Abstract
Background
Although previous studies have focused on unintentional food-related allergic reactions, few have explored the motivation of intentional exposure to a known food allergen, independent of oral food challenges and/or oral immunotherapy. Still, data on the frequency and context of food-related allergic reactions remain sparse.
Objective
To identify the frequency and context of food-related allergic reactions among children and adults.
Methods
We analyzed surveys from the Patient Registry established by Food Allergy Research and Education. Multivariable logistic regression evaluated characteristics associated with having frequent food-related allergic reactions as well as intentional food-related allergic reactions.
Results
Over one-third of 4075 (37.7%) respondents reported having more than 1 food-related allergic reaction per year, and 12.8% reported having 1 reaction per year. Of the 3054 respondents who completed the most recent reaction survey, 9.9% of food allergen exposures were classified as intentional, 82.1% as unintentional, and 4.8% as medically related. Among children with intentional exposures, the most common reason was that the child had never had a serious reaction (50.0%), and among adults, it was the decision to take the risk anyway (47.8%). Cross-contamination was the most commonly cited reason for unintentional exposure (children: 24.1%; adults: 32.2%).
Conclusion
Among patients in a national food allergy registry, reports of food-related allergic reactions were common, and a non-negligible number of intentional reactions were reported. Our findings indicate the need for research on reactions in and out of the emergency department as well as intentional risk-taking behavior.
Keywords: Food allergy, Food allergic reactions, Unintentional exposure, Intentional exposure, Reaction frequency, Reaction severity, Treatment
Recent prevalence studies estimate that up to 8% of children and 10.8% of adults in the United States have food allergy (FA), a condition that can cause potentially life-threatening allergic reactions with no known cure and limited treatments.1,2 Approximately 1 in 5 children with FA visit the emergency department (ED) every year for a food-related allergic reaction.3 In addition, the economic burden of FA is considerable with an estimated cost of $24.8 billion per year in the United States, with the largest out-of-pocket expense stemming from the purchase of safe food.4
Avoidance of allergenic food is challenging and limits the social sphere of children and adults living with FA. The impact on quality of life is substantial and often stems from the fear that an unintentional food exposure may lead to a severe food-related allergic reaction. Research on the lived experience of food-related allergic reactions, including frequency rate and reason for exposure, is largely based on small clinical samples that do not provide insight into the experience of the broader population of food-allergic individuals. In addition, previous research on the characteristics of food-related allergic reactions has mostly focused on unintentional exposures; however, a 2015 systematic review noted that even data on the frequency of unintentional reactions are scarce.5
Another aspect of the FA experience that has yet to be fully examined in the literature is the existence of intentional food-related allergic reactions. Although unintentional food-related allergic reactions may be due to cross-contamination, hidden allergens, food preparation errors, and/or label-reading errors, intentional reactions are due to purposeful exposure to the food allergen, of which the motivation is largely unknown.6 One prospective study of infants found that intentional exposure accounted for 11.2% of reactions to milk, egg, or peanut.6 However, there remains a lack of data on intentional exposure to food allergens among adults and older children. Therefore, the purpose of this study is to provide greater insight into the frequency and context of food-related allergic reactions in both children and adults. To accomplish this objective, we used data from a national registry of food-allergic individuals of all ages to describe the frequency, motivation, and self-perceived severity of unintentional and intentional food-related allergic reactions.
Methods
Data source
The primary data source for this study was Food Allergy Research and Education's (FARE) Patient Registry, a national online repository of data collected from participants with FA. Data collection is ongoing through the Invitae survey platform. Potential participants were informed about the Registry utilizing FARE's email list of over 200,000 FA-interested consumers. In addition, the Registry was advertised through social media posts, FARE websites, and local FA support groups. Allergists at 33 clinical research centers across the United States were provided with information to promote the Registry to their patients and allergists. The research protocol was approved by the institutional review board at Northwestern University.
The FARE Registry consists of 4 comprehensive surveys related to FA history (ie, FA History), reactions and symptomatology (ie, FA Reactions, FA Reactions II), and FA-related mental health service utilization (ie, Mental Health Services). A brief online registration included an electronic consent/assent form with subsequent survey prompts. Participation was voluntary, self-administered, and nonincentivized; FARE membership was not required. Eligibility criteria for the registry included the self-report of at least 1 physician-diagnosed current or outgrown FA.
In September 2019, a current cross-section of deidentified data was shared with Northwestern University, including the FA History survey (n = 4237) and FA Reactions survey (n = 3198). Inclusion/exclusion criteria were applied separately to each data source based on data cleaning and a priori considerations of relevant survey respondents. Exclusions were made based on the respondent's relationship to the food-allergic person, which was categorized as self or parent/guardian (mother/father/grandparent/other caregiver). Given the importance of this information with respect to the accurate reporting of FA-related data, respondents with missing data on this individual survey item were excluded (FA History, n = 61; FA Reactions, n = 43), as were spouses (FA History, n = 7; FA Reactions, n = 9). In addition, we excluded parents, grandparents, or other legal guardians who reported the food-allergic person's age as older than 26 years (FA History, n = 42; FA Reactions, n = 44), because we expected persons of this age range to be established independently. We also excluded respondents who reported themselves as the food-allergic person (ie, “self”) and were also under 18 years of age (FA History, n = 36; FA Reactions, n = 28), as well as respondents who reported implausible ages (ie, >100 years; FA History, n = 16; FA Reactions, n = 14). In addition, those with missing data on primary outcomes were excluded (FA Reactions, n = 6). Finally, there were 4075 eligible participants who completed FA History and 3054 eligible participants who completed FA Reactions.
Outcomes
Outcomes included the frequency of food-related allergic reactions and context of the most recent reaction. The frequency of reactions was measured by an FA History survey item (“On average, how many allergic reactions does the participant have per year?”) (see the FA History Survey, available in this article's Online Repository at www.jaci-inpractice.org ). Self-reported responses to this survey item were categorized as less than once per year, once per year, more than once per year, and unsure, never, or missing. Reaction context and treatment was reported in the FA Reactions Survey (available in this article's Online Repository at www.jaci-inpractice.org ). Respondents classified the food allergen exposure associated with the patient's most recent reaction as intentional (ie, nonaccidental/deliberate), unintentional (ie, accidental), or unsure. Responses specified as other were reviewed by the research team and led to the addition of a category for medical-related care (eg, oral food challenges). Reasons for intentional reactions referred to situations where a respondent was knowingly exposed to a known allergen. Exposures to new allergens were treated as unintentional. We also analyzed the type and location of food exposure, self-perceived severity of reaction, and subsequent treatment.
Demographic measures
Demographic data included patient age, gender, race, ethnicity, and state of residence. Age in years at the time of enrollment was calculated from the patient's date of birth. State of residence was classified into Northeast, Midwest, South, and West. Ethnicity was categorized as Hispanic/Latinx, non-Hispanic/Latinx, or unspecified/missing. Race was determined by pre-established survey categories (ie, white, black/African-American, Asian, American Indian or Alaskan Native, Native Hawaiian or Other Pacific Islander, Other). A multirace category was included to indicate whether respondents chose more than 1 race option.
Statistical analyses
Data from the consent/assent, FA History, and FA Reactions surveys were merged via a unique participant identifier to create a master data set from which the current analyses were performed. Demographic characteristics and survey item responses were evaluated with proportions and 95% confidence intervals (CIs) or medians and interquartile ranges (IQRs). Pearson's χ 2 statistics were used to test associations between categorical variables and type of respondent (self or parent/guardian). Multivariable logistic regression analyses were performed to determine the relationships between an a priori determined set of predictors and the odds of intentional allergen exposure and frequent annual reaction rate (ie, 1 or more reactions per year). With respect to survey items with missing data, estimates were calculated using the denominator of those who answered the particular survey item. Statistical tests were 2-sided with an alpha level of 0.05. All analyses were performed with Stata SE Version 15.1 (College Station, TX).
