![[title]](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_scIr4v_unDVZNXy9w-EqXfcScvtqxK1BSkVaHz5Nira4hD9n3KG6wnE4GD9Lp2Fh-sP4Pp4G1hKDr0NgfGYlZvTWq_Rpw4aHN2wTrSGHzc=s0-d "[title]")
i'm nancy sanchez from our community health education programs. and, some of you i may have met at the past, at some of our other lectures. we do run this as a series of lectures throughout the school year. we have a handout in the back, and i can get some to you, if you haven't seen them yet. we have lectures in february next year, and again, in april.
we're doing eating disorders, and integrative medicine. all kinds of interesting things. and this evening, as you know, our most interesting lecture is going to be on pediatric food allergies. before i introduce our speaker i do want you to know that this presentation is being videotaped and will be posted on stanford itunes as well as on the hospital's website. so you can review, you don't need to take notes, you can
review everything. give us a couple of weeks to get everything posted, but it will all be up there to take a look at or to share with friends as well. so we're really pleased to have you here and look forward to your questions at the end of the presentation so that we are not also taping you in the presentation, we really want you to have privacy to ask some questions at the very end.
i am very pleased this evening to introduce to you dr. grace yu. we are very pleased to have her here. she is an adjunct professor here at stanford university school of medicine and her specialty, as you know, is in caring for children and adults with allergies and asthma. dr. yu's expertise includes all aspects of allergy, immunology, seasonal allergy, asthma, and atopic dermatitis. but her special passion is for food allergies and so we look forward to hearing her talk about dose research and oral
immuno-therapy and everything else that's new and exciting in the treatment of food allergies. she's won numerous awards in her field and including the patient choice award. so we're very pleased to have her here. she's well-published and well-researched, and you've got an expert here to share with you this evening. so we thank you, dr. yu for being here. and we thank you all for, coming to, enjoy our lecture this
evening. >> nancy, thank you for the kind introduction. and i apologize in advance. i'm a little bit sick this evening, so if i start coughing, please ignore that. in addition to my adjunct clinical faculty status at stanford, i'm also an allergist/immunologist at the palo alto medical foundation. and i'm very, very happy to talk to you today about food
allergies which nancy has mentioned, is a special passion of mine because i have family members with food allergies as well. so what i wanted to do was start out with a case presentation of a little child, and him getting born and what happened to him over time, in terms of allergies. so we're going to be covering a couple of additional topics, in addition to food allergies because of that. so, we're going to cover a little bit of atopic dermatitis,
asthma and then get to the heart of the presentation, which will be about food allergies and clinical research trials in that area. alright, so we're gonna start off with a little boy. this is a real little boy, his name is jacob. he was very healthy when he was born, and when he was four months old, he started to develop a red, itchy rash on his cheeks, his inner elbows and the back of his knees, which you
can see there. so he was diagnosed with atopic dermatitis, also known as eczema which is a very common skin condition that causes dry, itchy, easily irritated red skin. it affects one in six, people in the united states or approximately seventeen percent of the population. so it's very common and often presents, between two and six months of age. over 90 percent of children with atopic dermatitis have
symptoms before five years of age. and things that seem to make atopic dermatitis worse, are the scratching and rubbing that actually causes more inflammation of the skin, which sets up this vicious itch scratch cycle. infections such as colds rev up the immune system, but can also rev up the allergic part of the immune system, and cause the atopic dermatitis to get worse.
but 90% of children who have atopic dermatitis are colonized by a bacteria called staph aureus. and if they scratch their skin, the bacteria can then penetrate their skin and cause redness and infection and worsening of their skin. irritants such as like formaldehyde in new clothing can also irritate their skin. so we often tell families before you go ahead and apply
or give them new clothing to wear to go ahead and wash their clothes. and stress. hopefully little kids aren't too stressed, but as you get older, you start to become more stressed and that can definitely worsen their atopic dermatitis. dust mites are these little microscopic creatures which you cannot see with the naked eye, thank goodness. but you can see underneath a microscope and they live in the
pillow and the mattress and carpeting, etcetera, can also exacerbate atopic dermatitis. and about one-third of children of the moderate to severe atopic dermatitis have food allergies that make their atopic dermatitis worse. the key treatment for atopic dermatitis is skin hydration because their skin is dry and easily irritated, so you really want to get moisture back into their skin. so, the way that you do that is through the soak and seal
method, which works very, very well. you just give them a bath every day, lukewarm water. apply medicated ointments and then lock in the moisture with a good emollient like aquaphor, vaseline, or eucerin. and then, of course, medications are extremely important to control the inflammation, so topical steroids. one can also use topical immunomodulators like elidel or protopic. antibiotics are a key, are part of the
armamentarium for atopic dermatitis, things like keflex and bactrim. kids who have atopic dermatitis, some of them actually get better if they go to the swimming pool because that kills off the bacteria on their skin. so, we translated that into --- it's too cold right now to go swimming --- so they can actually go swimming at home in their bathtub
and you put a little bit of chlorox bleach in there and that can, for some kids, really improve their atopic dermatitis. because they have that vicious itch-scratch cycle at night, what you want to do is break that itch scratch cycle by giving them some antihistamines at night, like hydroxyzine. or during the day, you can give them some zyrtek to help with the, the inflammation. and then some kids with atopic dermatitis have a low vitamin
d level. vitamin d, actually, is very important in the synthesis of antimicrobial peptides on the skin. and so, if you can replete their vitamin d level, that can sometimes make their skin much better. this is a beautiful little girl who is actually in a bath tub. and she has wet wrap therapy on. which you can see she is floating, she looks like a little
angel there. and this was her before wet-wrap therapy and after wet-wrap therapy just after a week. so it can make a dramatic improvement in kids' skin just by hydrating their skin. it's amazing. and atopic dermatitis can definitely get better over time. so, does the risk of having atopic dermatitis increase your risk of developing other allergies?
