Julie Wang, MD, Michael Young, MD, Anna Nowak-Wegrzyn, MD
Jul 18, 2013
A 7-year-old girl with known peanut allergy was given 1 peanut on the playground during a school recess break by another child who was unaware of her severe allergies. Shortly after eating the peanut, she felt unwell and asked the teacher for help.
We will use the tragic example of the fatal outcome of peanut anaphylaxis in a child to discuss several important issues, with special emphasis on managing food allergies at school.
Food allergies are an important public health concern, and their prevalence is increasing. Recent data indicate that 5.1% of children 0-17 years of age were affected by food allergies in 2009-2011, an increase from 3.4% in 1997-1999.
Food allergies trigger allergic reactions that can range from mild to severe, including life-threatening anaphylaxis. In fact, food was the most common trigger of anaphylaxis in a population-based incidence study. In another study examining emergency department visits and admissions for food-induced anaphylaxis between 2001 and 2006, a significant increase in both was observed, demonstrating that food-induced anaphylaxis continues to be an important issue.
Deaths as a result of anaphylaxis do occur, and approximately 500-1000 fatalities per year are reported in the United States. Up to 30% of fatal anaphylaxis cases are triggered by food allergens. Although over 90% of these are associated with nut (peanut or tree nuts) exposures in the United States, it is important to note that allergic reactions to any foods have the potential to cause severe allergic reactions and anaphylaxis. Furthermore, the severity of allergic reactions to foods cannot be predicted by history or by either skin prick or allergen-specific IgE level testing.
For some, the first presenting sign of an allergy is anaphylaxis. Nearly 25% children who received epinephrine to treat severe allergic reactions in schools had no history of life-threatening allergy, and approximately 20% of reactions occurring in school settings are due to first exposure to the food allergen.
Anaphylaxis is a serious allergic reaction that is rapid in onset and may cause death. The signs and symptoms can be varied and can affect any organ system. Until 2006, there was no consensus definition for anaphylaxis, resulting in significant variations in and underrecognition of identification and treatment of anaphylaxis -- not only by medical professionals, but also by patients and their caretakers.[10,11] Because there can be significant variability in the presentation of anaphylaxis, an expert panel proposed criteria for diagnosing anaphylaxis.
Table. Clinical Criteria for Diagnosing Anaphylaxis
BP = blood pressure; PEF = peak expiratory flow. Data from Sampson HA, et al. Ann Emerg Med. 2006;47:373-380.
Symptoms affecting the skin are commonly seen in allergic reactions (up to 80% of cases). Cutaneous symptoms appearing in conjunction with respiratory or cardiovascular symptoms fulfill the criteria for anaphylaxis.
As seen in the diagnostic criteria, the clinical spectrum of anaphylaxis is wide. Although skin symptoms are seen in the majority of allergic reactions, up to 20% of cases of anaphylaxis can present without skin findings. Thus, the absence of dermatologic symptoms does not rule out anaphylaxis.[2,12] In these cases, a history of allergy and likely exposure to a food allergen, along with symptoms affecting at least 2 organ systems (gastrointestinal, respiratory, or cardiovascular), establishes the diagnosis of anaphylaxis.
In rare cases, isolated hypotension has been reported to be the primary symptom of anaphylaxis. Therefore, if hypotension is found in a patient who has known exposure to a food allergen, treatment for anaphylaxis should be initiated.
Although the onset of anaphylaxis can be variable, ranging from within seconds to a few hours after exposure to the causal food allergen, the majority of reactions manifest within 1 hour of exposure. The time course for anaphylaxis can be uniphasic, biphasic, or protracted. Most reactions are uniphasic, with symptoms resolving quickly after treatment. Up to 20% are biphasic, in which recurrence of symptoms is seen after resolution of the initial symptoms without reexposure to the allergen. The biphasic response is often variable in terms of severity and most often occurs within 8 hours of the initial symptoms. Protracted anaphylaxis from food allergy is less commonly seen.
Several risk factors have been identified for food-induced anaphylaxis. Approximately one third of persons who have had anaphylaxis have comorbid asthma, and the majority of those with fatal or near-fatal anaphylaxis to foods had underlying asthma.[16,17] Patients with asthma of any severity are at increased risk for severe food allergic reactions.
Although any food allergen can trigger anaphylaxis, the majority of severe food reactions are triggered by peanuts and tree nuts. In a report of fatal anaphylaxis cases, over one half were triggered by nuts. In a recent study of children with food allergy in the United States, anaphylaxis was most often associated with multiple food allergies or having allergies to peanuts, tree nuts, or shellfish.
