Are the dangers of childhood food allergy exaggerated?
BMJ 2006; 333 doi: https://doi.org/10.1136/bmj.333.7566.494 (Published 31 August 2006) Cite this as: BMJ 2006;333:494All rapid responses
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Dear Sir,
As a General Practitioner dealing fairly frequently with the
management of possible food allergy and trying to assess the severity, I
was suprised that no mention was made in the two articles about
antihistamines.
I am under the impression that antihistamines should be administered
as soon as any reaction appears to be happening. This is standard advice
on any protocol about allergy management. To have a discussion about
potential fatal anaphylaxis and not to mention prompt use of
antihistamines seems narrowminded.
The carriage and prompt use of antihistamines followed by immediate
access to ambulance or hospital seems the best advice for all allergy
sufferers with carriage of adrenaline restricted to thse where assessment
points to severe risk. Although this will not prevent the very rare
catastophic reaction it is the most pragmatic approach for most people. It
is my experiance that adrenaline carriage induces significent anxiety in
both the child and those caring for the child especially on an
intermittant basis like friends and teachers. At times children are not
taken on school trips as the teacher will not take responsibility for the
chance of a reaction that would require injection but is quite happy to
give antihistamine.
Rupert Gude
Competing interests:
None declared
Competing interests: No competing interests
I'm a card-carrying patient with confirmed allergies to multiple
foods, and an associated astronomically high total and specific IgE to
counter any doubters. I read both sides of the published argument in the
print version of the BMJ with great interest, and so offer a patient's
perspective.
I endured 21 years of severe eczema, sleep deprivation, social stigma
and more Betnovate than you could paint the Forth Bridge with. When my
'childhood' eczema failed to do the decent thing, as I had been promised,
and go away of its own accord, the dermatologist shrugglingly told me I
now had 'adult' eczema and discharged me. What a shame no one had the
courage to do an exclusion diet in my toddler years and before I started
school.
Many of the nutritional concerns raised about doing exclusion diets
are voiced particularly in the context of treating or investigating
children. An exclusion diet is not something to be afraid of: do it right
and you only need to do it once! Don't do it at all, and you will be
condemning an unknown proportion of your patients to years of avoidable
suffering, both physical and psychological.
Done correctly, an exclusion diet need not be continued long enough
for anyone to get malnutrition. Any benefit (or not) from strict allergen
avoidance is normally clear in under a month, after which the diet can
either be abandoned because it didn’t work, or be incrementally expanded
to a nutritionally complete diet and from there to a socially convenient
one. Three months into a competently executed programme, with adequate
support of a dietician or a nutritionist, no patient should be in a
position where their diet is too restricted, either nutritionally or
socially.
The main difficulty for doctors and patients alike, is that there are
hardly any NHS specialist centres to refer patients to. In the absence of
appropriate support, many sufferers never even consider food allergen
avoidance. A minority self-construct exclusion diets but these are often
flawed in design or execution: too many potential allergens still in the
diet, or very commonly failure to completely exclude any of the allergens
as actually intended. An obvious risk of this state of affairs is patients
incorrectly concluding they have no food allergies. A less obvious risk of
poorly executed exclusion diets is of withdrawal flare or
hypersensitisation reactions.
Eventually, two decades after my eczema and asthma first erupted, an
unusually enlightened dermatologist diagnosed my food allergies. Further
investigation and follow up was limited to an immunologist offering
further (false) hope that I could still grow out of it. But, if I didn't
I'd have to cope on my own. I’m 41 now : no change so far.
Anandan's 10-minute consultation (BMJ 2 Sep 2006) shows that at least
there are some clinicians interested in paediatric food allergy prevention
and management, though the evidence base remains weak and Hu's
observations suggest poor consensus on how to interpret what limited
evidence exists. But who is looking after the adults?
The lack of any interest in supporting or investigating serious food
allergy sufferers became relevant again when I had children. There was,
and is, no one I could turn to for advice on allergy prevention. Whilst
there is plenty of generalised advice, such as that found in the 10-minute
consultation, there is none specific to cases where the mother already has
known IgE mediated severe food allergies. For example, can allergy be
passively transferred even temporarily via immunoglobulins in breast milk,
in the same way that we understand passive immunity? This became highly
relevant when my first son failed to thrive on breast milk, despite
careful maternal diet control. Breast milk allergy was diagnosed and
happily he accepted the taste of elemental amino acid formula milk and
thrived on it. I approached the birth of my second son, 2 years later,
with some trepidation: to breast feed or not? We flipped a coin, and in
fact he thrived on breast milk alone. But only in the paediatrician did I
finally find someone who could give me sound and up-to-date advice about
my own allergies!