and it is true that kids with atopic dermatitis are at higher risk of developing asthma, approximately 50 percent, and hay fever allergic rhinitis, approximately 75 percent as they get older. and it is important when you do have a child with atopic dermatitis to know that, because if the kid is coughing, and then subsequently wheezing, we know that they have a higher risk of asthma, so that we can properly treat them more quickly, and get them the right therapy, so that they don't
have any problems. with you know, inflammation or scarring of their lungs later on. so jacob got a little bit older and he caught a cold while he was in daycare. the cold progressed to severe coughing. he was breathing so hard that he was flaring his nose and sucking in all his chest muscles. and his parents brought him to the local emergency room. he was given a breathing treatment with albuterol.
but his cough and labored breathing, although improved, was still very, very worrisome. and so they actually life-flighted him to an intensive care unit at a local children's hospital for observation. so asthma affects more than six million children. and it's a very common chronic disease, where the airways of the lungs become sensitive to allergens and/or irritants. and when a person with asthma is exposed to these triggers, several things can happen.
so you can see, on the right hand side picture, that's a normal airway. it's nice and open and the little red bands around it are the muscles that surround the airways. when you have asthma, when they're exposed to irritants, what happens is the airway becomes very swollen. you can see the redness inside the lumen of the airway and then it can become, very, very tight. so, that the muscles, which are the red bands actually
constrict down and prevent, good air flow through the airway. typical symptoms of asthma are wheezing, persistent cough, especially at night, difficulty breathing or shortness of breath, chest tightness or discomfort, chest or sometimes the kids will actually refer down and say that their tummy hurts instead. they'll feel tired because they're having so much increased work of breathing they can feel out of breath and they may
or may not want to actually participate in any sports because they're so short of breath. signs that we look for when we look at children that have asthma are chest tightness, agitation, increased breathing rate and heart rate, inability to talk in sentences. instead they'll be like h-hi, h-how are you because they can' t breathe very well. they can have retractions where they use the chest, neck and
abdominal muscles to try and breathe. and they'll often refuse to lie down, they'll actually try and sit up and tripod to try and get better oxidization. and wheezing is just a whistle-like sound that is heard when air moves through airways that have become narrow cause it takes a lot more effort to pass air through narrow airways and that causes the feelings of shortness of breath and chest tightness. but the key thing is that not every child with asthma
wheezes, there is a type of asthma which is called cough variant asthma where they just cough, cough, and cough. and the reason for that is in order for one to hear wheezing, the airway actually has to be pretty small and you have to hear, you actually hear the turbulence which is what causes the wheezing but if the airway is still open but not quite open enough. the child will cough to try to stent
open or pop it to open the airway so that they can breathe easier. and typical triggers for an asthma attack are things like infections, like colds or a sinus infection, indoor and outdoor allergens like those dust mites that we saw earlier, cats as well as pollen, irritants such as cigarette smoke and paint fumes, exercise. some people even with strong emotions like laughing or crying,
it'll provoke them to start coughing. and then changes in temperature, such as exposure to cold air can trigger coughing as well. so the medicines that are used for asthma, they're the quick relief medicines and all those medicines do is just relax those red rubber bands around the airway or the muscles around the airway and they, can also be given ten to fifteen minutes prior to exercise if you have exercise-induced asthma.
and the typical asthma medications are things like albuterol, the brand names are proair, ventolin, etc. and then the preventative medications, the ones that target the inflammation are the anti-inflammatory medications. and you have to take those every day in order to prevent asthma symptoms. the typical examples of that are flovent, qvar, pulmicor, and singulair. oral steroids are often given in the setting of an acute
asthma attack and they're very potent anti-inflammatories that decrease mucus production but they do take several hours to start working. but they are essential in the management of an acute asthma attack. the typical examples of oral steroids for children are things like prednisolone, or orapred, pediapred, and prelone. and the goals of treatment for asthma are to prevent asthma
attacks, with the preventative medications and avoiding triggers, to know how to treat the asthma symptoms quickly and know when to get medical help. so we often use an asthma action plan where it's under the premise of a stop light where green is you're doing well, you take your preventative medications if you need them. yellow is when your asthma's getting worse and then there's a treatment plan for what to do when you're feeling worse.
and then red is a medical emergency and it goes over exactly what to do in the setting of a medical emergency. and we often work very closely with the parents, as well as the schools, to put together a good asthma action plan in place for the school, as well as with the school nurse to communicate so that they get great treatment at school too. cause the kids spend a lot of time in school. alright, and the long term outcome of children with asthma.
so there's this beautiful study that was done in australia, in melbourne. and it followed children out until they were 42 years old, so it's a very long-term study. so those kids with mild asthma, about 60% of them had no asthma in early adulthood, which is great. 10%, though, still had persistent asthma. for those kids who had moderate asthma, 60% had asthma in early adult life, and 30% of those just had mild symptoms.
