July 2007
FALSE BELIEFS :
"Infantile atopic
dermatitis is a skin disease and is not related to
allergy."
This is wrong since infantile atopic dermatitis occurs in the event of one,
or several, food allergies. However, it is true that food allergy may disappear
over time, but other sensitizations will appear, and may replace food allergens
in sustaining atopic dermatitis. It is also true that the skin of patients
with atopic dermatitis is different, and even if allergy is not detected, any
lesions in skin folds will not disappear (elbow folds, the back of the knees,
wrists, neck folds, folds behind the ears and under eyelids, etc.). "My child
is too young to have allergy tests."
This is a grave error. After 3 months of age, most infants can undergo skin
tests. Under 3 months of age, two thirds of the infant population can
undergo skin tests. Onset of allergy can occur at a very early age: between
15 days and one month, but by the time children see an allergologist, they
may be 3 months old. Early diagnosis of food allergy helps manage the
disorder, and symptoms will resolve all the quicker if effective treatment
is implemented." "When an infant has an
allergy, it is nearly always caused by milk. All I
need to do is follow the pediatrician's prescription
and give my baby a milk substitute. If symptoms resolve,
the diagnosis was correct and my baby needs no further
allergy tests."
This is true... and not true. It all depends
on the intensity of symptoms. If these are moderate gastrointestinal
disorders, we know that the child will recover naturally,
usually between the age of 10 to 15 months. In this case
allergy tests need not be performed. But if symptoms
are more serious, or if the clinical picture resembles
atopic dermatitis, allergy tests should be carried out.
Results can then be compared with those of later tests,
performed at the age of about 18 months (or a bit earlier)
to see whether milk can be re-introduced without risk. ANAPHYLAXIS IS THE MOST
SERIOUS FORM OF ALLERGY.
A FEW RECOMMENDATIONS… "When a person with food
allergy goes into anaphylactic shock, we must wait
for the emergency ambulance team to administer Anapen,
the self-injectable syringe of epinephrin".
Certainly not ! The earlier a patient receives
epinephrin, the more effective it is! It is useful
to know that the earlier the onset of anaphylactic
shock (within minutes of eating the allergen), the
more severe the reaction will be. Injecting Anapen
immediately can save lives.
Unfortunately, it is impossible to know if and when a serious accident will
occur when only moderate reactions have been seen in the past. This is why
the symptoms of immediate allergy to food must be controlled every year by
an allergist (if possible by the same physician and with the same laboratory
test techniques). If, despite a well-conducted avoidance diet, a new allergic
reaction occurs, the allergist must be informed. He/she will then decide
whether the patient should be seen again.
If a child with food allergy is also asthmatic, it is very important to implement
daily treatment by inhaled drugs and to assess its efficacy. Warning! When
children with food allergy have a viral infection or any other condition
that upsets the body functions, they are at increased risk of acute asthma
if they eat something unexpected. Unstable asthma in patients with food allergy
must be controlled by adequate treatment. Food allergic children
at school :
If the child requires
individual attention at school,
documentation (the care management
project) must contain specific
details, not only about health
care measures in the event of onset of symptoms, but
also the type of school meals they can eat! For example: "the
child should not eat tree nuts" is far too vague. It
is essential to notify: 1) eating at the school canteen
is not allowed (this is very rare), 2) eating food
prepared by the parents in the school canteen is allowed
(more frequent), 3) eating commercial preparations
of hypoallergenic food in the school canteen is allowed
(this is often expensive), 4) normal canteen meals
are allowed but certain foods are restricted (i.e.:
kiwi). This last option can be applied to adolescents
on eviction diets who have had no reactions since childhood
and who are mature enough to differentiate foods for
themselves. From a mother
: "I
have an emergency kit which I know how to use and
if Jules has an allergic reaction I do not need to
bother the doctor."
OK, but... although the emergency procedures
(administration of anti-histamines and corticosteroids,
or sometimes even epinephrin) carried out by parents
are vital, they may remain insufficient. You must call
your doctor who will assess the potential seriousness
of the reaction, or go to the Emergency Unit at your
local hospital.
Allergist, CICBAA*
Allergy staff, 2007
*Circle of Clinical and Biological Investigations in Food Allergy
Safety of prick-tests
using food allergens - sept 2006
Prick-tests to foods are usually carried out
as the first step in the diagnosis of food allergy.
Severe anaphylaxis accounts for 4.9 % of allergies
in children and occurs more frequently in adults, raising
the possibility of systemic reactions to prick-tests
in highly sensitized people. Several studies published
in the literature have used commercial extracts. As
for airborne allergens, concentrations causing a skin
reaction of 15 mm do not present a risk of systemic
reactions. Prick-tests to native foods--prick-in-prick
tests--have been less extensively studied. The CICBAA1
data, from 1,138 food allergic patients of all ages,
cover 34,905 prick-in-prick tests to foods. The wheal
of these prick-tests has been regulary registered.
The risk of systemic reactions can be evaluated at
0.008 %. There were no severe reactions and anti-histamine
and corticosteroid therapy were sufficient. These results
are similar to those of the large study in 2000 carried
out by Devenney in neonates (0.005%). A review of the
literature reveals only a few severe reactions in adults.
The authors draw attention to the necessary precautions:
temporary contra-indication for skin prick-tests in
children and adults with grade 3 or 4 asthma, with
particular attention to such foods as all kinds of
nuts, fish, etc. Codreanu F,
Moneret-Vautrin DA, Morisset M, Guenard L, Rance F, Kanny
G, Lemerdy P. The risk of systemic reactions to skin prick-tests
using food allergens: CICBAA data and literature review.
Allerg Immunol 2006;38:52-4
The U.S.A. have just adopted a
legislation concerning the compulsory labelling of
the eight major food allergens
Watch
out for masked
allergens
New directives on labelling
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