Update on Food
Allergy
and Asthma
JASON FRIESEN MD
OREGON ALLERGY ASSOCIATES
OAK STREET MEDICAL
Prevalence of Food Allergies in
the United States
Food
Young Children Adults
Milk
2.5%
0.3%
Egg
1.3%
0.2%
Peanut
0.8% (~2%)
0.6%
Tree Nuts
0.2%
0.5%
Fish
0.1%
0.4%
Shellfish
0.1%
2.0%
Overall
6% (~8%)
3.7%
Sampson HA, Update on food allergy. J Allergy Clin Immunol 2004;113:805-19
Perceived prevalence of
Food Allergy

A whole population birth cohort was established
on the Isle of Wight.

Parents reported food hypersensitivity in 25.8% of
their children.

The actual incidence of food hypersensitivity
confirmed by open food challenge or DBPCFC at
one year was 4.0%.
Venter C, Pereira B, Grundy J, Clayton CB, Roberts G, Higgins B, et al. Incidence of parentally reported and
clinically diagnosed food hypersensitivity in the first year of life. J Allergy Clin Immunol 2006;117:1118-24.
Presenting Symptoms by Percent of
Occurrence in Pediatric Anaphylactic
Patients
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
Cutaneous (n=57)
Resp (n=38)
Cardio (n=28)
Laryngeal (n=25)
GI (n=22)
Allergy vs. Intolerance
IgE Mediated (allergy)
Non-IgE Mediated
(intolerance)
Classic symptom
Cutaneous (hives,
flushing, swelling)
GI (bloating, gas,
nausea, diarrhea)
Speed
Minutes to hours
(unlikely >4 hrs)
Hours to most of a day
Frequency
Every time the food is
ingested
Sporadic
Dose Dependency
Appears non-dose
dependent
Appears very dose
dependent
Casual contact with peanut




Thirty highly allergic children underwent the
challenges.
None experienced a systemic or respiratory
reaction. Erythema (3 subjects), pruritus without
erythema (5 subjects), and wheal-and-flare
reactions (2 subjects) developed only at the site
of skin contact with peanut butter.
“From this number of participants, it can stated
with 96% confidence that at least 90% of highly
sensitive children with peanut allergy would not
experience a systemic-respiratory reaction from
casual exposure to peanut butter.”
J Allergy Clin Immunol. 2003 Jul;112(1):180-2.
Airborne peanut exposure

Participants consumed peanuts in various
forms to simulate situations that might create
airborne peanut allergen.
 To simulate a school cafeteria setting,
participants consumed peanut butter
sandwiches.
 For environments similar to sporting events,
participants shelled and consumed
roasted peanuts. Participants were
encouraged to discard peanut shells on
the floor and were also allowed to walk on
the shells during many of the sessions.
 To simulate the environment on
commercial airliners, each participant
opened 15 bags of unshelled peanuts in
small, ½-oz packages and consumed the
nuts.
J Allergy Clin Immunol 2004;113:973-6.
Airborne peanut exposure
J Allergy Clin Immunol 2004;113:973-6.
Severe and fatal reactions
Fear vs. dread

“Social scientists have known for a long time
that there are dangers whose risks we
underestimate, and there are dangers whose
risks we overestimate. They talk about the
difference between things that we fear and
things that we dread.
“We fear cancer and heart disease and
traffic crashes, but psychopaths and serial
killers and airplane crashes are things that we
dread. So when a danger seems like it's
inexplicable, when we have absolutely no
control over it, when suddenly, out of the
blue, it causes mass casualties, this causes
not fear, but dread. And when it comes to
dread, that's when we tend to overestimate
the risks.”
Incidence of fatal food
reactions

In food-allergic people, fatal food anaphylaxis
has an incidence rate of 1.81 per million personyears (95%CI 0.94, 3.45; range 0.63, 6.68). In
sensitivity analysis with different estimated food
allergy prevalence, the incidence varied from
1.35 to 2.71 per million person-years. At age 0–19,
the incidence rate is 3.25 (1.73, 6.10; range 0.94,
15.75; sensitivity analysis 1.18–6.13).
Putting it in perspective

Shark attack: 0.1 per million person years

Death by lightning: 0.22 per million person years

Fatal anaphylaxis: 1-3 per million person years (in
allergic persons)

Fatal influenza: 100 per million person years (in the
US)

Using envelope math we can expect a food
allergy death in a child every 7-20 years.
Risk for Fatal Food
Reaction
Large majority of victims were adolescents or
young adults
 A prior history of allergy to the specific food is
very common.
 Asthma appears to be a strong risk factor.
 Epinephrine needs to be given in a timely
manner.