and if they had severe asthma when they were children, about 80% went on to have moderate to severe asthma in adulthood. so resources are your doctor as well as your allergist and the allergy and asthma network, mothers of asthmatics, they' re a wonderful resource as well. so, now jacob's a little bit older. so at one year of age he ate eggs for the very first time and within just a few minutes of eating the first bite, he developed coughing and an itchy raised rash over his entire
body, which you can see here. so they brought him to the emergency room where he was given epinephrine and benadryl with subsequent resolution of his symptoms. his parents avoided giving him eggs again and brought him in to see an allergist and skin and blood allergy testing was positive to eggs. so now we're in the meat of the presentation now, talking
about food allergies. which i know is the reason you're here. so about four to six percent of children in the united states or four to six out of a hundred people, there probably almost a 100 people in this room, four to six, if this was a classroom, about four to six children here would have food allergies. it's the most common cause of visits by children, for severe allergic reactions, treated in us emergency rooms and even
with parents who are so vigilant for their children. they read labels and they do everything they can to try and prevent their child from having a food allergic reaction. even then, the statistics show that about fifteen to 50 percent of those food allergic children will have an accidental ingestion per year, on average. there is a voluntary registry that's maintained by the food allergy and anaphylaxis network and they estimate that about 100 to 150 deaths occur each year from food allergies.
but because it's a voluntary registry, it's probably an underestimate. nonetheless it's still is very rare given the prevalence of food allergies affecting millions of children, deaths from food allergies is still rare. so over 170 foods have been reported to cause allergic reactions. however, over 90% of food allergies are caused by the following foods: milk, egg, soy, wheat, nuts, fish, and
shellfish. so whenever i see a new patient in my clinic, i always ask about those foods because those foods are the most common to cause a food allergic reaction. this is a table that i really like. and what this goes over is, if you're allergic to one thing, what is the risk of reaction to at least one, of the other things in the second column? so, for instance, peanut is actually a legume.
so, what is the risk, if you're allergic to peanut, that you're going to have an allergic reaction to another legume, like a pea or a bean, ecetera. and it's only, thankfully, about five percent. if you're allergic to a tree nut, such as walnut, what's the likelihood that you're going to be allergic to another tree nut, like brazil nut, or cashew or hazelnut? it's about 37%. if you're allergic to one type of fish, such as salmon,
there's about a 50% chance that you're going to be allergic another type of fish, and so on. so the national institutes of allergy and infectious disease just released food allergy guidelines, which actually published on the web so you can look at it if you want to. there's one for patients and families, and there's one for medical professionals. don't read the one for medical professionals, cause that one
is over 100 pages long, and so i've decided just to summarize it all for you here. but they have a very clear definition for food allergy, which is "an adverse health event, excuse me, effect that arises from a specific immune response that occurs reproducibly on exposure to a given food." so, what are the typical signs and symptoms of a food allergic reaction.
and just to give you a little bit of background, the way i like to think about the allergic reaction is that. the immune system of a child who has developed food allergies has decided that, say for instance, that peanut allergen is an invader now, much like a virus. and we always fight off cold viruses by trying to get rid of it in our bodies. so it's the same idea with the food allergen.
so you can imagine if a child eats something that they're allergic to, that the body thinks of it as a foreign invader the body's gonna do everything it can to get rid of the food allergen. so, their eyes, they may start watering, or turning red or itchy. because the body is trying to flush out the allergen from their body, and trying to itch it out.
they may start coughing, in the hopes of coughing out the they may vomit if up, they may have diarrhea. they may have tummy pain, cause the body is trying to push out the allergen. if you actually listen to somebody who's having a food allergic reaction, you can hear that there's a lot of movement going on in their tummy cause the body's trying to get rid of the allergen.
the allergen is actually floating around in the blood, and so the body actually tries to get rid of it, by actually causing fluid to leak out of the blood vessel hoping that, that will also cause the food allergen to leave as well which leads to the swelling that one can see in a food so, i'm just gonna go through the list here. so, in terms of skin symptoms, you can just have fleshing. you don't actually have to have the mosquito bite hives,
that a lot of kids can get when they have a food allergic reaction. they can just feel itchy without actual rash developing on their skin, or they can have swelling, which we talked about earlier. their eyes can become red, itchy, and start tearing. their nose, the body's trying to get rid of the allergens so it's, you know, you're sneezing, your nose is
itchy in an effort to rub out the allergen. the nose can start running profusely. you know, the nose can become very congested in an effort to push out the allergen. even though it's obviously not coming in from the air, it's coming in by mouth, in most cases. it's trying to push it out in whatever way it can think of. the mouth can become tingly or itchy, and children
often say that the food is if they're not quite verbal enough they won't say my mouth is itchy. they'll say this is really spicy, or i don't like it, or they'll just spit it out. they can also get a metallic taste on their mouth, they can also develop swelling inside their mouth as well. their throat can become tingly or itchy. their throat can swell. we have had cases where children will start choking and
they'll grab at their throat. and their voice can change. they could become very hoarse because their voice box is being affected. it's, it's getting swollen. they can start coughing, they can wheeze, they can feel very short of breath, or have difficulty talking. or they can have the abdominal pain, nausea, vomiting, and diarrhea which we talked about.
