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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
to
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
allergen.
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
allergic reaction.
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.
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
reaction.
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
reactions.
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
allergen.
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
reactions.
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
allergen.
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
system.
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
allergic reaction.
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
the
Epi-Pen, it should always be coming in a twin pack, because
you
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
reaction.
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
allergic reaction.
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
allergies.
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
of
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.