Results
Participant characteristics
Demographics.
A total of 4075 participants had complete data according to our criteria (Table I). Of those, approximately two-thirds (65.7%) represented parents or legal guardians of food allergic children, whereas one-third (34.3%) reported on their own FA. The majority of participants within the entire sample were female (54.6%; CI: 53.0%-56.1%), non-Hispanic/Latinx (63.4%; CI: 61.9%-64.9%), and under 18 years of age (median: 14.2 years; IQR: 7.6-28.7 years) at the time of online registration.
TABLE I.
Characteristics of FARE Registry respondents
| Parent/guardian respondent |
Self-respondent |
Total |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| N | % | 95% CI | N | % | 95% CI | N | % | 95% CI | |
| All respondents | 2679 | 100.0 | (100.0-100.0) | 1396 | 100.0 | (100.0-100.0) | 4075 | 100.0 | (100.0-100.0) |
| Age in years at registry enrollment | |||||||||
| <5 | 606 | 22.6 | (21.1-24.2) | NA | NA | NA | 606 | 14.9 | (13.8-16.0) |
| 5-12 | 1242 | 46.4 | (44.5-48.3) | NA | NA | NA | 1242 | 30.5 | (29.1-31.9) |
| 13-17 | 662 | 24.7 | (23.1-26.4) | NA | NA | NA | 662 | 16.2 | (15.1-17.4) |
| 18-25 | 169 | 6.3 | (5.4-7.3) | 279 | 20.0 | (18.0-22.2) | 448 | 11.0 | (10.1-12.0) |
| 26-66 | NA | NA | NA | 1024 | 73.4 | (71.0-75.6) | 1024 | 25.1 | (23.8-26.5) |
| >66 | NA | NA | NA | 93 | 6.7 | (5.5-8.1) | 93 | 2.3 | (1.9-2.8) |
| Gender | |||||||||
| Female | 1015 | 37.9 | (36.1-39.7) | 1208 | 86.5 | (84.6-88.2) | 2223 | 54.6 | (53.0-56.1) |
| Race | |||||||||
| White | 2244 | 83.8 | (82.3-85.1) | 1207 | 86.5 | (84.6-88.2) | 3451 | 84.7 | (83.5-85.8) |
| Black/African American | 37 | 1.4 | (1.0-1.9) | 44 | 3.2 | (2.4-4.2) | 81 | 2.0 | (1.6-2.5) |
| Asian | 92 | 3.4 | (2.8-4.2) | 31 | 2.2 | (1.6-3.1) | 123 | 3.0 | (2.5-3.6) |
| Native American/Alaskan Native | 4 | 0.1 | (0.1-0.4) | 11 | 0.8 | (0.4-1.4) | 15 | 0.4 | (0.2-0.6) |
| Pacific Islander | 4 | 0.1 | (0.1-0.4) | 0 | 0.0 | (0.0-0.0) | 4 | 0.1 | (0.0-0.3) |
| Multiracial | 233 | 8.7 | (7.7-9.8) | 57 | 4.1 | (3.2-5.3) | 290 | 7.1 | (6.4-7.9) |
| Unspecified/missing | 65 | 2.4 | (1.9-3.1) | 46 | 3.3 | (2.5-4.4) | 111 | 2.7 | (2.3-3.3) |
| Ethnicity | |||||||||
| Hispanic/Latinx | 199 | 7.4 | (6.5-8.5) | 75 | 5.4 | (4.3-6.7) | 274 | 6.7 | (6.0-7.5) |
| Non-Hispanic/Latinx | 1690 | 63.1 | (61.2-64.9) | 894 | 64.0 | (61.5-66.5) | 2584 | 63.4 | (61.9-64.9) |
| Unspecified/missing | 790 | 29.5 | (27.8-31.2) | 427 | 30.6 | (28.2-33.1) | 1217 | 29.9 | (28.5-31.3) |
| Region | |||||||||
| West | 459 | 17.1 | (15.8-18.6) | 271 | 19.4 | (17.4-21.6) | 730 | 17.9 | (16.8-19.1) |
| Midwest | 675 | 25.2 | (23.6-26.9) | 294 | 21.1 | (19.0-23.3) | 969 | 23.8 | (22.5-25.1) |
| South | 759 | 28.3 | (26.7-30.1) | 418 | 29.9 | (27.6-32.4) | 1177 | 28.9 | (27.5-30.3) |
| Northeast | 688 | 25.7 | (24.1-27.4) | 357 | 25.6 | (23.4-27.9) | 1045 | 25.6 | (24.3-27.0) |
| Unspecified/missing | 98 | 3.7 | (3.0-4.4) | 56 | 4.0 | (3.1-5.2) | 154 | 3.8 | (3.2-4.4) |
| Type of “Top 9” food allergy | |||||||||
| Peanut | 2147 | 80.1 | (78.6-81.6) | 656 | 47.0 | (44.4-49.6) | 2803 | 68.8 | (67.3-70.2) |
| Treenut | 1874 | 70.0 | (68.2-71.7) | 686 | 49.1 | (46.5-51.8) | 2560 | 62.8 | (61.3-64.3) |
| Egg | 1421 | 53.0 | (51.1-54.9) | 316 | 22.6 | (20.5-24.9) | 1737 | 42.6 | (41.1-44.2) |
| Milk | 1041 | 38.9 | (37.0-40.7) | 401 | 28.7 | (26.4-31.2) | 1442 | 35.4 | (33.9-36.9) |
| Shellfish | 384 | 14.3 | (13.1-15.7) | 424 | 30.4 | (28.0-32.8) | 808 | 19.8 | (18.6-21.1) |
| Fin fish | 217 | 8.1 | (7.1-9.2) | 195 | 14.0 | (12.2-15.9) | 412 | 10.1 | (9.2-11.1) |
| Wheat | 378 | 14.1 | (12.8-15.5) | 294 | 21.1 | (19.0-23.3) | 672 | 16.5 | (15.4-17.7) |
| Soy | 452 | 16.9 | (15.5-18.3) | 318 | 22.8 | (20.7-25.1) | 770 | 18.9 | (17.7-20.1) |
| Sesame | 502 | 18.7 | (17.3-20.3) | 177 | 12.7 | (11.0-14.5) | 679 | 16.7 | (15.5-17.8) |
| No. of food allergies | |||||||||
| Single food allergy | 470 | 17.5 | (16.1-19.0) | 399 | 28.6 | (26.3-31.0) | 869 | 21.3 | (20.1-22.6) |
| Multiple food allergies | 2209 | 82.5 | (81.0-83.9) | 997 | 71.4 | (69.0-73.7) | 3206 | 78.7 | (77.4-79.9) |
| Average no. of reactions | |||||||||
| Less than once per year | 1232 | 46.0 | (44.1-47.9) | 420 | 30.1 | (27.7-32.5) | 1652 | 40.5 | (39.0-42.1) |
| Once per year | 384 | 14.3 | (13.1-15.7) | 139 | 10.0 | (8.5-11.6) | 523 | 12.8 | (11.8-13.9) |
| More than once per year | 807 | 30.1 | (28.4-31.9) | 731 | 52.4 | (49.7-55.0) | 1538 | 37.7 | (36.3-39.2) |
| Never/unspecified/missing | 256 | 9.6 | (8.5-10.7) | 106 | 7.6 | (6.3-9.1) | 362 | 8.9 | (8.0-9.8) |
| Comorbidities | |||||||||
| Allergic rhinitis | 950 | 35.5 | (33.7-37.3) | 771 | 55.2 | (52.6-57.8) | 1721 | 42.2 | (40.7-43.8) |
| Asthma | 1199 | 44.8 | (42.9-46.6) | 786 | 56.3 | (53.7-58.9) | 1985 | 48.7 | (47.2-50.2) |
| Atopic dermatitis | 1579 | 58.9 | (57.1-60.8) | 459 | 32.9 | (30.5-35.4) | 2038 | 50.0 | (48.5-51.5) |
| Bee allergy | 25 | 0.9 | (0.6-1.4) | 166 | 11.9 | (10.3-13.7) | 191 | 4.7 | (4.1-5.4) |
| Contact dermatitis | 305 | 11.4 | (10.2-12.6) | 273 | 19.6 | (17.6-21.7) | 578 | 14.2 | (13.1-15.3) |
| Drug allergy | 275 | 10.3 | (9.2-11.5) | 576 | 41.3 | (38.7-43.9) | 851 | 20.9 | (19.7-22.2) |
| EOE | 111 | 4.1 | (3.5-5.0) | 76 | 5.4 | (4.4-6.8) | 187 | 4.6 | (4.0-5.3) |
| FPIES | 51 | 1.9 | (1.4-2.5) | 15 | 1.1 | (0.6-1.8) | 66 | 1.6 | (1.3-2.1) |
| OAS/PFAS | 195 | 7.3 | (6.4-8.3) | 253 | 18.1 | (16.2-20.2) | 448 | 11.0 | (10.1-12.0) |
CI, Confidence interval; EOE, eosinophilic esophagitis; FA, food allergy; FARE, Food Allergy Research and Education; FPIES, Food Protein-Induced Enterocolitis Syndrome; OAS, Oral Allergy Syndrome; PFAS, Pollen Food Allergy Syndrome.