and then, sort of the worst case scenario is the, you know the blood is leaking out of their vessels. they can have low blood pressure, dizziness, faintness. they can turn pale or they can turn blue and neurologically they can have headaches. they can have an impending sense of doom too. their body knows that something terribly wrong is happening to them and they can have anxiety. so children often have a unique way of describing their
experiences and perceptions which can often be very cute but in the setting of allergic reaction one has to be able to pick up on these unique ways of how they express themselves. precious time is lost when adults don't immediately recognize that a reaction is occurring. [sound] ... sorry for the interference here. i don't know if it's my hair,
get it out of the way. that's occurring, or they don't understand what a child's trying to tell them. and we've seen that on a couple of occasions. some children, especially very young ones, put their hands in their mouth, or pull or scratch with their tongues, in response to a reaction to try and, get the allergen out. also, children's voices may change, or become hoarse and squeaky.
or they can slur their words in the setting of an allergic so these are real life quotes from kids who are having food allergic reactions. "the food is too spicy." "my tongue is hot or burning." "it feels like something is poking my tongue." down here you can see, it, it says, "it feels like there are bugs in there." it just describes itchy ears, which is another symptom of food allergic reaction. "it feels like my throat feels sick.
" "it feels like there's a bump on the back of my tongue/ throat." so i'm often asked this question about severity of so their child has eaten, say eggs, for the first time and developed only hives, nothing else. so what's the chance that next time they eat eggs that it'll be any worse? maybe it will be
better, or maybe they won't have a reaction. so the severity of future reactions is gonna depend on a number of things. it's gonna depend on the state of the immune system, whether more allergy antibodies have developed which could lead to a more severe reaction. it also depends on how much they've ingested, too. so, say they ate say if a child's allergic to peanut, and they had just a
speck of peanut dust in whatever they ate and they only developed hives. well that's great, but if the next time they accidentally bite into a peanut butter jelly sandwich, the reaction could be more severe. so, i let all the families know that we can't know for sure what's going to happen the next time, but it's going to depend on a number of factors.
the other thing that can affect it is, whether the food is cooked or raw, so there's a very common phenomenon that we know about, called oral allergy syndrome. you may know people who when they bite into an apple, their mouth will become itchy. but if they eat an apple pie, they're totally fine. the cooked apple doesn't cause them to have any problems. so it's the raw apple, the protein in it that actually the immune system recognizes.
but the cooked apple, the protein, the 3-dimensional structure of the protein can actually degrade so that the immune system no longer recognizes it. it can also depend on co-ingestion of other foods. so if you have a child who's both milk and egg allergic, and they eat something that contains both milk and egg, the severity of the reaction, it can be much worse the next time. it can also depend on the rapidity of absorption, which is
based on whether food is taken on an empty stomach. if food is taken on an empty stomach, the food is more rapidly absorbed into the bloodstream. sometimes, if you exercise after you take your food now exercise is very good for people, it boosts the immune system, makes you healthy. but it can also boost, sort of, nonspecifically, your immune system. so we've definitely seen cases where, you know, they ingest
what they're allergic to. it's actually a described phenomenon, where, you ingest what you're allergic to. these people actually can ingest what they're allergic to, but be fine. but if they go out and exercise, they can develop anaphylaxis, or severe allergic reaction. and then, if they have other conditions, such as asthma. so if they do have asthma, and then they eat something that
they're allergic to, and their asthma was not well controlled to begin with, then they can have a lot of problems breathing, which can make the reaction worse. there is a phenomenon that's known as a bi-phasic reaction that can happen in the setting of a food allergic reaction. and it happens between about one to 20% of food allergic and it typically occurs eight hours after the initial reaction, but up to 72 and there's some been some reports
that are up to 78 hours after the initial reaction. and i've actually seen this in my own family members, who' ve, you know, 48 hours after a severe allergic reaction had another reaction. so the way i like to think about it, is when they eat something they're allergic to, alarms go off in the body saying, you know, there's something going on. there's a foreign invader. we've got to get rid of it.
so you have all the symptoms of an allergic reaction, but. at the same time it's signing off these alarm bells and doing all these so it's to try to get rid of the food it's also releasing chemical mediators throughout the body calling in the other allergy white blood cells and saying ok guys, come on over here. you know, we have a food allergic reaction going on.
so, it's calling in the cavalry, so that's why we get this biphasic or secondary reaction that can happen after the primary reaction. there are some suggestions that you know after a moderate to severe allergic reaction depending on the situation that it might be a good idea to monitor them for at least four to eight hours in the emergency room if they're already in the emergency room. and studies suggest that delayed administration, inadequate
dosing, or a need for large doses of epinephrine are risk factors for biphasic reactions. also failure to administer steroids also seems predisposed towards biphasic reactions as well. what are the risk of other allergies in a child who has food allergies? so about thirty five to seventy one percent, depending on the study that you read, also have con-committant atopic dermatitis like jacob did.
about thirty three to forty percent have allergic rhinitis which if we follow jacob out a little bit longer he also has allergic rhinitis. and about thirty four to thirty nine percent also have asthma as well. for the natural history is that most children will outgrow cow's milk, wheat, and egg allergies. far fewer though will outgrow peanut and tree, tree nut allergies.
