that subset of people with food allergy and asthma.
DR. KETAN SHETH:
Should practitioners out there who see somebody with a food allergy or perhaps even parents who may be listening who have somebody with a food allergy, should they get their children evaluated for asthma or other allergies?
MS. AMY BRANUM:
It certainly would not hurt. I am not a doctor; I am not a medical doctor. So I certainly could not attest to clinical practice, but it does seem like what we are seeing in the national data show very good evidence for high rates of co-occurrence in these conditions. So if the parent knows, the child has a food allergy, it has already been previously diagnosed, it certainly would be worse watching the child for signs and symptoms of other allergies and then getting them tested as needed.
DR. KETAN SHETH:
In essence it is a great reminder that what you had mentioned earlier that there is certainly a link and an association between the people who have food allergies may be going on to get asthma and other respiratory allergies and I think great awareness to make sure that we all know that and patients are out there trying to get this looked at. What are some of the food groups that were the most common allergens?
MS. AMY BRANUM:
Well again in The National Health Interview Survey, we could not look at specific food groups. We do know from other data that only about 8 types of food make up the majority of food allergies and those include the common foods that we hear most about such as peanuts, tree nuts, and fish. Other items like soy and wheat and shellfish make up the majority of the food allergies among children and adults with food allergies.
DR. KETAN SHETH:
So in this survey were you able to specifically sort our which food allergies they had or it was more whether they had them or not?
MS. AMY BRANUM:
It was just whether they had them or not. We have another survey, The National Health and Nutrition Examination Survey that is a more clinical survey. It is more inclusive of different clinical factors and they actually did serum IgE levels for I believe it was 4 different types of food and those data have not been released yet, but we do plan on looking at those. So at least we could get some sense of the prevalence of IgE mediated food allergies to a few specific foods and those do include peanut and milk I believe.
DR. KETAN SHETH:
If you are just tuning in, you are listening to Hot Topics in Allergy on ReachMD, The Channel for Medical Professionals. I am your host, Dr. Ketan Sheth and joining me today to discuss food allergies on the rise in American children is Ms. Amy Branum from the Centers for Disease Control and Prevention, National Center for Health Statistics, Office of Analysis in Epidemiology, Infant, Child, and Women's Health statistics branch.
As you look at some this data Ms. Branum, is this data very similar to that of other countries?
MS. AMY BRANUM:
Well it is hard to make prevalence estimate comparisons just due to the different numbers of children obviously and I also have not seen many studies that have had national prevalence estimates from other countries. So again it is hard to make comparisons. Now one that I have seen in the literature, in the epidemiologic literature is increases in specific food allergies, like peanut allergies. So for example, there have been some studies from the UK that have demonstrated increased in peanut allergy and those were based on population based studies. So the numbers aren’t quite as large and representative as we might like, but I think they were large enough to capture a fairly robust increase in food allergy.
DR. KETAN SHETH:
Are there other countries where peanut allergies are decreasing or as not as much of a problem as they are in the US?
MS. AMY BRANUM:
So there is some evidence again in the clinical or medical literature, that there are countries that do not appear to be having the same rate of peanut allergy per se and I believe one of those countries that have been mentioned include Israel for example and one thing I have seen is that children in Israel are exposed to peanut products at a younger age. It is like, I am not sure if it is a candy, but it is some type of product that has peanuts in it and they are exposed to those things at a very early age. I am assuming they are quite prevalent and they do not appear to have the same rates of peanut allergy as children in other countries. So that is just one example and again it is kind of an ecologic example. So we don’t know for sure if that food item is what's really giving these children some kind of protection or if there is something else in their environment that might be protecting them. It is an interesting case.
DR. KETAN SHETH:
That is a very interesting situation because; certainly clinically it is recommended not to introduce peanuts for a number of years here in the US at least by the American Academy of Pediatrics to at least 2 or 3 years depending what you are eating. So that is very interesting and suggests maybe we need more of these types of studies to figure out where they are coming from.
MS. AMY BRANUM:
Right and there is also some evidence that the way the peanuts are cooked, you know, could have some influence on that as well. For example, we have a lot of roasted, high-roasted, high-heat roasted peanuts in America. That is how they are most commonly consumed and so there could be some differences based on how they are prepared which could offer some protection.
DR. KETAN SHETH:
Is there anything in the data that you looked at that suggests some of these children will outgrow their allergies as they get older and mature?
MS. AMY BRANUM:
Well what we know from the medical literature is that most of these children will outgrow, particularly the sort of milk and egg type allergies that they may have as young children and I think what is really missing in the medical literature is what types of children do and do not outgrow these food allergies and what is it about them that sort of characterizes whether or not they will outgrow these allergies. I think obviously parents would love to know that kind of information and unfortunately I think you alluded to previously, we just haven’t had the right kind of studies or the ability to really examine the differences in these children and follow them over a long period of time to determine why some children will outgrow these food allergies and some will not.
DR. KETAN SHETH:
What about adults, are they becoming a greater concern to food allergies in adults in addition to this dramatic increase in kids?
MS. AMY BRANUM:
Well that’s a great question and I think, you know we were so concerned with focusing on the children for this first report; we haven’t even looked at the adults. We certainly do have information for adults in the same survey and it is something we plan on looking at in the future.
DR. KETAN SHETH:
I would like to thank my guest from the Centers for Disease Control and Prevention, Ms. Amy Branum. Ms. Branum thank you very much for being our guest this week on Hot Topics in Allergy.
MS. AMY BRANUM:
Thank you.
You have been listening to Hot Topics in Allergy. This show has been presented by the American College of Allergy, Asthma, and Immunology. For more information on the ACAAI, please visit www.acaai.org. For more information about this or any other show, please visit www.reachmd.com which now features on-demand pod casts. Thank you for listening.