Adolescents and young adults are particularly at risk owing to their increased risk-taking behaviors, which can include ingestion of unsafe foods and not carrying emergency medications. In a survey of college students, only 39.7% reported always avoiding the foods to which they were allergic; 21% reported that they had self-injectable epinephrine, but only 6.6% reported always carrying the device. Additional risk-taking behaviors include alcohol and drug consumption, which can compromise an individual's ability to evaluate the safety of foods and impair self-recognition of signs and symptoms of allergic reaction, leading to delays in initiating appropriate treatment.
Exercise and alcohol, as well as such medications as aspirin, beta-blockers, angiotensin-converting enzyme inhibitors, monoamine oxidase inhibitors, tricyclic antidepressants, and antacids, may independently increase the severity of anaphylactic reactions or diminish the efficacy of epinephrine.[6,20]
The diagnosis of food-induced anaphylaxis relies on the clinical picture and recognition of signs and symptoms, because there is currently no rapid, reliable test to establish the diagnosis. A detailed history should include the time of onset of symptoms after the allergen exposure, evolution of signs and symptoms, presence of augmenting factors (eg, medications, alcohol, exercise), and treatments given before presenting for medical attention. Additional questions should include comorbid medical problems, prior experiences with the triggering food, and history of anaphylaxis.
Laboratory tests, such as serum histamine and serum tryptase, have poor diagnostic value for food-induced anaphylaxis because they have low sensitivity and specificity. Elevations of histamine can be seen in food-induced anaphylaxis; however, samples require special handling and increases in histamine level are transient (15-60 minutes) and therefore are often missed. Elevations in serum tryptase are often not seen in food-induced anaphylaxis. Novel biomarkers, including platelet-activating factor acetylhydrolase, are currently being investigated.
The teacher walked the child to the nurse's office. By the time they arrived, the child was struggling to breathe.
Epinephrine is the treatment of choice for anaphylaxis. The reversal of anaphylaxis results from the pharmacologic effects of epinephrine:
Alpha-1-adrenergic effects that lead to vasoconstriction, increased vascular resistance, and decreased mucosal edema;
Beta-1-adrenergic effects that increase inotropy and chronotropy; and
Beta-2 adrenergic effects mediating bronchodilation.
Stimulation of the beta-2-adrenergic receptor may also downregulate mast cell activation and inhibit further release of the mast cell mediators.
There are no absolute contraindications to the use of epinephrine in the setting of anaphylaxis. The recommended dose is 0.01 mg/kg, up to 0.3 mg for children and 0.5 mg for adults, administered intramuscularly in the thigh. The preferred location for injection is the thigh (vastus lateralis muscle) because compared with subcutaneous or intramuscular injection into the deltoid muscle of the arm, the time to peak concentration of epinephrine in serum is shorter and the peak concentration is higher. Epinephrine should not be administered intravenously for the treatment of anaphylaxis except in severe hypotension, in which case it should be administered as a titrated vasopressor drip.
Any patient with a history of anaphylaxis or allergy to peanut, tree nuts, fish, or shellfish or with both food allergy and asthma should be prescribed an epinephrine autoinjector for emergencies. Epinephrine autoinjectors are available in the community setting, with prefilled doses of 0.15 mg for persons weighing < 55 lb and 0.3 mL for those weighing 55 lb or more. Several autoinjectors are currently on the market (Adrenaclick®, Auvi-Q™, EpiPen®). Although instructions appear on the autoinjectors themselves, it is important to ensure that patients and caregivers are familiar with the use of these autoinjectors to minimize delay in administration or incorrect use (eg, accidental injection in the finger or self-injection when a caregiver is administering the medication).
Up to 20% of children with food-induced anaphylaxis require 2 doses of epinephrine to adequately treat symptoms.[24,25] It is therefore advisable that patients have 2 doses available at all times. The second dose of epinephrine is indicated when there is no improvement or symptoms recur or increase in the 5-10 minutes after the first dose.
Epinephrine administration should be immediately followed by a 911 call to activate the emergency medical system for transport to the nearest hospital for further medical treatment and to observe for biphasic anaphylaxis, which can occur in up to 20% of anaphylaxis cases. Epinephrine administration should not be delayed while help is being sought.
The health aide did not have an epinephrine autoinjector with the child's name on it and was unable to administer the drug. Although 911 was called immediately, by the time the ambulance arrived, the child was in cardiac arrest. Despite cardiopulmonary resuscitation by school and ambulance staff and rapid transport to the hospital by the ambulance crew, the child was pronounced dead on arrival.
Adjunctive treatments include placing the patient supine with legs elevated, if tolerable. This enhances cardiac preload in cases of anaphylactic shock. To prevent orthostatic hypotension, rapidly standing or sitting the hypotensive patient up is contraindicated. In younger children with significant respiratory distress or patients with ongoing emesis, the recumbent position may increase their distress, and the position of comfort would be preferable.