and we'll go over the statistics in just a moment. a high initial specific allergy antibody or ige against the food is associated with a lower rate of resolution of clinical allergy over time. so, i am going to go through each of the foods individually now starting with cow's milk. it is the first foreign protein introduced to an infant's diet and it is the most common food allergy in young
children. about 2.5% of children have cow's milk allergy in the first two years of life, but only 1.1% of that is allergy antibody or ige meted. some kids if they drink cow's milk in infancy they will develop blood in their stools, but that's not ige meted, but we do consider it a cow's milk allergy. the minimal threshold that can trigger an allergic reaction in an exquisitely sensitive child is just drops of,
drops of milk. so one has to be very, very careful in an exquisitely allergic child. now there is, i get asked this question all the time. if my child's allergic to cow's milk, can they have goat's milk? and the answer is unfortunately, not. so there is a beautiful study that was done looking at the cross-reactivity between cow's milk, goat's milk, and
sheep's milk, and about ninety percent of all children who were allergic to cow's milk will be reactive on goat's milk, on oral food challenge, and that's because the proteins in cow's milk and goat's milk look very similar to the immune the good news is, is that 75% of cow's-milk allergic children will tolerate extensively heated cow's milk in baked goods, such as cakes and muffins, or waffles for example. so this is a beautiful study looking at the natural history
of cow's milk allergy that was coming out of johns hopkins, and what i just want to highlight for you is just over on the far left-hand corner that 88%, so by sixteen years of age approximately 88% of children will outgrow cow's milk allergy. in terms of hens egg, about 1-2% of children are allergic to eggs, and the yolk is considered less allergenic than the white. but i'm often asked the question, especially by asian
families who think the yolk is very nutritious, if my child is only allergic to the egg white, can i just give them the egg yolk? and unfortunately, it's very, very hard to only isolate the egg yolk because the white is just right next to it. so the safest thing to do is just to avoid eggs if your child is allergic to the egg white. the good news is that 70% of egg-allergic children, much like cow's milk allergic children, are also able to ingest
small amounts of egg protein that is extensively heated or baked in cakes, and muffins, and waffles again. and then again, another nice study from johns hopkins about the natural history of egg allergy. and again i'm just gonna point you all the way to the far right bottom hand corner showing you that by eighteen years of age, 95% of children outgrow their egg allergy. soy allergy effects less people, it's about 0.4% of children, and the natural history of soy allergy.
they have a little bit more limited data about soy, soy allergy cause it's not as common, but by about ten years of age about 69% of children outgrow a soy allergy. there is a nice diagram, and what i'm gonna, i'm just gonna walk you through this, so on the y axis is persistent soy allergy and on the x axis is the age of the child. and then the color bars, you can see that the orange colored
bar is if their initial soy ige level was 50 or higher at the time of their diagnosis. and then the blue bar is if their initial soy ige level was less than 4.9 at the time of their diagnosis. and you can see that the children whose ige levels to soy were 50 or higher were more likely to have persistent soy allergy by twelve years of age. about 40,
about 50 percent of them still had soy allergy. but the children who's specific ige level to soy was less than 4.9 in the blue bar that you can see there. about only 30% of them still had persistent soy allergy by eleven years of age. peanut affects about 1.1% of children, and it is the most common food allergy in the pediatric population beyond four years of age. so milk was the most common food allergy in less than four years of age and then peanut
overtakes milk by four years of age. it is the most severe food allergy and there are studies looking at the immune response to peanut allergy and we know that the immune response to peanut can be more potent. it actually activates different parts of the immune system, that are known to trigger more of the symptoms of an about a twenty one point five percent chance of outgrowing peanut allergy. even in the children who outgrow their peanut allergy.
there was a small study done at johns hopkins that. those children who passed their food challenge to peanut, when they outgrew it. the children who still hated the smell of peanut butter, and still actively avoided it, they had about a, they were more likely to actually have a recurrence of their peanut allergy, about 8% recurrence rate than those children who are, able to keep it in their diet and maintain their tolerance to peanut.
so we do recommend that if your child does outgrow a peanut allergy in that first year still carrying an epi-pen and then making sure that the peanut is actually regularly incorporated into their diet so that they maintain their tolerance to the peanut that they've outgrown. about 0.6% of the population is allergic to tree nuts. the most common tree nut that children are allergic to is walnuts, affecting about 34%. cashews about 20%, almonds 15% of kids, pecans about 9%,
pistachios 7%, and hazel nut, brazil nut, pine nut and macadamia nut, less than five percent. so when we do the testing, we do allergy skin testing. one's allergist or pediatrician may decide to do blood testing. these are complementary tests that we use, and sometimes we do one, we'll do the other, or we'll do both depending on the clinical situation. and the gold standard to determine whether your child truly
has a food allergy is a food challenge, but we often won't do a food challenge because the food challenge is often already happened at home which is why you're at the allergist's office, because you've given them that, you know bite of egg, and they've already had a life threatening allergic reaction, we don't necessarily want to repeat that because we don't want to put your child at risk. now this was published in the new york times a couple of years ago and it was talking about, sensitization to foods
versus clinical allergies to foods. so you can have food specific allergy antibodies in the blood but not have any allergies and i actually see this all the time. adults come in and they have stomach aches but they don't actually have a lot of the other symptoms of food allergic reaction and, sometimes blood work is ordered on them for a panel of foods and they get all these positives that come back but they're so confused because they're like but i eat
those foods and i am totally fine i don't have any symptoms and i say, that's great, just continue eating those foods. don't exclude that from your diet. we get lot of false positives on blood testing. no test is perfect unfortunately. so only 1/3rd of patients with positive testing actually had allergic reactions on food challenge and what we consider, that's called sensitivity if they have the presence of allergy antibodies either by skin testing or blood testing.