Basic demographic information and relevant FA information was provided by parent/guardian respondents as well as self-respondents. Respondents were also asked to answer the average number of reactions they experience per year and list any diagnosed comorbidities.
Food allergy characteristics.
Overall, the most prevalent FAs were peanut (68.8%; CI: 67.3%-70.2%) and treenut (62.8%; CI: 61.3%-64.3%), whereas the least prevalent were wheat (16.5%; CI: 15.4%-17.7%) and fin fish (10.1%; CI: 9.2%-11.1%) (Table I). Most respondents had multiple FAs (78.7%; CI: 77.4%-79.9%). Common comorbidities included atopic dermatitis (50.0%; CI: 48.5%-51.5%), asthma (48.7%; CI: 47.2%-50.2%), and allergic rhinitis (42.2%; CI: 40.7%-43.8%).
Parent/guardian respondents reported fewer reactions per year, on average, than self-respondents. Specifically, 30.1% (CI: 28.4%-31.9%) of parent/guardian respondents reported that their child with FA had an average of more than 1 reaction per year compared with 52.4% (CI: 49.7%-55.0%) of self-respondents (P < .001). The proportion of respondents reporting 1 reaction per year was similar between the 2 groups (parent/guardian respondents, 14.3%; CI: 13.1%-15.7%; self-respondents, 10.0%; CI: 8.5%-11.6%).
Food-related allergic reaction characteristics
In total, there were 3054 participants with complete information on the characteristics of their most recent food-related allergic reaction (Table II). Among them, 40% reported on their own allergic reaction and 60.0% reported on their child's allergic reaction. Overall, 82.1% (CI: 80.7%-83.4%) of recent reactions were categorized as unintentional, whereas 9.9% (CI: 8.8%-11.0%) were categorized as intentional, 4.8% (CI: 4.1%-5.6%) were categorized as medically related, and 3.3% (CI: 2.7%-4.0%) were unsure. Both groups of respondents most often characterized their reaction as moderate (35.0%: CI: 33.3%-36.7%). Overall, 70.2% of respondents used antihistamines to treat reactions (70.2%; CI: 68.6%-72.8%), whereas 22.8% used epinephrine autoinjectors (EAIs) (22.8%; CI: 21.3%-24.3%) and 17.6% used oral corticosteroids (17.6%; CI: 16.3%-19.0%).
TABLE II.
Characteristics of most recent reaction of FARE Registry respondents
| Parent/guardian respondent |
Self-respondent |
Total |
|||||||
|---|---|---|---|---|---|---|---|---|---|
| N | % | 95% CI | N | % | 95% CI | N | % | 95% CI | |
| All respondents reporting reaction | 1847 | 1207 | 3054 | ||||||
| Context of reaction | |||||||||
| Accidental | 1463 | 79.2 | (77.3-81.0) | 1044 | 86.5 | (84.4-88.3) | 2507 | 82.1 | (80.7-83.4) |
| Nonaccidental (intentional) | 188 | 10.2 | (8.9-11.6) | 113 | 9.4 | (7.8-11.1) | 301 | 9.9 | (8.8-11.0) |
| Medical care related | 130 | 7.0 | (6.0-8.3) | 16 | 1.3 | (0.8-2.2) | 146 | 4.8 | (4.1-5.6) |
| Unsure | 66 | 3.6 | (2.8-4.5) | 34 | 2.8 | (2.0-3.9) | 100 | 3.3 | (2.7-4.0) |
| Age in years at time of reaction | 1847 | 1207 | 3054 | ||||||
| <5 | 982 | 53.2 | (50.9-55.4) | 67 | 5.6 | (4.4-7.0) | 1049 | 34.3 | (32.7-36.1) |
| 5-12 | 662 | 35.8 | (33.7-38.1) | 28 | 2.3 | (1.6-3.3) | 690 | 22.6 | (21.1-24.1) |
| 13-17 | 193 | 10.4 | (9.1-11.9) | 55 | 4.6 | (3.5-5.9) | 248 | 8.1 | (7.2-9.1) |
| 18-25 | 10 | 0.5 | (0.3-1.0) | 245 | 20.3 | (18.1-22.7) | 255 | 8.3 | (7.4-9.4) |
| 26-66 | 0 | 0.0 | (0.0-0.0) | 764 | 63.3 | (60.5-66.0) | 764 | 25.0 | (23.5-26.6) |
| >66 | 0 | 0.0 | (0.0-0.0) | 48 | 4.0 | (3.0-5.2) | 48 | 1.6 | (1.2-2.1) |
| Type of food allergen | |||||||||
| Peanut | 506 | 27.4 | (25.4-29.5) | 160 | 13.3 | (11.5-15.3) | 666 | 21.8 | (20.4-23.3) |
| Treenut | 308 | 16.7 | (15.0-18.4) | 191 | 15.8 | (13.9-18.0) | 499 | 16.3 | (15.1-17.7) |
| Egg | 219 | 11.9 | (10.5-13.4) | 54 | 4.5 | (3.4-5.8) | 273 | 8.9 | (8.0-10.0) |
| Milk | 253 | 13.7 | (12.2-15.3) | 107 | 8.9 | (7.4-10.6) | 360 | 11.8 | (10.7-13.0) |
| Shellfish | 23 | 1.2 | (0.8-1.9) | 83 | 6.9 | (5.6-8.4) | 106 | 3.5 | (2.9-4.2) |
| Fin fish | 22 | 1.2 | (0.8-1.8) | 20 | 1.7 | (1.1-2.6) | 42 | 1.4 | (1.0-1.9) |
| Wheat | 42 | 2.3 | (1.7-3.1) | 76 | 6.3 | (5.1-7.8) | 118 | 3.9 | (3.2-4.6) |
| Soy | 16 | 0.9 | (0.5-1.4) | 39 | 3.2 | (2.4-4.4) | 55 | 1.8 | (1.4-2.3) |
| Sesame | 53 | 2.9 | (2.2-3.7) | 31 | 2.6 | (1.8-3.6) | 84 | 2.8 | (2.2-3.4) |
| Beans | 35 | 1.9 | (1.4-2.6) | 11 | 0.9 | (0.5-1.6) | 46 | 1.5 | (1.1-2.0) |
| Cereals | 4 | 0.2 | (0.1-0.6) | 17 | 1.4 | (0.9-2.3) | 21 | 0.7 | (0.4-1.1) |
| Seeds (other than mustard, sesame) | 27 | 1.5 | (1.0-2.1) | 10 | 0.8 | (0.4-1.5) | 37 | 1.2 | (0.9-1.7) |
| Mustard | 5 | 0.3 | (0.1-0.6) | 7 | 0.6 | (0.3-1.2) | 12 | 0.4 | (0.2-0.7) |