Finally, all three articles appear to be me to be working from the
tacit premise that death is the only adverse outcome of food allergy worth
considering real or worthy of either investigation or intervention. This
seems entirely misguided, as are many of the concerns that children risk
being socially excluded because of the necessary treatment of their
allergies. This is nothing compared to the playground stigma and social
exclusion that goes with having untreated, unmanaged and unexplained
severe atopic skin or lung disease. I would gladly have traded the
miseries my eczema brought me throughout childhood, for a diet that didn’t
quite let me eat everything my friends did.
Speaking as a patient who considers herself largely failed by the
medical profession, the true 'dangers' of food allergy aren't exaggerated
- they're either not recognised at all as dangers, or are disregarded on
the grounds that if it doesn't kill you (and it very probably won't),
you'll most likely grow out of it. Do we know how often this is actually
true in modern times and populations, such that playing the numbers game
in this way might be justified? And what of people like me?
Competing interests:
None declared
Competing interests: No competing interests
Allan Colver’s comments on childhood food allergy [1] contains
several erroneous statements which could significantly endanger patients
if taken as evidence-based by clinicians inexperienced in dealing with
allergic disorders.
To address these in the order mentioned in the text:
1.Although the type of allergen is not in itself clearly predictive
of severity, certain allergens are much more frequently associated with
very severe reactions – so the likely culprit allergen cannot be ignored
as certain allergens trigger reactions at very low exposure levels [2].
2.The amount of allergen clearly does affect severity of reactions;
this is why anti-IgE monoclonal antibody therapy holds so much promise in
protecting children with peanut allergy, as the amount of allergen
required to cause a reaction increases after therapy [3].
3.The size of the skin prick wheal and/or the level of specific IgE
clearly predict the likelihood of a reaction on subsequent exposure, and
the papers quoted by Professor Colver contain the necessary evidence of
the positive predictive values for each allergen [4, 5]. Interpretation of
the results requires a good estimate of the pre-test probability of
allergy, and knowledge of the positive predictive values for the allergen
test (specific IgE or skin prick test wheal size). This can obviate the
need for doing a challenge test, so these investigations are essential in
the work up of suspected allergy.
4.Our understanding of which allergens are relevant is increasing,
and it has now been proven that IgE against certain molecular structures
within peanut allergens is clearly associated with reaction severity [6].
Yours sincerely,
Sujoy Khan, Carrock Sewell
References:
1. Colver AF. For and against: the dangers of childhood food allergy
are probably exaggerated. BMJ 2006; 333: 494-498.
2. Moneret-Vautrin DA, Rance F, Kanny G, Olsewski A, Gueant JL, Dutau
G, Guerin L. Food allergy to peanuts in France--evaluation of 142
observations. Clin Exp Allergy. 1998; 28(9): 1113-9.
3. Leung DY, Sampson HA, Yunginger JW, Burks AW Jr, Schneider LC,
Wortel CH, Davis FM, Hyun JD, Shanahan WR Jr; Avon Longitudinal Study of
Parents and Children Study Team. Effect of anti-IgE therapy in patients
with peanut allergy. N Engl J Med. 2003; 348(11): 986-93.
4. Hill DJ, Heine RG, Hosking CS. The diagnostic value of skin prick
testing in children with food allergy. Pediatr Allergy Immunol. 2004 ;
15(5):435-41.
5. Sampson HA, Ho DG. Relationship between food-specific IgE
concentrations and the risk of positive food challenges in children and
adolescents. J Allergy Clin Immunol. 1997; 100(4): 444-51.
6. Astier C, Morisset M, Roitel O, Codreanu F, Jacquenet S, Franck P,
et al. Predictive value of skin prick tests using recombinant allergens
for diagnosis of peanut allergy. J Allergy Clin Immunol 2006;118(1):250-6.
Competing interests:
None declared
Competing interests: No competing interests
While Prof. Allan Colver finds the risks of fatality in food allergic
children
overstated and epinephrine overprescribed, your readers will want to
consider
the views of the American Academy of Allergy Asthma & Immunology, and
research presented at the AAAAI's annual conference this past March. AAAAI
finds epinephrine under-used or not used promptly, and a failure to
recognize symptoms and report anaphylaxis at hospital.