but what we are actually interested in is not whether they' ve been sensitized but whether they actually have clinical reactivity, so that's evidence of symptoms upon exposure to the food either by history or by food challenge. alright, so we do test high-risk children and we consider high-risk children siblings of kids that have peanut allergy, evidence of another food allergy, so a child has a milk allergy we'll often screen for other food allergies in that child,presence of atopic dermatitis, and a family
history of allergy. testing may be warranted as evaluation prior to introduction of a highly allergenic food, in an effort to prevent an allergic reaction from happening. however those who are not at high-risk, so if you and your spouse do not have allergies, allergies, and you have a beautiful, baby child. and they don't have eczema, and they're perfectly normal. we do not recommend testing or doing anything, anything
different than what you would normally do. you can go ahead and just give them foods like milk and eggs as you would normally would. so in terms of treatment for food allergies we recommend strict avoidance of allergenic foods. and i often send my patients over to a nutritionist, and the reason i do so, is for a couple of reasons. one is to educate them on how to read food labels.
so there was a beautiful study that was done showing that food allergic patients unfortunately incorrectly assume that terms such as "shared equipment," "shared facility," or "may contain" on the food labels indicate different levels of risk and they may or may not avoid products that say "may contain" or"manufactured on equipment." there was a study that was done, taking a look at all these
foods with those labels and about five to seventeen percent had a significant amount of food allergen in those foods. so it is risky, to continue giving those types of foods to your child, in the small chance that one could develop an allergic reaction and manufacturers are always changing the way things are made so you, you have to be vigilant even though your child may have eaten the same bread for years. and i can tell you with my own family experience. you just stop reading the labels because you know that bread
is fine, right? well, the next year they can change it and we have had cases where they change it without one knowing and a food allergic reaction can be induced. and the other thing that's really important is that the shared facility or shared equipment, it doesn't actually say that it is no different level of risk so if it says may contain versus shared equipment, nobody actually regulates exactly
how they term it. so it doesn't indicate any different level of risk and unfortunately 1.9 percent of reactions occurred in foods that didn't even declare that it had the food allergen and that typically happens with small manufacturers who just, you know didn't know any better, didn't realize, you know that their food was cross-contaminated with say milk or egg or wheat. the other reason i send families over to the nutritionist is
because one has to read both the ingredient list as well as the contain statement for the food labels. you can't just read one or the other. and then the last reason i send patients over to the nutritionist is because for instance, in milk allergy, we do know that milk allergic children can sometimes be a little bit smaller than children who don't have milk allergy. and they're not necessarily vitamin d deficient, but i always really wanna make sure, especially in a child who has
multiple food allergies, that they have nutritional adequacy of their diet. so this is just a pearl here. even when you ask about ingredient information, please know that you may not receive accurate information. the food allergy anaphylaxis network as you know has this registry and you know, people yeah, people will ask you know. this is a real life case, actually.
this teenager went to a food court and asked the person at the chinese stand, does the egg roll have peanuts in it, and the person said no, so the teenager bit into the egg roll and had a severe allergic reaction. and it's because they actually did have, they actually did put peanut, peanuts in the egg roll. they actually used peanut butter to actually seal the egg roll. so, if symptoms start, just assume an allergic reaction, and
call for help. and this little pearl that i have at the bottom is actually, from a colleague of mine whose daughter has peanut allergy. and he, you know, he worries, of course, about his daughter. cause she's now a teenager, and he has no control over what goes into her mouth anymore. so he only has one rule for her, which is "no epi,no eatie." so, she has to have the epinephrine with her when she eats because it is a lifesaving medication.
so epinephrine is first-line treatment as we talked about is lifesaving. unfortunately the majority of patients who have a prescription for epinephrine and this is more in the adult population, actually don't carry it. i know that for parents when your children have food allergies or much more like to carry it because you love your child but i think the adults are tend to not carry their epi pens quite as much and even those who carry their
epinephrine. don't always administer the medication when it's clinically indicated and the most common commonly cited reason for not using the epinephrine is, i just wanna see if the benadryl is gonna work first because i don't wanna give myself an injection or give my child an injection cuz i don' t wanna hurt them. and there was a study done out of mt.sinai that was published a while back showing that even when
prescribed epinephrine only about 21% of families knew how to use it correctly. so when you get the prescription for epi-pen, it should always be coming in a twin pack, because need that second one as a back-up and also you should have it because, up to 20% of allergic reactions require a second epi-pen in food allergic reactions. but you should also make sure that somebody shows you how to use it properly. and watch the video on the epi-pen.com website on how to use
it properly. and then, do a refresher every year, because if you don't have to use it, you've kept your child safe, it's very easy to forget how to use it. and i will sometimes have families practice on an orange too. so they know what it feels like for the real thing cuz the trainer is different than the real thing. the real thing is a spring loaded device so it.
the injection happens very, very quickly. it's actually a beautifully designed epi pen. i also want to talk to you about overcoming the fear of using epinephrine as well in the setting of food allergic i think almost everyone has a fear of using epi-pens, because it is an injection, and you never want to harm your child, you never want to inject them if not absolutely necessary. i had a mother tell me that she was at a school, and her
child has food allergies, and she was training the school nurse on how to use the epi- pen. and after she left, she was kind of in a rush so her heart was beating fast, and she noticed a little stain on her pant leg and she's like what's that? and then she realized she had actually injected herself while training the school nurse. and she had no idea that she did it, because it didn't hurt.