| Meats | 8 | 0.4 | (0.2-0.9) | 35 | 2.9 | (2.1-4.0) | 43 | 1.4 | (1.0-1.9) |
| Herbs or spices | 4 | 0.2 | (0.1-0.6) | 28 | 2.3 | (1.6-3.3) | 32 | 1.0 | (0.7-1.5) |
| Fruits or vegetables | 54 | 2.9 | (2.2-3.8) | 98 | 8.1 | (6.7-9.8) | 152 | 5.0 | (4.3-5.8) |
| Other/unsure/missing | 268 | 14.5 | (13.0-16.2) | 240 | 19.9 | (17.7-22.2) | 508 | 16.6 | (15.4-18.0) |
| Processed or prepackaged food | |||||||||
| Yes | 954 | 51.7 | (49.4-53.9) | 467 | 38.7 | (36.0-41.5) | 1421 | 46.5 | (44.8-48.3) |
| No | 709 | 38.4 | (36.2-40.6) | 551 | 45.7 | (42.9-48.5) | 1260 | 41.3 | (39.5-43.0) |
| Unsure | 181 | 9.8 | (8.5-11.2) | 185 | 15.3 | (13.4-17.5) | 366 | 12.0 | (10.9-13.2) |
| Unspecified/missing | 3 | 0.2 | (0.1-0.5) | 4 | 0.3 | (0.1-0.9) | 7 | 0.2 | (0.1-0.5) |
| Self-perceived severity of reaction | |||||||||
| Mild | 467 | 25.3 | (23.4-27.3) | 315 | 26.1 | (23.7-28.7) | 782 | 25.6 | (24.1-27.2) |
| Moderate | 630 | 34.1 | (32.0-36.3) | 439 | 36.4 | (33.7-39.1) | 1069 | 35.0 | (33.3-36.7) |
| Severe | 499 | 27.0 | (25.0-29.1) | 286 | 23.7 | (21.4-26.2) | 785 | 25.7 | (24.2-27.3) |
| Very severe | 236 | 12.8 | (11.3-14.4) | 154 | 12.8 | (11.0-14.8) | 390 | 12.8 | (11.6-14.0) |
| Unsure | 15 | 0.8 | (0.5-1.3) | 13 | 1.1 | (0.6-1.8) | 28 | 0.9 | (0.6-1.3) |
| Place of exposure (excluding medical cause of exposure) | |||||||||
| Home | 856 | 49.9 | (47.5-52.2) | 408 | 34.3 | (31.6-37.0) | 1264 | 43.5 | (41.7-45.3) |
| Outside of home | 861 | 50.1 | (47.8-52.5) | 783 | 65.7 | (63.0-68.4) | 1644 | 56.5 | (54.7-58.3) |
| Treatment type | |||||||||
| None | 251 | 13.6 | (12.1-15.2) | 194 | 16.1 | (14.1-18.3) | 445 | 14.6 | (13.4-15.9) |
| Type 1 or 2 antihistamines | 1319 | 71.4 | (69.3-73.4) | 825 | 68.4 | (65.7-70.9) | 2144 | 70.2 | (68.6-71.8) |
| Type 1 antihistamines | 1288 | 69.7 | (67.6-71.8) | 810 | 67.1 | (64.4-69.7) | 2098 | 68.7 | (67.0-70.3) |
| Type 2 antihistamines | 211 | 11.4 | (10.1-13.0) | 137 | 11.4 | (9.7-13.3) | 348 | 11.4 | (10.3-12.6) |
| EPI autoinjector | 426 | 23.1 | (21.2-25.0) | 270 | 22.4 | (20.1-24.8) | 696 | 22.8 | (21.3-24.3) |
| EPI (IV) | 194 | 10.5 | (9.2-12.0) | 107 | 8.9 | (7.4-10.6) | 301 | 9.9 | (8.8-11.0) |
| Oral corticosteroids | 350 | 18.9 | (17.2-20.8) | 188 | 15.6 | (13.6-17.7) | 538 | 17.6 | (16.3-19.0) |
| Topical corticosteroids | 102 | 5.5 | (4.6-6.7) | 64 | 5.3 | (4.2-6.7) | 166 | 5.4 | (4.7-6.3) |
| Bronchodilator | 257 | 13.9 | (12.4-15.6) | 146 | 12.1 | (10.4-14.1) | 403 | 13.2 | (12.0-14.4) |
| IV fluids | 166 | 9.0 | (7.8-10.4) | 103 | 8.5 | (7.1-10.2) | 269 | 8.8 | (7.9-9.9) |
| Oxygen therapy | 80 | 4.3 | (3.5-5.4) | 51 | 4.2 | (3.2-5.5) | 131 | 4.3 | (3.6-5.1) |
| Atropine | 6 | 0.3 | (0.1-0.7) | 3 | 0.2 | (0.1-0.8) | 9 | 0.3 | (0.2-0.6) |
| Glucagon | 2 | 0.1 | (0.0-0.4) | 0 | 0.0 | (0.0-0.0) | 2 | 0.1 | (0.0-0.3) |
| Unsure | 34 | 1.8 | (1.3-2.6) | 24 | 2.0 | (1.3-2.9) | 58 | 1.9 | (1.5-2.4) |
| Other | 143 | 7.7 | (6.6-9.1) | 103 | 8.5 | (7.1-10.2) | 246 | 8.1 | (7.1-9.1) |
CI, Confidence interval; FARE, Food Allergy Research and Education; IV, intravenous.
All respondents were asked about their age and context at the time of their reaction (unintentional, intentional, medical care related, unsure). Additional information was captured by asking questions about processed or prepackaged food, self-perceived severity of reaction, place of exposure, and treatment type.
According to parent/guardian respondents, peanut was the most commonly reported food culprit (27.4%; CI: 25.4%-29.5%), whereas self-respondents were most often unsure of the source of their reaction (19.9%; CI: 17.7%-22.2%, P < .001). Among parent/guardians, 25.3% (95% CI: 23.4-27.3) described the child's most recent reaction as mild, whereas nearly 40% described the most recent reaction as severe (27.0%; CI: 25.0%-29.1%) or very severe (12.8%; CI: 11.3%-14.4%). Likewise, over one-fourth of self-respondents described their most recent reaction as mild (26.1%; CI: 23.7%-28.7%) and nearly 40% described the reaction as severe (23.7%; CI: 21.4%-26.2%) or very severe (12.8%; 95% CI: 11.0%-14.8%). Over half of parent/guardian respondents reported that the food culprit was a processed or prepackaged food (51.7%; CI: 49.4%-53.9%) compared with 45.7% (CI: 42.9%-48.5%, P < .001) of self-respondents. Approximately half (49.9%; CI: 47.5%-52.2%) of parent/guardian respondents reported that the reaction occurred at home compared with approximately two-thirds of self-respondents (65.7%; CI: 63.0%-68.4%, P < .001).