From Sampson’s original 13 cases: “The six
patients who died had symptoms within 3 to 30
minutes of the ingestion of the allergen, but only
two received epinephrine in the first hour. All the
patients who survived had symptoms within 5
minutes of allergen ingestion, and all but one
received epinephrine within 30 minutes.”
Peanut and tree nut caused 95% of fatalities.
Fatal and near-fatal anaphylactic reactions to food in children and adolescents.
Sampson HA - N Engl J Med - 6-AUG-1992; 327(6): 380-4
Epinephrine




Epinephrine is safe in children.
It may cause pharmacologic adverse
effects such as anxiety, fear,
restlessness, headache, dizziness,
palpitations, pallor, and tremor.
Rarely, and especially after overdose,
it may lead to ventricular arrhythmias,
angina, myocardial infarction,
pulmonary edema, sudden sharp
increase in blood pressure, and
intracranial hemorrhage.
There is, however, no absolute
contraindication to epinephrine use in
anaphylaxis.
F. Estelle R. Simons, J Allergy Clin Immunol 2004;113:837-44.)
Epinephrine

EpiPen Jr 0.15mg is optimally dosed for a 15kg
child (50%ile 3 years old).

EpiPen 0.30mg is optimally dosed for a 30kg child
(50%ile 12 years old).

Personally I switch up at 20 kg (45 pounds) (50%ile
6 years old).

The 5/8” length may be too short to ensure
intramuscular injection of epinephrine in obese
individuals.
Practical tips about food
allergy action plans

Low threshold for giving epinephrine:


Pros:

Early administration for life threatening cases.

Low risk of significant side effects in children

Simpler decision making for non-medical personnel

Decreased liability?
Cons:

Potential cost with ER/ambulance

Psychological burden of increased fear

High threshold for giving epinephrine:


Pros:

Decreased inappropriate uses of epinephrine

Less “knee jerk”

Cost savings of used epi-pen
Cons:

Increased risk of delayed epi in life threatening case

More decision making required

Increased liability?
The LEAP
study
SHOULD IT HAVE BEEN CALLED THE “TURN THE
WORLD UPSIDE DOWN STUDY”?
LEAP study

Current guidelines recommended avoiding
allergenic foods such as peanut or shellfish until
age three for siblings of allergic patients.

Is this the right advice?

In the UK women were adviced to avoid eating
peanuts while pregnant and avoid giving peanuts
to children until three yet the incidence of peanut
allergy continued to climb.

Jewish mothers in the UK were more likely to have
peanut allergic kids than Jewish mothers in Israel.
One difference was kids in Israel have early
exposure to peanut.
LEAP study
LEAP Study

640 infants between 4 and 11 months randomized
to eat at least 6g peanut protein per week.

All had eczema, egg allergy or both.

Stratified between negative skin prick and positive
skin prick.
LEAP Study


530 infants had negative skin prick result.

13.7% of avoidance group developed peanut
allergy.

1.9% of consumption group developed peanut
allergy. (86% risk reduction)
98 infants had positive skin prick results.

35.3% in avoidance group

10.6% in consumption group (70% risk reduction)
Siblings of peanut allergic
children

Prick test early

If negative, introduce peanut


Practical issues with keeping peanut in house to
feed sibling while keeping it away from allergic
child.
If positive, consider challenge in office or
avoidance.
Oral immunotherapy
•
The primary outcome, desensitisation, was recorded for
62% in the active group and none of the control group
after six months. 84% of the active group tolerated daily
ingestion of 800 mg protein (equivalent to roughly five
peanuts).

Happening in Oregon

Tolerance vs. Desensitization?


“bite proof”
Cost and coverage
Asthma
The September epidemic of asthma hospitalizations: School
children as disease vectors
Neil W Johnston, MSc, Sebastian L. Johnston, MD, PhD, Geoff R. Norman, PhD, Jennifer Dai,
MSc, and Malcolm R. Sears, MB, ChB
Hospital admissions for
asthma in 5 to 15 year olds
Neil W. Johnston, J ALLERGY CLIN IMMUNOL; 117 (3); 557
Other Studies find the same
thing

This effect has been noted across the northern
hemisphere:


Finland, Canada, United Kingdoms, United States,
Mexico, Israel, Trinidad.
A parallel post-summer vacation effect has been
noted in the southern hemisphere as well:

South Africa, Australia, New Zealand
Noncompliance?