and i've been told, by a number of children, including my own family members that it doesn't hurt when they, use the epi-pen. i can't guarantee that of course, but i think the reason why for a lot of these cases it didn't hurt was because it is a spring loaded device and the needle goes in so quickly that before the brain can even register that the needle went in it's over and you didn't necessarily feel anything.
and then you feel so much better because you got the epi- pen, so now you can breathe again. you're not swelling, you're not coughing, ecetera. alright. so while administering the epinephrine call 911. and delayed administration of epinephrine has contributed to fatalities. so give the epinephrine immediately in the setting of a
moderate to severe allergic reaction. all other medications, including antihistamines like benadryl, or zyrtec or corticosteroids such as prednisolone, etc. are considered second-line treatment. and as we talked about benadryl or antihistamine use is the most commonly cited reason for not using the epi-pen. and may significantly the risk of a life threatening allergic reaction and a poor outcome.
as we talked about up to 20% of anaphylactic cases require a second epi-pen injection. and the antihistamines that we typically use are liquid zyrtec or liquid benadryl. benadryl comes as these pre- filled teaspoons which are very convenient to carry around. zyrtec actually is a generic called cetirizine, which you can get as a ten milligram chewable tablet for your older children, that is tutti-frutti flavored and you can get at safeway.
and it's very, very convenient to carry that around as well. but both those are fine. the, the one benefit of perhaps using zyrtec is that it has a longer duration of action, and perhaps less drowsiness associated with it. and the drowsiness can be confusing when you're treating allergic reaction because you don't know if they're becoming drowsy because you just gave them the benadryl or because they're having a blood pressure issue.
so sometimes we will use zyrtec in the setting of an the onset of action of zyrtec and benadryl are equivalent. and benadryl is what we consider a first generation antihistamine. zyrtec is what we call a second generation antihistamine that, that causes less side effects. so what is the role of antihistamines in the setting of an allergic reaction, and it is not lifesaving. it is only used to treat itching and hives in the setting of
an allergic reaction. it doesn't typically relieve any breathing problems, reverse low blood pressure, relieve abdominal pain. and the onset of action takes about fifteen to 30 minutes. with the caveat that liquid or chewable zyrtec or benadryl, if they're having itchy mouth, if you coat their mouth in the antihistamine oftentimes that will immediately alleviate their itchy mouth. i do strongly recommend having a food allergy action plan
which is downloadable at the food allergy and anaphylaxis network and it goes over exactly what to do in the setting of a food allergic reaction. so, i'll just go over this with you quickly. any severe symptoms after suspected or known ingestion and one or more of the following: any breathing problems, shortness of breath, wheezing or repetitive cough, any heart problems like paleness, blueness, weak pulse, dizziness or confusion, any throat symptoms like throat tightness,
hoarseness, trouble breathing or swallowing, any swelling of the tongue and/or lips or hives all over the body or a combination of symptoms from different body areas. so your child's vomiting and having hives or your child's having hives and tummy pain. then you want to go ahead and inject the epinephrine immediately and call 911 and then you can go ahead and give additional medications like the antihistamines or if your child has asthma and is coughing, you can give them the
inhaler. and then within ten to fifteen minutes if they're still having allergic reaction you can give them that second dose of epi, epinephrine. if they're only having mild symptoms, so a little bit of itchy mouth, a little bit of hives around their face or mouth, a little bit of itchiness of the skin, or just mild nausea or abdominal discomfort,
you can go ahead and give them the antihistamine. and just make sure to stay with them to make sure their symptoms don't escalate to needing epinephrine. and the back side of this is very useful for schools because it has all the emergency contact information for your family so that the teacher or the school nurse can contact you in the setting of an allergic reaction for your child. steroids have a theoretical rationale at preventing a biphasic reaction, or protracted reactions.
the one thing about steroids is that it doesn't work immediately though. so the onset of action is four to six hours. so often times we'll treat the allergic reaction with epi- pen and antihistamines, and inhalers if necessary. and then the last thing we'll do is give steroids, because we know it's not gonna work right away. and we just wanna prevent that biphasic reaction from happening.
and because that biphasic reaction can happen up to three days later, we give it for three days to try and prevent that. a medicalert bracelet is very important for a school age child. and you can get them from medicalert.org or laurens hope makes these beautiful medicalert bracelets. and what i like to have on the medic alert bracelet is what they're allergic to and, if somebody's looking for a
medicalert bracelet then you know that your child is in extremis. so i just have them put on the medicalert bracelet, give epipen and call 911 and then emergency contact information, like your cell phone number. the food allergy and anaphylaxis network is an amazing resource that sends out a newsletter every two months that updates families on the latest research trials, recipes, real-life stories.
and i have to be honest that, you know, i, i helped to do research in food allergies and every time i got the newsletter i learned something. whatever, you know, often times i learn from families which is really wonderful and so i know that if i'm learning something the families are definitely learning something so i, i always, always, always strongly recommend getting the newsletter and just signing up for it. and the website has great handouts, educational videos,
there's a little book series, and video series about alexander the elephant who has a peanut allergy and it's a great resource for kids to help them understand their food and then the food allergy and anaphalaxis network also sponsors walks to raise money for food allergy research and then you can see down here they have videos from other families whose children have food allergies and talking about their experiences which i think is very, very helpful.
their handouts are great. and i really like this particular handout, cuz it talks about, you know, you're not alone. avoidance is the only way to prevent an allergic reaction, outside of research trials, and always to have epinephrine available. so, future therapies. so there are studies right now on many different levels, for food allergies.
