The number of young people who had a food or digestive allergy increased 18 percent between 1997 and 2007, according to a new report by the Centers for Disease Control and Prevention. In 2007, approximately 3 million U.S. children and teenagers under age 18 – or nearly 4 percent of that age group – were reported to have a food or digestive allergy in the previous 12 months, compared to just over 2.3 million (3.3 percent) in 1997.
The findings are published in a new data brief, “Food Allergy Among U.S. Children: Trends in Prevalence and Hospitalizations.” The data are from the National Health Interview Survey and the National Hospital Discharge Survey, both conducted by CDC′s National Center for Health Statistics.
The report found that eight types of food account for 90 percent of all food allergies: milk, eggs, peanuts, tree nuts, fish, shellfish, soy, and wheat. Reactions to these foods by an allergic person can range from a tingling sensation around the mouth and lips, to hives and even death, depending on the severity of the reaction.
Children with food allergy are two to four times more likely to have other related conditions such as asthma and other allergies, compared to children without food allergies, the report said.
Other highlights:
* Boys and girls had similar rates of food allergy – 3.8 percent for boys and 4.1 percent for girls.
* Approximately 4.7 percent of children younger than 5 years had a reported food allergy compared to 3.7 percent of children and teens aged 5 to 17 years.
* Hispanic children had lower rates of reported food allergy (3.1 percent) than non-Hispanic white (4.1 percent) or non-Hispanic black children (4 percent.)
* In 2007, 29 percent of children with food allergy also had reported asthma compared to 12 percent of children without food allergy.
* Approximately 27 percent of children with food allergy had reported eczema or skin allergy, compared to 8 percent of children without food allergy.
* Over 30 percent of children with food allergy also had reported respiratory allergy, compared with 9 percent of children with no food allergy.
* From 2004 to 2006, there were approximately 9,537 hospital discharges per year with a diagnosis related to food allergy among children from birth to 17 years. Hospital discharges with a diagnosis related to food allergy increased significantly over time between 1998-2000 through 2004-2006.
The mechanisms by which a person develops an allergy to specific foods are largely unknown. Food allergy is more prevalent in children than adults. Most affected children will outgrow food allergies, although food allergy can be a lifelong concern.
Food allergy is a potentially serious immune response to eating
specific foods or food additives. Eight types of food account for over
90% of allergic reactions in affected individuals: milk, eggs, peanuts,
tree nuts, fish, shellfish, soy, and wheat. Reactions to these
foods by an allergic person can range from a tingling sensation around
the mouth and lips and hives to death, depending on the severity of the
allergy. The mechanisms by which a person develops an allergy to
specific foods are largely unknown. Food allergy is more prevalent in
children than adults, and a majority of affected children will "outgrow”
food allergies with age. However, food allergy can sometimes become a
lifelong concern. Food allergies can greatly affect children and
their families’ well-being. There are some indications that the
prevalence of food allergy may be increasing in the United States and in
other countries .
Keywords: allergy
, National Health Interview Survey
, National
Hospital Discharge Survey
Four out of every 100 children have a
food allergy
.

In 2007, an estimated 3 million children under age 18 years (3.9%)
had a reported food allergy.
Children under age 5 years had higher rates of reported food allergy
compared with children 5 to 17 years of age. Boys and girls had similar
rates of food allergy.
Hispanic children had lower rates of reported food allergy than
non-Hispanic white or non-Hispanic black children.
Food allergy among children in the United
States is becoming more common over time
.
In 2007, the reported food allergy rate among all
children younger than 18 years was 18% higher than in 1997. During the
10-year period 1997 to 2006, food allergy rates increased significantly
among both preschool-aged and older children.

Children with food allergy are more likely to
have asthma or other allergic conditions
.
In 2007, 29% of children with food allergy also had reported asthma
compared with 12% of children without food allergy.

Approximately 27% of children with food allergy had reported eczema
or skin allergy, compared with 8% of children without food allergy.
Over 30% of children with food allergy also had reported respiratory
allergy, compared with 9% of children with no food allergy.
Recent data show hospitalizations with diagnoses related to food
allergies have increased among children
.
From 2004 to 2006, there were an average of 9,537 hospital discharges
per year with a diagnosis related to food allergy among children 0 to 17
years.