To quote from AAAAI's news release on the topic: "While allergy-related visits
account for approximately 1 percent of all emergency room visits, the
number of visits recorded as being due to anaphylaxis is underestimated,
according to new research.
"Carlos A. Camargo, Jr., MD, DRPH, and Sunday Clark, MD,
Massachusetts
General Hospital, Boston, MA, and colleagues used the National Hospital
Ambulatory Medical Care Survey to obtain a sample of emergency department
visits between 1993 and 2003. The study showed there were a total of 11.4
million allergy-related visits over the 10-year span, with the number
remaining relatively stable each year. The study concluded that
anaphylaxis
coding was rare (1 percent) and that, based on other emergency department
studies, anaphylaxis is grossly underestimated. In addition, the study
showed
that between 1993 and 2003, life-saving epinephrine was under-utilized."
The AAAAI release (www.aaaai.org/media/news_releases/2006/03/030506.stm) further cites a survey that found only 6 percent of people
suffering the symptoms of allergic reaction (including severe symptoms)
used
epinephrine before going to hospital. Contrary to finding epinephrine over
-
prescribed or used, the AAAAI sent a news release to the U.S. media,
calling
for better education of food allergic individuals and their families.
As well, in an interview with the consumer magazine, Allergic Living,
of which
I'm the editor, the AAAAI's president, Dr. Estelle Simons, expressed
concern
about the under-recognition of anaphylaxis among both medical
professionals and the community at large (www.allergicliving.com/feature.asp?feature=19). "With anaphylaxis, we are now where we were with
asthma 30 years ago," said Dr. Simons. "Lack of recognition is a major
issue
for our patients and their families." She continued: "It should be public
policy
to teach people that anaphylaxis can be fatal and that lives can be saved
by
prompt injection of epinephrine."
I thought this information would be of interest.
Competing interests:
None declared
Competing interests: No competing interests
Given the implications of this debate1,2 for clinical decision making
and on the lives of families3, we have been conducting a qualitative study
on how allergists construe the risk of anaphylaxis to food in children.
We recruited all medical consultants (n = 15) from three specialist
paediatric allergy clinics, conducted interviews and recorded
consultations. Thematic analysis demonstrated a spectrum of widely
differing physician views on the risks. At one extreme, the risks were
construed to be low, augmented by “erroneous” parental perceptions and the
media. This was associated with a reduced likelihood of recommending
significant interventions such as adrenaline autoinjectors and avoidance
of all trace contaminants in foods. Death was the key problem, and since
deaths were rare, and interventions medically unproven, the default
position was to not intervene. Objective and reproducible assessments were
valued over parental perspectives.
At the other extreme, views associated with a greater likelihood of
intervention emphasised the unpredictability of future reactions over the
frequency of past events. Interventions were not just to prevent death,
but also negative experiences of reactions, and provided a sense of
security and control. Risk arose not only from biological factors, but
from the environment and human interactions. Parental experiences thus
provided a better understanding of risk and its management.
The debate1,2 reflects these findings, indicating that they are
generalisable beyond our research setting. The problem is not so much a
lack of expertise, but that in the face of uncertainty, even a highly
selected group of experts will markedly disagree. Such uncertainties will
increase as medicine moves towards the margins of therapeutic
effectiveness. Consumer participation and shared decision making have been
proposed as strategies4,5 but our findings suggest that these remain
problematic given doctors’ differing interpretations of risk, and of what
constitutes valid evidence.
Dr. Wendy Hu (corresponding author)
Conjoint Lecturer
School of Public Health and Community Medicine, University of New South
Wales, Sydney, Australia
Prof. Andrew Kemp
Professor of Paediatric Allergy, The Children’s Hospital at Westmead,
Discipline of Paediatrics and Child Health, University of Sydney
Prof. Carol Grbich
Professor, School of Medicine, Flinders University
This research has been funded by a National Health and Medical
Research Council of Australia grant, ID no 297112. The authors have no
competing interests to declare.
1 Colver A. Are the dangers of childhood food allergy exaggerated?
BMJ 2006;333:494-6
2 Hourihane JO. Are the dangers of childhood food allergy
exaggerated? BMJ 2006;333:496-8
3 Hu W, Kemp A, Kerridge I. Making clinical decisions when the stakes
are high and the evidence unclear. BMJ 2004;329:852-4
4 Edwards A, Elwyn G (eds) 2001. Evidence-Based Patient Choice:
Inevitable or Impossible? Oxford University Press
5 O’Connor AM, Legare F, Stacey D. Risk communication in practice:
the contribution of decision aids. BMJ 327:736-40.