and i'm gonna go through each one of them. so, there's a study that looked at eating extensively heated products in children who could tolerate it. so children who are, again, cow's milk allergic, about 75% of them can tolerate baked milk products. and so what they did, was, they found out, which percentage could, and they actually had them ingest baked milk products every single day.
and about 60% of those that are eating, these baked milk products became tolerant, to unheated milk, like just regular cow's milk, compared to a control population, where only nine percent who reacted to baked milk products, could then tolerate unheated milk later on. this is a being followed up for three years, so it's a long term study which is very, very helpful. so subjects who could take baked milk products were sixteen times more likely to achieve tolerance compared to children
who could not tolerate baked milk products. so i do tell children who can tolerate baked milk products to continue to ingest those foods because my hope is that they'll be able to develop tolerance to unheated milk faster. there is a chinese herbal medicine that has been investigated in mice models of anaphylaxis. so this is a little mouse who's having anaphylaxis, actually.
so you can see the arrows, and where he, where the arrows are pointing are where he's actually swelling. so you can see swelling around his eyes. his paws are actually swelling, the back of his ears and the scruff of his neck are swelling. and in mice models this chinese herbal medicine, which is known as food allergy herbal formula two, can prevent peanut anaphylaxis in these susceptible mice. so they're now doing clinical trials in humans.
there's been a lot of research which has been done for a long time looking at engineered or recombinant peanut protein. so one of the major peanut proteins that is implicated in peanut allergies is ara h1. and so, this is the key dimensional structure of ara h1. and what they've done is they've found the portions of the protein where the ige or allergy antibody binds to, and they'
ve done sight directed mutagenesis. they've actually altered the places where they bind in the hopes of trying to create a vaccine for peanut allergy. anti-ige therapy has been studied in a number of trials. and in the most recent trial that was published about eight out of nine patients who were on the active treatment arm had an increased threshold of reactivating to peanut. so before, for instance they could only tolerate one fifth of a peanut and they'd have allergic reaction and, while on
anti-ige therapy some of them could eat like the equivalent sixteen peanuts while being on anti-ige therapy. unfortunately, that, most recent study was stopped prematurely. because in order to enroll in these studies, we have to do food challenges to confirm that the person's actually allergic to what they say they're allergic to. because these studies, are, can be long, and we don't wanna waste anybody's time if it turns out that
one's child has outgrown the allergy, for instance. so, unfortunately, this trial was stopped, because during the qualifying oral food challenges, the severity of anaphylaxis, made it so that the trial had to stop. there are studies i'm looking at, peanut patches and milk patches applied to the skin in an effort to desensitize children to those foods. and the way i like to think about the desensitization process is, if i hit your knee really hard.
you would be very annoyed by me. and you would wanna swat my hand away. but if instead i went ahead and just tapped your knee very, very gently, for days to weeks to months to years on end, you would eventually ignore my tapping. and so that's what we're trying to achieve in the desensitization process, is we're gently tapping the immune system, saying "you're not allergic to the peanut. you're not allergic.
[laugh] stop trying to swat it away. you can do it. you can overcome this. so in a small pilot study with a milk patch, they did find an increased threshold of being able to tolerate milk, so, they're expanding those studies. so in food oral immunotherapy what we've done is, we take a almost, an almost microscopic amount of peanut flour or milk flour.
i mean, literally it's so tiny that if you breathe on it, it blows away. and we give it to a child and gradually increase the dose over a long period of time in an effort to desensitize them. and we have had children who have been able to graduate from the study who previously had for instance life-threatening allergic reactions to peanut and are now eating the equivalent of sixteen peanuts a day, which is pretty extraordinary.
so one can do it either by doing it in a flour form which is what we do at stanford and we put them in these little souffle cups. you can see a little girl getting ready to take her dose with food. our colleagues are doing it as well in a dropper format. this is actually peanut extract which you'd actually put underneath the tongue and desensitize them that way as well, and that shows promising results too.
so the success rate, after three years of treatment 93% of children, or 27 out of 29 children who were allergic to peanuts became desensitized in a trial at duke. and 48% of those became tolerant to peanuts. and what we mean by tolerant is they had been taking their maintenance dose of peanut every day. and then they came off of peanut altogether for three months. and then they had another oral food challenge to peanut.
and whether they passed the oral food challenge or not helped us to determine whether or not they became tolerant. and three months isn't very long, of course. so we think of it more like short-term tolerance so about a 50% short term tolerance or hopeful cure for those kids. and the only thing that seems to predict whether or not those kids pass the end of study food challenges are initial specific ige level to peanut at the time of entry. so, our current research we have a third of children who are
allergic to more than one food and so although it may be fantastic and life-changing to be desensitized to peanut, unfortunately as you know, when you have a peanut allergy there is a risk of you also being allergic to tree nuts. so, it still puts a damper on things when you're still avoiding tree nuts, for instance. so, what we've tried to do is to desensitize multiple foods at the same time. so milk, egg, peanut, tree nut, etc. there was also a study
that was recently published by our group where we combined anti-ige therapy with, with milk oral immunotherapy, or milk desensitization. and that seemed to allow for a faster desensitization, cuz these studies take a long time. because we're just so gradually and carefully desensitizing children with these very tiny amounts of peanut or milk, over long periods of time. so, this is just a newsletter that i'm putting together.
keeping people updated about, food allergies, and research that's being done in the bay area. but i'm happy to take your questions, now. and thank you very much for your time. clapping.