Intentional food-allergen exposures.
According to parent/guardian respondents, the most commonly reported reason for an intentional food-allergen exposure was that the child had never had a serious reaction before (50%; CI: 42.9%-57.1%) (Table III). This trend was sustained when the analyses were stratified by age. As seen in Table IV (self-respondents), the most common reason for intentional food-allergen exposure among adults was the decision to take the risk anyway (47.8%; CI: 38.7%-57.1%). This estimate was driven by the majority of self-respondents who reported reactions between ages 18 to 25 years (52.6%; CI: 30.9%-73.4%) and ages 26 to 65 years (48.8%; CI: 37.9%-59.7%). In addition, 26.5% (CI: 19.2%-35.5%) of self-respondents reported that they never had a serious past reaction and 19.5% (CI: 13.1%-27.9%) indicated that they did not believe the seriousness of their FA. Among parents/guardian respondents, 1.1% (CI: 0.3%-4.2%) reported bullying as the reason for the child's intentional exposure, whereas 1.8% (CI: 0.4%-6.9%) of self-respondents reported bullying as the reason for their own intentional exposure.
TABLE III.
Context of food allergen exposure among parent or guardian respondents
| Type of exposure | Overall (n = 188) | ≤5 y (n = 136) | 6-12 y (n = 44) | 13-17 y (n = 8) | 18-25 y (n = 0) | |||||
|---|---|---|---|---|---|---|---|---|---|---|
| Intentional | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI |
| Reason(s) for intentional exposure | ||||||||||
| Never had serious past reaction | 50.0 | (42.9-57.1) | 58.8 | (50.3-66.8) | 27.3 | (16.1-42.2) | 25.0 | (6.2-62.5) | 0.0 | (0.0-0.0) |
| Unaware of risk | 23.9 | (18.3-30.6) | 25.7 | (19.1-33.8) | 18.2 | (9.3-32.5) | 25.0 | (6.2-62.5) | 0.0 | (0.0-0.0) |
| Decided to take risk anyway | 9.6 | (6.1-14.7) | 5.9 | (3.0-11.4) | 20.5 | (11.0-35.0) | 12.5 | (1.7-54.1) | 0.0 | (0.0-0.0) |
| Did not believe seriousness of food allergy | 3.7 | (1.8-7.6) | 2.2 | (0.7-6.7) | 9.1 | (3.4-22.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) |
| Unaware that past reactions do not predict the severity of future reactions | 4.8 | (2.5-9.0) | 3.7 | (1.5-8.6) | 6.8 | (2.2-19.2) | 12.5 | (1.7-54.1) | 0.0 | (0.0-0.0) |
| Bullying | 1.1 | (0.3-4.2) | 0.0 | (0.0-0.0) | 4.5 | (1.1-16.6) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) |
| Other intentional reason(s) | ||||||||||
| Attempting to reintroduce food | 5.3 | (2.9-9.6) | 3.7 | (1.5-8.6) | 9.1 | (3.4-22.0) | 12.5 | (1.7-54.1) | 0.0 | (0.0-0.0) |
| Unspecified/missing | 3.7 | (1.8-7.6) | 2.2 | (0.7-6.7) | 9.1 | (3.4-22.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) |
| Overall (n = 1463) |
≤5 y n=737 |
6-12 y (n = 545) |
13-17 y (n = 172) |
18-25 y (n = 9) |
||||||
| Unintentional | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI |
| Reason(s) for unintentional exposure | ||||||||||
| Cross-contamination | 24.1 | (21.9-26.3) | 18.0 | (15.4-21.0) | 29.2 | (25.5-33.1) | 32.0 | (25.4-39.3) | 55.6 | (25.1-82.3) |
| Food allergen hidden in food and not listed on food label | 8.6 | (7.3-10.2) | 6.0 | (4.5-7.9) | 10.3 | (8.0-13.1) | 14.0 | (9.5-20.0) | 22.2 | (5.6-57.9) |
| Informed restaurant staff but still had reaction | 12.0 | (10.5-13.8) | 6.9 | (5.3-9.0) | 16.3 | (13.5-19.7) | 20.3 | (15.0-27.0) | 11.1 | (1.5-50.0) |
| Food label/menu was not clear or unavailable | 9.1 | (7.7-10.7) | 6.1 | (4.6-8.1) | 11.6 | (9.1-14.5) | 14.0 | (9.5-20.0) | 11.1 | (1.5-50.0) |
| Had eaten this food previously without reaction (new allergen suspected) | 9.0 | (7.6-10.5) | 9.9 | (7.9-12.3) | 7.3 | (5.4-9.9) | 10.5 | (6.7-16.0) | 0.0 | (0.0-0.0) |
| Did not read food label or menu | 8.6 | (7.3-10.2) | 5.2 | (3.8-7.0) | 12.3 | (9.8-15.3) | 12.2 | (8.1-18.0) | 0.0 | (0.0-0.0) |
| Child/adult grabbed food unknowingly | 6.0 | (4.9-7.4) | 7.2 | (5.5-9.3) | 4.8 | (3.3-6.9) | 3.5 | (1.6-7.6) | 33.3 | (11.1-66.7) |
| Did not inform restaurant staff about food allergy | 1.0 | (0.6-1.7) | 0.8 | (0.4-1.8) | 0.9 | (0.4-2.2) | 1.2 | (0.3-4.5) | 22.2 | (5.6-57.9) |
| Other unintentional reason(s) | ||||||||||
| Air exposure | 1.2 | (0.8-1.9) | 1.1 | (0.5-2.2) | 1.3 | (0.6-2.7) | 1.7 | (0.6-5.3) | 0.0 | (0.0-0.0) |
| Caregiver/relative mistake | 3.4 | (2.6-4.5) | 4.1 | (2.9-5.8) | 3.1 | (1.9-5.0) | 1.7 | (0.6-5.3) | 0.0 | (0.0-0.0) |
| First reaction/unknown allergy | 14.4 | (12.6-16.2) | 23.3 | (20.4-26.5) | 5.5 | (3.9-7.8) | 4.7 | (2.3-9.0) | 0.0 | (0.0-0.0) |
| Food service/preparation mistake | 1.6 | (1.0-2.4) | 0.8 | (0.4-1.8) | 2.2 | (1.3-3.8) | 2.9 | (1.2-6.8) | 0.0 | (0.0-0.0) |
| Forgot that food/medication contained allergen | 0.1 | (0.0-0.5) | 0.0 | (0.0-0.0) | 0.2 | (0.0-1.3) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) |
| Kissing | 0.6 | (0.3-1.2) | 1.1 | (0.5-2.2) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 11.1 | (1.5-50.0) |
| New ingredients in previously consumed food | 0.3 | (0.1-0.8) | 0.0 | (0.0-0.0) | 0.2 | (0.0-1.3) | 2.3 | (0.9-6.0) | 0.0 | (0.0-0.0) |
| Unconfirmed diagnosis/unaware of food allergy | 5.0 | (4.0-6.2) | 7.2 | (5.5-9.3) | 3.1 | (1.9-5.0) | 1.7 | (0.6-5.3) | 0.0 | (0.0-0.0) |
| Reaction to medication/vaccination | 0.2 | (0.1-0.6) | 0.4 | (0.1-1.3) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) |
| Skin contact | 3.1 | (2.3-4.1) | 1.9 | (1.1-3.2) | 4.8 | (3.3-6.9) | 2.9 | (1.2-6.8) | 0.0 | (0.0-0.0) |
| Unsure | 6.2 | (5.1-7.6) | 6.2 | (4.7-8.2) | 6.2 | (4.5-8.6) | 6.4 | (3.6-11.2) | 0.0 | (0.0-0.0) |
CI, Confidence interval.