Summer tends to have the fewest asthma
admissions.

Schedules for school kids are much more chaotic
making routines harder to keep.
Noncompliance
Neil W. Johnston, J ALLERGY CLIN IMMUNOL; 115 (1); 137
Hospitalizations by age in
relation to Labor Day
Neil W. Johnston, J ALLERGY CLIN IMMUNOL; 117 (3); 557
Short-Course Montelukast for Intermittent Asthma in Children
A Randomized Controlled Trial
Colin F. Robertson, David Price, Richard Henry, Craig Mellis, Nicholas Glasgow,
Dominic Fitzgerald, Amanda J. Lee, Jane Turner, and Melissa Sant
Methods

Double-blind, randomized, placebo-controlled
trial comparing 7-20 days of montelukast at the
first sign of a URI.

220 children age 2-14 randomized.
Results
Colin F Robertson, AMER JOUR RESP CRIT CARE, 175; 323
Results, cont.
Colin F Robertson, AMER JOUR RESP CRIT CARE, 175; 323
Conclusion

“For 100 patient episodes treated with
montelukast, there would be an avoidance of
one hospital admission, six emergency room
attendances, two specialist consultations, and
eight GP visits.”
Quadrupling the Dose of
Inhaled Corticosteroid to
Prevent Asthma
Exacerbations: A
Randomized, Double-blind,
Placebo-controlled,
Parallel-group Clinical Trial
Janet Oborne, Kevin Mortimer,
Richard B. Hubbard, Anne E
Tattersfield, and Tim W
Harrison.
University of Nottingham, Nottingham,
United Kingdom
J Obonre, Am J Respir Crit Care Med Vol 180. pp 598–602, 2009
Results cont.

“Among the 94 participants who started the study
inhaler, quadrupling the dose of inhaled
corticosteroid led to a marked reduction in the
need for oral corticosteroids (21 vs. 50%, relative
risk reduction, 57%).”

Practical consideration: Running through a
month’s worth of ICS in one week. Cost and
insurance headache.
Conclusions

September asthma

A real event

Occurs roughly three weeks after Labor Day.

Likely virally driven, although summer noncompliance may play a factor.

Having kids on their controller before Labor Day
may be beneficial to avoiding an exacerbation.
Asthma Phenotypes
Not all kids respond the
same
Stanley J Szefler, JOUR ALLER CLIN IMMUN, 115 (2); 233
Conclusions

Phenotypes of asthma

An exciting horizon of research

Different phenotypes may respond to different
modalities of medical therapy.

FeNO can help reveal kids who will most likely
respond to inhaled steroids.
Step-up Therapy
Exercise asthma
Differential Diagnosis
Exercise
Asthma
VCD
Conditioning
Symptoms
SOB, cough, SOB, cough,
wheeze (exp) “wheeze”
(insp)
SOB
Timing
Prolonged,
worsening
after
stopping
Short,
improves
when
stopped
Short,
improves
when
stopped
Location
Chest
Throat /
upper chest
Diffuse
Treatment
Albuterol
Breathing
exercises
Exercise
Using your inhaler
Using an inhaler (with
spacer)

Shake well for 5-10 seconds.

Insert the MDI into the open end of the chamber.

Breathe out all the way.

Keep your chin up.

Place the mouthpiece of the chamber between your
teeth and seal your lips tightly around it.

Press the canister once.

Breathe in slowly through your mouth to completely fill your
lungs. If you hear a "horn-like" sound, you are breathing too
quickly and need to slow down.

Hold your breath for 10 seconds (count to 10 slowly) to
allow the medication to reach the airways of the lung.

Wait about 1 minute in between puffs.
No spacer
1.Shake well for 5-10 seconds.
2.Breathe out all the way.
3.Keep your chin up.
4.Place the mouthpiece of the inhaler
between your teeth and seal
your lips tightly around it.
5.As you start to breathe in slowly, press down on the canister one
time.
6.Keep breathing in slowly to completely fill your lungs. (It should
take about 5 to 7 seconds for you to completely breathe in.)
7.Hold your breath for 10 seconds (count to 10 slowly) to allow the
medication to reach the airways of the lung.
8.Wait about 1 minute between puffs.
9.Replace the cap on the MDI when finished.
New Therapies


Biologics

Xolair

Mepolizumab
Generic Advair
Jason Friesen MD
Email: jason@oregonallergy.net
Phone: 541-683-1577 (main)
541-431-9422 (direct)