Competing interests:
None declared
Competing interests: No competing interests
As the parent of a child with nut allergy and the organiser of The
Allergy Show - which attracts some 7,000 allergy sufferers and healthcare
professionals, I take issue with Prof Colver's article.
He fails to support adequately his hypothesis that the dangers of
childhood food allergy are exaggerated. He cites no evidence about
perception of risk other than three newspaper headlines - and he does not
show that the headlines are in any way wrong or exaggerated. He quotes
the fact that not many children die, but that does not show that risks are
exaggerated.
The evidence is that there are tens if not hundreds of thousands of
children who are allergic to nuts - but who have not received
proper advice. The House of Commons Select Committee on health estimates
that 250,000 children are allergic to peanuts - yet the prescription data
implies that only a small fraction are prescribed adrenaline auto-
injectors. Because nut allergy is unpredictable and the fact that past
reactions have been mild does not imply that future reactions will not be
severe, many allergists believe that all children with nut allergy should
carry adrenaline - not just those with asthma or a history of severe
reactions.
His article has too many inconsistencies to list - but here are a
few.
When he writes, about the prevalence of severe reaction, "Surely such
information needs to be known before dangers can be assessed?" he puts the
case that we don't have enough information to assess risk. Why then does
he think he has enough infromation to say that risks are exaggerated? Does
he know something the rest of us don't?
In writing "Only 6 of the 58 children might have benefited from
autoinjectors" he is surprisingly selective in his analysis of the data.
Why look at only the sub-set of 58 that he defines as "severe cases"
rather than the full sample of 229 children admitted to hospital with
allergic reactions - that medical staff thought severe enough to warrant
admission?
To say children who were experiencing their first allergic reaction
might not have benefited from adrenaline by definition is just plain wrong
- all you can say about them is that the fact that they didn't have
adrenaline was not a result of any failure - of course they might have
benefited.
To make a statement like "We have no evidence that the following
predict severity: Type of allergen..." defies common sense. Any well
informed layman knows that whilst egg allergy is extremely common in
children, peanut allergy is much more likely to result in a severe
reaction.
He happily states that "liberal prescription of autoinjectors can
cause anxiety" without in any way backing it up. Elsewhere he
acknowledges that "an autoinjector may reduce their anxiety". He can't
seem to make up his mind whether "Parents with autoinjectors feel the
responsibility greatly" or whether parents are so blase that they can't be
bothered to find out how to use them properly or check whether they are
unexpired.
250,000 children like my son live with peanut allergy. My experience
is that most of them successfully avoid peanuts for most of the time but
that large numbers of their parents are unaware of
the risks. Prof Colver should be doing more to educate people about real
risks rather than playing God - on the basis that not many of these
children are likely to die.
Competing interests:
Director of The Allergy Show - an exhibition for people with allergies and healthcare professionals
Competing interests: No competing interests
adrenaline saves lines
studies of deaths and hospital admissions do not provide the full
story. My child had an anaphylactic reaction to food last year.
Antihistamine was administered with no effect. It may help in less severe
reactions but would not prevent death, it is not a substitute for
adrenaline.
My child responded well to the epipen and we did not go to hospital.
Therefore the reaction appears in no studies and is not deemed "serious".
However as we live some distance from the hospital it could have been
fatal without the adrenaline. If you want to properly assess the risks of
food allergy you need to talk to those diagnosed as having food allergy.
For those who carry epipens and know how to use them the risk of
death is small. This reduces anxiety and allows the person to have more
normality in their social life. Those who do not have epipens or do not
have proper training in their use feel more anxious and are likely to call
for ambulances or require hospital admission. For my child's first
reaction I had to call for NHS help - now I don't. The saving in NHS
resources from the prescription of epipens needs to be included in cost
assessments. You also need to consider the social cost for families.
Good information about the frequency of reactions and the low number
of deaths would reduce anxiety and make the true benefits of adrenaline
clearer. May I respectfully suggest that someone mount a study based on
hospital records of those having positive skin prick tests?
Competing interests:
child who has had anaphylactic reaction to peanut and possibly other foods
Competing interests: No competing interests