Respondents were asked to include reasons for both intentional and unintentional food allergen exposure. Medical care-related exposures were excluded.
TABLE IV.
Context of food allergen exposure among self-respondents
| Type of exposure |
Overall (n = 113) |
≤5 y (n = 7) |
6-12 y (n = 0) |
13-17 y (n = 4) |
18-25 y (n = 19) |
26-65 y (n = 80) |
≥65 y (n = 3) |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Intentional | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI |
| Reason(s) for intentional exposure | ||||||||||||||
| Never had serious past reaction | 26.5 | (19.2-35.5) | 28.6 | (7.1-67.7) | 0.0 | (0.0-0.0) | 50.0 | (12.1-87.9) | 26.3 | (11.3-50.1) | 25.0 | (16.7-35.7) | 33.3 | (4.2-85.0) |
| Unaware of risk | 14.2 | (8.8-22.0) | 14.3 | (1.9-58.6) | 0.0 | (0.0-0.0) | 50.0 | (12.1-87.9) | 5.3 | (0.7-29.8) | 15.0 | (8.7-24.7) | 0.0 | (0.0-0.0) |
| Decided to take risk anyway | 47.8 | (38.7-57.1) | 28.6 | (7.1-67.7) | 0.0 | (0.0-0.0) | 25.0 | (3.3-76.7) | 52.6 | (30.9-73.4) | 48.8 | (37.9-59.7) | 66.7 | (15.0-95.8) |
| Did not believe seriousness of food allergy | 19.5 | (13.1-27.9) | 28.6 | (7.1-67.7) | 0.0 | (0.0-0.0) | 25.0 | (3.3-76.7) | 31.6 | (14.8-55.1) | 16.3 | (9.6-26.1) | 0.0 | (0.0-0.0) |
| Unaware that past reactions do not predict the severity of future reactions | 6.2 | (3.0-12.5) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 5.3 | (0.7-29.8) | 7.5 | (3.4-15.8) | 0.0 | (0.0-0.0) |
| Bullying | 1.8 | (0.4-6.9) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 2.5 | (0.6-9.6) | 0.0 | (0.0-0.0) |
| Other intentional reason(s) | ||||||||||||||
| Attempting to reintroduce food | 5.3 | (2.4-11.4) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 7.5 | (3.4-15.8) | 0.0 | (0.0-0.0) |
| Unspecified/missing | 0.9 | (0.1-6.1) | 14.3 | (1.9-58.6) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) |
| Overall (n = 1044) | ≤5 y (n = 55) | 6-12 y (n = 27) | 13-17 y (n = 48) | 18-25 y (n = 219) | 26-65 y (n = 651) | ≥65 y (n = 44) | ||||||||
| Unintentional | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI | % | 95% CI |
| Reason(s) for unintentional exposure | ||||||||||||||
| Cross-contamination | 32.2 | (29.4-35.1) | 30.9 | (20.2-44.2) | 40.7 | (24.2-59.7) | 39.6 | (26.9-53.9) | 38.8 | (32.6-45.4) | 29.2 | (25.8-32.8) | 31.8 | (19.8-46.8) |
| Food allergen hidden in food and not listed on food label | 21.5 | (19.1-24.1) | 14.5 | (7.4-26.5) | 11.1 | (3.6-29.4) | 22.9 | (13.2-36.8) | 23.7 | (18.6-29.8) | 22.3 | (19.2-25.6) | 11.4 | (4.8-24.6) |
| Informed restaurant staff but still had reaction | 16.6 | (14.4-19.0) | 16.4 | (8.7-28.6) | 18.5 | (7.9-37.5) | 16.7 | (8.6-30.0) | 20.5 | (15.7-26.4) | 14.4 | (11.9-17.4) | 27.3 | (16.2-42.2) |
| Food label/menu was not clear or unavailable | 18.6 | (16.3-21.1) | 18.2 | (10.1-30.6) | 18.5 | (7.9-37.5) | 27.1 | (16.4-41.3) | 20.5 | (15.7-26.4) | 17.4 | (14.6-20.5) | 18.2 | (9.4-32.4) |
| Had eaten this food previously without reaction (new allergen suspected) | 10.3 | (8.6-12.3) | 14.5 | (7.4-26.5) | 11.1 | (3.6-29.4) | 16.7 | (8.6-30.0) | 11.9 | (8.2-16.9) | 9.2 | (7.2-11.7) | 6.8 | (2.2-19.1) |
| Did not read food label or menu | 9.1 | (7.5-11.0) | 9.1 | (3.8-20.1) | 3.7 | (0.5-22.1) | 10.4 | (4.4-22.7) | 9.6 | (6.3-14.3) | 9.2 | (7.2-11.7) | 6.8 | (2.2-19.1) |
| Child/adult grabbed food unknowingly | 4.1 | (3.1-5.5) | 3.6 | (0.9-13.4) | 11.1 | (3.6-29.4) | 4.2 | (1.0-15.2) | 3.7 | (1.8-7.1) | 3.8 | (2.6-5.6) | 6.8 | (2.2-19.1) |
| Did not inform restaurant staff about food allergy | 6.2 | (4.9-7.9) | 1.8 | (0.3-11.8) | 3.7 | (0.5-22.1) | 10.4 | (4.4-22.7) | 6.8 | (4.2-11.1) | 6.6 | (4.9-8.8) | 0.0 | (0.0-0.0) |
| Other unintentional reason(s) | ||||||||||||||
| Air exposure | 3.4 | (2.5-4.7) | 1.8 | (0.3-11.8) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 2.3 | (1.0-5.4) | 4.1 | (2.9-6.0) | 6.8 | (2.2-19.1) |
| Caregiver/relative mistake | 1.1 | (0.7-2.0) | 5.5 | (1.8-15.6) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 2.3 | (1.0-5.4) | 0.6 | (0.2-1.6) | 0.0 | (0.0-0.0) |
| First reaction/unknown allergy | 3.5 | (2.6-4.9) | 7.3 | (2.8-17.8) | 11.1 | (3.6-29.4) | 0.0 | (0.0-0.0) | 2.3 | (1.0-5.4) | 3.7 | (2.5-5.4) | 2.3 | (0.3-14.5) |
| Food service/preparation mistake | 2.1 | (1.4-3.2) | 3.6 | (0.9-13.4) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 3.7 | (1.8-7.1) | 1.8 | (1.0-3.2) | 0.0 | (0.0-0.0) |
| Forgot that food/medication contained allergen | 0.2 | (0.0-0.8) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.5 | (0.1-3.2) | 0.2 | (0.0-1.1) | 0.0 | (0.0-0.0) |
| Kissing | 0.6 | (0.3-1.3) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 2.1 | (0.3-13.4) | 1.4 | (0.4-4.2) | 0.3 | (0.1-1.2) | 0.0 | (0.0-0.0) |
| New ingredients in previously consumed food | 0.3 | (0.1-0.9) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.5 | (0.1-3.2) | 0.2 | (0.0-1.1) | 2.3 | (0.3-14.5) |
| Unconfirmed diagnosis/unaware of food allergy | 1.1 | (0.6-1.9) | 0.0 | (0.0-0.0) | 3.7 | (0.5-22.1) | 0.0 | (0.0-0.0) | 0.9 | (0.2-3.6) | 1.1 | (0.5-2.2) | 2.3 | (0.3-14.5) |
| Reaction to medication/vaccination | 0.1 | (0.0-0.7) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.0 | (0.0-0.0) | 0.2 | (0.0-1.1) | 0.0 | (0.0-0.0) |
| Skin contact | 1.7 | (1.1-2.7) | 3.6 | (0.9-13.4) | 7.4 | (1.9-25.3) | 2.1 | (0.3-13.4) | 1.8 | (0.7-4.8) | 1.4 | (0.7-2.6) | 0.0 | (0.0-0.0) |
| Unsure | 5.7 | (4.5-7.3) | 7.3 | (2.8-17.8) | 0.0 | (0.0-0.0) | 2.1 | (0.3-13.4) | 4.1 | (2.2-7.7) | 6.5 | (4.8-8.6) | 9.1 | (3.5-21.9) |
CI, Confidence interval.