Hospital discharges with a diagnosis related to food allergy
increased significantly over time from 1998-2000 through 2004-2006.
Summary
Reported food allergy has increased among children of all ages in the
United States over the last 10 years. Nationally representative survey
data corroborates reports of increasing food allergy in the United
States, and our findings are similar to those reported in other
countries. There is some difference in reported food allergy according
to Hispanic ethnicity, with lower reported rates among Hispanic children
compared with non-Hispanic white and non-Hispanic black children.
However, reported food allergy does not appear to differ by sex.
Children with food allergy are two to four times as likely to
experience other allergic conditions and asthma than children without
food allergy. This is of great importance as children with coexisting
food allergy and asthma may be more likely to experience anaphylactic
reactions to foods and be at higher risk of death.
Hospitalizations having at least one diagnosis related to food
allergy also increased from 1998-2000 through 2004-2006. This finding
could be related to increased awareness, reporting, and use of specific
medical diagnostic codes for food allergy or could represent a real
increase in children who are experiencing food-allergic reactions.
Definitions
-
Reported food allergy, National Health Interview Survey (NHIS):
is defined by an affirmative answer to the question "During the past
12 months, has (child) had any kind of food or digestive allergy?”
-
Food allergy diagnosis, National Hospital Discharge Survey (NHDS):
is defined by the International Classification of Diseases, Ninth
Revision, Clinical Modification (ICD-9-CM) codes relevant to food
allergy and anaphylaxis related to food allergy.
-
Reported asthma (NHIS): is defined by an affirmative answer to
the question "Has a doctor or health professional ever told you that
(child) had asthma?”
-
Reported eczema or skin allergy (NHIS): is defined by an
affirmative answer to the question "During the past 12 months, has
(child) had eczema or any kind of skin allergy?”
-
Reported respiratory allergy (NHIS): is defined by an
affirmative answer to the question "During the past 12 months, has
(child) had any kind of respiratory allergy?”
Data source and methods
The National Health Interview Survey (NHIS) was used in this analysis
to estimate the prevalence of food allergy among children in the United
States. The NHIS is a multipurpose health survey conducted by the
Centers for Disease Control and Prevention’s National Center for Health
Statistics, and is the principal source of information on the health of
the civilian, noninstitutionalized, household population of the United
States. The NHIS consists of a Basic Module and variable Supplements.
The Basic Module, which remains largely unchanged from year to year,
consists of three components: the Family Core, the Sample Child Core,
and the Sample Adult Core. Questions from the child core related to food
allergy, asthma, and other allergic conditions were used for this
analysis. The 2007 NHIS questionnaire containing these questions can be
viewed at:
http://www.cdc.gov/nchs/nhis.htm.
The NHIS uses a multistage sample designed to represent the civilian
noninstitutionalized population of the United States. In 2007,
approximately 9,500 children were sampled. Each sampled child is
assigned a weight in order to reflect their representation of the U.S.
child population. In order to make estimates on a national level, it is
necessary to utilize the person’s basic assigned sampling weight for
proper analysis. Therefore, the data for this analysis were weighted to
make national estimates.
The National Hospital Discharge Survey (NHDS) was used in this
analysis to estimate the number of hospital discharges among children
attributable to food allergy. The NHDS is a national probability survey
designed to meet the need for information on characteristics of
inpatients discharged from nonfederal short-stay hospitals in the United
States. The NHDS collects data from a sample of approximately 270,000
inpatient records acquired from a national sample of about 500
hospitals. Only hospitals with an average length of stay of fewer than
30 days for all patients, general hospitals, or children’s general
hospitals are included in the survey. Federal, military, and Department
of Veterans Affairs hospitals, as well as hospital units of institutions
(such as prison hospitals), and hospitals with fewer than six beds
staffed for patient use, are excluded.
The NHDS uses a three-stage sampling design procedure to produce
national estimates of hospital discharges. Weights are assigned to each
sample record. When used collectively, the sample is representative of
the United States.
A maximum of seven diagnostic codes was assigned for each sample
abstract. Further information about the NHDS can be found at:
http://www.cdc.gov/nchs/about/major/hdasd/nhds.htm.
The ICD-9-CM codes used to identify food allergy in the NHDS included
477.1 (allergic rhinitis due to food), 558.3 (allergic gastroenteritis
and colitis), 692.5 (contact dermatitis due to food in contact with
skin) 693.1 (dermatitis due to food taken internally), 995.6
(anaphylactic shock due to adverse food reaction with specific codes for
unspecified food, peanuts, crustaceans, fruits and vegetables, tree nuts
and seeds, fish, food additives, milk products, eggs, other specified
food), and 995.7 (other adverse food reactions not elsewhere
classified). Trend tests were performed to evaluate changes in reported
food allergy over time using weighted least squares regression.
Chi-square tests were performed to evaluate differences in food allergy
between groups. All estimates shown have an unweighted sample size of 30
or greater and a relative standard error less than or equal to 30%. All
significance tests were two-sided using p < 0.05 as the level of
statistical significance. Terms such as "similar” indicate that the
statistics being compared were not statistically significant. All data
analyses were performed using the statistical packages SAS version 9.1
(SAS Institute, Cary, N.C.) and STATA.
About the authors
Amy M. Branum and Susan L. Lukacs are with the Centers for Disease Control
and Prevention’s National Center for Health Statistics, Office of Analysis and
Epidemiology, Infant, Child, and Women’s Health Statistics Branch.
References
-
Sampson HA. Update on food allergy. J Allergy Clin
Immunol; 113:805-19. 2004.
-
Sicherer SH. Food allergy. Lancet; 360:701-10. 2002.
-
Sicherer SH, Munoz-Furlong A, Sampson HA. Prevalence of peanut and tree
nut allergy in the United States determined by means of random digit dial
telephone survey: a 5-year follow-up study. J Allergy Clin Immunol;
112:1203-7. 2003.
-
Grundy J, Matthews S, Bateman B, Dean T, Arshad SH. Rising prevalence of
allergy to peanut in children: data from 2 sequential cohorts. J Allergy
Clin Immunol; 110:784-9. 2002.
-
Bock SA, Munoz-Furlong A, Sampson HA. Further fatalities caused by
anaphylactic reactions to food, 2001-2006. J Allergy Clin Immunol;
119:1016-18. 2007.
-
Colver AF, Nevantaus H, Macdougall CF, Cant AJ. Severe food-allergic
reactions in children across the UK and Ireland, 1998-2000. Acta Paediatr;
94:689-95. 2005.