Respondents were asked to include reasons for both intentional and unintentional food allergen exposure. Medical care-related exposures were excluded.
Unintentional food-allergen exposures.
Cross-contamination was the most common reason for unintentional exposures in both groups of respondents. Among parent/guardian respondents, 24.1% (CI: 21.9%-26.3%) cited cross-contamination compared with 32.2% (CI: 29.4%-35.1%) of self-respondents. This trend was consistent across all age groups. Other commonly cited reasons for unintentional food-allergen exposure reported by parent/guardian respondents included exposure to an unknown allergen or first reaction (14.4%; CI: 12.6%-16.2%) and informing restaurant staff, but still had a reaction (12.0%; CI: 10.5%-13.8%). Furthermore, self-respondents report the food allergen hidden in food and not listed on food label (21.5%; CI: 19.1%-24.1%) and the food label/menu either not clear or unavailable (18.6%; CI: 16.3%-21.1%) as additional reasons for unintentional food allergen exposure.
Associations.
As indicated in Table E1 (available in this article's Online Repository at www.jaci-inpractice.org ), there were several significant predictors of having 1 or more food-related allergic reactions per year. Food-allergic patients living in the northeast were significantly less likely to report having 1 or more reactions per year, in comparison with those living in the west (odds ratio [OR]: 0.71; CI: 0.53-0.94). Patients with peanut (OR: 0.58; CI: 0.47-0.73) and treenut (OR: 0.77; CI: 0.63-0.95) were significantly less likely to report 1 or more reactions per year, in comparison with patients with other types of food allergies. Respondents with egg (OR: 1.71; CI: 1.37-2.14), milk (OR: 1.95; CI: 1.56-2.44), fin fish (OR: 1.54; 95% CI: 1.09-2.18), wheat (OR: 1.84; CI: 1.35-2.49), or soy (OR: 1.76; CI: 1.35-2.31) were all significantly more likely to report having 1 or more reactions per year, in comparison with patients with other types of food allergies. Finally, respondents whose most recent reaction was severe (OR: 0.65; CI: 0.46-0.77) or very severe (OR: 0.60; CI: 0.44-0.82) were less likely to report having 1 or more reactions per year, in comparison with respondents with mild reactions. We also modeled the probability of having an intentional food-allergen exposure. Only reactions stemming from treenuts were associated with a lower odds of an intentional exposure compared with peanut (OR 0.5; CI: 0.3-0.9). All other predictors (ie, type of respondent, gender, race, ethnicity, type of food allergen exposure) were not significantly associated with this outcome (P > .05).
Discussion
Utilizing data from the largest national online FA patient registry, we demonstrated that on average, nearly two-thirds of adults and nearly half of children experienced 1 or more food-related allergic reactions per year. In addition, we found that although the majority of reactions were unintentional, 1 in 10 respondents reported an intentional food allergen exposure.
Given that our estimates of food-related allergic reaction frequency include reactions that have resulted in an ED visit or hospitalization, as well as those that have been resolved at home, our estimates are substantially higher than previous studies focused only on reactions resulting in clinical care. For example, in a large population-based survey of US households, approximately 8.6% of adults and 19.0% of children reported a food-related allergic reaction resulting in an ED visit within the past year.2,3 Other studies have focused solely on anaphylaxis, suggesting the frequency of food-induced anaphylaxis resulting in ED visits and/or hospitalizations in children and adolescents is on the rise. 789 Although studies based on this methodology may capture the frequency of severe allergic reactions, they exclude milder allergic reactions that may have resolved without the need for clinical attention.
In contrast, our frequency estimates more closely align with the few epidemiological studies that have collected data on reactions both inside and outside of clinical care. For example, a 2018 prospective cohort study found that nearly half of adult patients with physician-confirmed FA experienced an unintentional food-related allergic reaction over the 1-year study period.10 An older study from 2001 that surveyed 132 parents of food-allergic preschool-aged children found that 39% of these children had at least 1 food-related allergic reaction while in school within the past 2 years.11 A more recent study of 512 infants with milk or egg allergy showed that 52.5% reported more than 1 reaction within a median follow-up period of 35.5 months.6
We found that most food-related allergic reactions were due to unintentional food allergen exposures, and the most common reason for exposure was cross-contamination. These data align with numerous studies that have established cross-contamination as a serious risk for food-allergic patients.12-15 Given that nearly half of reactions in our sample were the result of eating prepackaged/processed foods, 1 plausible explanation for cross-contamination in the current study is misreading and/or misinterpretation of food ingredients, food labels, and/or packaging. Although the Food Allergen Labeling and Consumer Protection Act mandates that companies include the presence of the top 8 allergens on food labels, precautionary allergy statements such as those including the verbiage “may contain” often lead to uncertainty among consumers with FA.7,16 Although the current survey did not probe respondents about food labeling issues as they are related to the specific reaction being described, future research should aim to make this link. Clearly, despite current policies on food labeling, there is still confusion for food allergic consumers and avoidance of these foods remains difficult.
With respect to intentional food-allergen exposure, we found that among both children and adults, approximately 1 in 10 had an intentional food-allergen exposure that led to a reaction. This finding aligns with data from a follow-up to the aforementioned 2012 prospective study, which showed that among 512 infants with egg or milk allergy, 8% had intentional food-allergen exposure.17 Moreover, we showed that the most common reason behind intentional food allergen exposure among children was that the child had never experienced a serious food-related allergic reaction in the past. Similarly, the 2012 infant cohort study also demonstrated that a third of families reported the reason for intentional exposure was that the child had no severe reaction history.17
Our estimate of intentional exposures among adults is lower than estimates from previous research on FA-related risk-taking behaviors, the majority of which have studied food-allergic adolescents and young adults.18,19 We attribute this discrepancy to the demographics of the online registry, which represents a well-educated, socially supported, and high-income population that may be more averse to risk-taking behaviors in comparison with the general population. We also showed that the most common motivation for intentional exposure among adults was the decision to take the risk anyway, despite knowing the dangers. This finding aligns with previous literature on risk-taking behavior in food-allergic adolescents and young adults. Despite that the risk for fatal anaphylaxis is highest among these age groups, they continue to report risky behavior with respect to food allergies.20 Providing more education and enhanced social support networks for adolescents and young adults with and without FA may help to alleviate risk-taking behavior.
The current study illustrates that 3 in 5 of the respondent's most recent food-related allergic reactions were moderate to severe, and nearly 1 in 4 most recent reactions required treatment using an EAI. These findings concur with recent population-based studies that demonstrated that among adults, over half had ever experienced a severe food-related allergic reaction and among children, nearly half were considered to have a severe FA.2 The high rate of use of epinephrine in our study suggests the need to address the cause of food-related allergic reactions, particularly those that are severe, across all age groups.
Although the present study highlights important data on the characterization and context of food-related allergic reactions, it has limitations. First, the convenience sample had a limited racial/ethnic and socioeconomic distribution; most respondents were white, non-Hispanic/Latinx, and affluent. Second, survey access is generally limited to those with internet access. These findings, therefore, may not be generalizable to the broader food-allergic population. Third, given that the FARE Registry is a voluntary, nonincentivized survey, there may be selection bias because respondents may be highly motivated with respect to FA management and may have more severe FA. Fourth, the survey did not collect information on any other food-related allergic reaction besides the most recent, which may not accurately represent the self-perceived severity or frequency of FA. Furthermore, because the participants reported reactions that did not result in ED or physician visits, we cannot be certain about the accuracy of the reported reaction. Finally, the survey relied on self-report of information, which increases the risk of both recall and information bias. Although we recognize its limitations, this study contributes important and much needed data to the area of FA.
The present study finds that food-related allergic reactions are occurring frequently and suggests the need for standardized methodology to identify and quantify food-related allergic reaction frequency and context. Additional research is necessary to further clarify the motivations behind intentional food-allergen exposure among both children and adults of diverse racial/ethnic and socioeconomic groups.
Supplementary Material
What is already known about this topic? Evidence from small clinical samples suggests that unintentional reactions are common among children and adults living with food allergy. Cross-contamination is a common cause of reactions.
What does this article add to our knowledge? In a large national patient registry, half of patients had 1 or more reactions per year. Although most reactions were due to unintentional exposure, 1 in 10 reactions were due to intentional exposure.
How does this study impact current management guidelines? Although providing patient education around food allergen avoidance is a recommended part of patient care, exposure avoidance—both intentional and unintentional— remains challenging. Current guidelines should take into account motivations behind both intentional and unintentional exposures.
Acknowledgments
The authors would like to extend their gratitude to Dana Ward for her expertise and contributions to this research.
This work was supported by Food Allergy Research and Education (FARE). Conflicts of interest: R. Gupta receives research grant support from the National Institutes of Health (NIH), Food Allergy Research and Education (FARE), Stanford Sean N. Parker Center for Allergy Research, UnitedHealth Group, Thermo Fisher Scientific, Genentech, and the National Confectioners Association (NCA); and has served as a medical consultant/advisor for Aimmune Therapeutics, Genentech, Before Brands, Kaléo, DBV Technologies, ICER, DOTS Technology, and FARE. L. Bilaver receives research grant support from the NIH, Thermo Fisher Scientific, FARE, Genentech, NCA, and Before Brands Inc. The rest of the authors declare that they have no relevant conflicts of interest. Research reported in this publication was supported by the National Institute on Minority Health and Health Disparities of the National Institutes of Health under Award Number T37MD014248. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.
Abbreviations used
- CI
Confidence interval
- EAI
Epinephrine autoinjector
- ED
Emergency department FA- Food allergy
- FARE
Food Allergy Research and Education
- QR
Interquartile range
- OR
Odds ratio
References
- 1.Gupta RS, Springston EE, Warrier MR, Smith B, Kumar R, Pongracic J, et al. The prevalence, severity, and distribution of childhood food allergy in the United States. Pediatrics 2011;128:e9–17. [DOI] [PubMed] [Google Scholar]
- 2.Gupta RS, Warren CM, Smith BM, Jiang J, Blumenstock JA, Davis MM, et al. Prevalence and severity of food allergies among US adults. JAMA Netw Open 2019;2:e185630. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.Gupta RS, Warren CM, Smith BM, Blumenstock JA, Jiang J, Davis MM, et al. The public health impact of parent-reported childhood food allergies in the United States. Pediatrics 2018;142:e20181235. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Bilaver LA, Chadha AS, Doshi P, O’Dwyer L, Gupta RS. Economic burden of food allergy: a systematic review. Ann Allergy Asthma Immunol 2019;122: 373–380.e1. [DOI] [PubMed] [Google Scholar]
- 5.Versluis A, Knulst AC, Kruizinga AG, Michelsen A, Houben GF, Baumert JL, et al. Frequency, severity and causes of unexpected allergic reactions to food: a systematic literature review. Clin Exp Allergy 2015;45:347–67. [DOI] [PubMed] [Google Scholar]
- 6.Fleischer DM, Perry TT, Atkins D, Wood RA, Burks AW, Jones SM, et al. Allergic reactions to foods in preschool-aged children in a prospective observational food allergy study. Pediatrics 2012;130:e25–32. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Lin RY, Anderson AS, Shah SN, Nurruzzaman F. Increasing anaphylaxis hospitalizations in the first 2 decades of life: New York State, 1990-2006. Ann Allergy Asthma Immunol 2008;101:387–93. [DOI] [PubMed] [Google Scholar]
- 8.Clark S, Espinola J, Rudders SA, Banerji A, Camargo CA Jr. Frequency of US emergency department visits for food-related acute allergic reactions. J Allergy Clin Immunol 2011;127:682–3. [DOI] [PubMed] [Google Scholar]
- 9.Hochstadter E, Clarke A, De Schryver S, LaVieille S, Alizadehfar R, Joseph L, et al. Increasing visits for anaphylaxis and the benefits of early epinephrine administration: a 4-year study at a pediatric emergency department in Montreal, Canada. J Allergy Clin Immunol 2016;137:1888–1890.e4. [DOI] [PubMed] [Google Scholar]
- 10.Blom WM, Michelsen-Huisman AD, van Os-Medendorp H, van Duijn G, de Zeeuw-Brouwer ML, Versluis A, et al. Accidental food allergy reactions: products and undeclared ingredients. J Allergy Clin Immunol 2018;142:865–75. [DOI] [PubMed] [Google Scholar]
- 11.Nowak-Wegrzyn A, Conover-Walker MK, Wood RA. Food-allergic reactions in schools and preschools. Arch Pediatr Adolesc Med 2001;155:790–5. [DOI] [PubMed] [Google Scholar]
- 12.Taylor SL, Baumert JL. Cross-contamination of foods and implications for food allergic patients. Curr Allergy Asthma Rep 2010;10:265–70. [DOI] [PubMed] [Google Scholar]
- 13.Alldrick A Assessment of risk from food allergens cross-contamination. Clin Transl Allergy 2011;1(Suppl 1):S40. [Google Scholar]
- 14.Young I, Thaivalappil A. A systematic review and meta-regression of the knowledge, practices, and training of restaurant and food service personnel toward food allergies and Celiac disease. PLoS One 2018;13:e0203496. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Zurzolo GA, Mathai ML, Koplin JJ, Allen KJ. Hidden allergens in foods and implications for labelling and clinical care of food allergic patients. Curr Allergy Asthma Rep 2012;12:292–6. [DOI] [PubMed] [Google Scholar]
- 16.DunnGalvin A, Chan CH, Crevel R, Grimshaw K, Poms R, Schnadt S, et al. Precautionary allergen labelling: perspectives from key stakeholder groups. Allergy 2015;70:1039–51. [DOI] [PubMed] [Google Scholar]
- 17.Mudd KE, Ellingson J, Mayfield P, Talarico LP, Kamilaris JS, Sicherer SH. Circumstances of medically unadvised purposeful exposure to food allergens in an observational study (Consortium of Food Allergy Research, COFAR). J Allergy Clin Immunol 2013;131:AB125. [Google Scholar]
- 18.Greenhawt MJ, Singer AM, Baptist AP. Food allergy and food allergy attitudes among college students. J Allergy Clin Immunol 2009;124:323–7. [DOI] [PubMed] [Google Scholar]
- 19.Sampson MA, Munoz-Furlong A, Sicherer SH. Risk-taking and coping strategies of adolescents and young adults with food allergy. J Allergy Clin Immunol 2006;117:1440–5. [DOI] [PubMed] [Google Scholar]
- 20.Bock SA, Munoz-Furlong A, Sampson HA. Further fatalities caused by anaphylactic reactions to food, 2001-2006. J Allergy Clin Immunol 2007;119:1016–8. [DOI] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.