Additional treatments include oxygen and intravenous fluids. In patients with significant bronchoconstriction and wheezing, a nebulized bronchodilator (eg, albuterol) may be administered, after intramuscular epinephrine.
Antihistamines are considered second-line treatment for anaphylaxis because these medications only treat cutaneous symptoms and do not have a significant effect on cardiovascular symptoms.[28,29] A few studies have examined the role of corticosteroids in anaphylaxis treatment with mixed results. Whereas one study suggested that corticosteroids may minimize or prevent a late-phase response, another found no beneficial effects.
It is unclear why an epinephrine autoinjector was not provided to the school by the child's family. It was illegal for the health aide to use another child's epinephrine autoinjector for the treatment of this child's peanut anaphylaxis.
Successful management of food-allergic children in the school setting requires collaboration among the child's family, primary care provider, school nurse, and school staff. The family is responsible for alerting the school to the child's food allergies; providing emergency medications, such as epinephrine autoinjectors; and submitting a written IHP that addresses prevention of unintentional exposures of food allergen, as well as an emergency action plan (EAP) for the treatment of acute allergic reactions and management of anaphylaxis.[8,32,33] The IHP is formulated by the family, healthcare provider, and school nurse with input from school staff, including administrators, teachers, transportation, and food services.
The family may elect to provide safe snacks for the child. The child is taught the principles of safe practices for food allergies, such as eating only designated foods, hand-washing before and after meals, and no food sharing. Food allergen avoidance strategies are age-dependent and relate to the child's emotional and cognitive maturity, attention span, communication and social interaction skills, and knowledge base. As the child ages and matures, more responsibility can be transitioned from the school to the student, including carrying and administering epinephrine autoinjectors.
The school is responsible for implementing the IHP and EAP and educating teachers and school staff in the recognition of the signs and symptoms of allergic reactions and anaphylaxis, usually under the supervision of the school nurse. The school nurse is also responsible for instructing designated school staff, needed in the absence of the nurse, in the administration of epinephrine autoinjectors. The school is responsible for providing safe foods for the child and a safe environment in which food is consumed; educating students and staff in the principles of label reading and issues of cross-contact; and decreasing the use of foods in classroom settings, such as parties and celebrations, arts and crafts projects, and counting exercises.
In a Massachusetts study, 46% of anaphylaxis incidents occurred in the classroom, compared with 9% in the cafeteria. In students registered in the US Peanut and Tree Nut Allergy Registry, 79% of food allergic reactions occurred in the classroom compared with just 12% in the cafeteria.
A 2004 study demonstrated the effectiveness of soap and water and routine cleaning agents in the removal of the major peanut allergen, Ara h 1, from hands and table surfaces, concluding that it was relatively easily cleaned with common agents and did not appear to be widely distributed in schools. Using these principles, schools can maximize the safety of food-allergic children by requiring hand-washing before and after meals and instituting the option of allergen-safe tables or areas that have received more careful cleaning and monitoring. To avoid creating an atmosphere of social isolation, friends with safe lunches should be allowed seating in these allergen-safe areas.
Finally, schools need to recognize that food-allergic children are often the victims of bullying. A recent study found 45.4% of food-allergic children reported being bullied, and 31.5% reported being bullied specifically because of their food allergy. Furthermore, only 52% of parents knew that their child was being bullied, so schools need to be especially vigilant in efforts to identify and promptly address any instances of bullying.
In the United States, children with the diagnosis of anaphylaxis are protected by the Americans With Disabilities Act of 1990, which prohibits educational institutions from discriminating against children on the basis of their disability and guarantees food-allergic children a free, appropriate education.[8,38] When families are unable to resolve issues related to food allergy management plans with their schools, legal recourse is provided by Section 504 of the Rehabilitation Act of 1973. For most situations, 504 plans are generally unnecessary.
For food-allergic children participating in free snack and lunch programs, federal regulations provide appropriate substitute foods if the school has received documentation of the specific food allergies and dietary recommendations from the child's healthcare provider. In 2011, the United States enacted the Food Allergy and Anaphylaxis Management Act, which requires the Department of Health and Human Services to develop and make available to all schools a voluntary set of guidelines for the management of food allergies and anaphylaxis and to provide incentive grants to schools to implement these policies.
The first episode of peanut allergy can occur in the school setting. In Massachusetts, 25% of anaphylactic reactions occur in individuals (including students and school staff) with no history of allergic reactions or anaphylaxis. Schools need to be prepared to diagnose and treat both students and staff with no previous history or known diagnosis of allergy and anaphylaxis.
Recognizing the potential for this scenario, many, but not all, schools have on hand unassigned "stock" epinephrine autoinjectors. There is some controversy related to liability issues of prescribing and administering unassigned epinephrine. The School Access to Emergency Epinephrine Act was introduced in Congress in 2011 to allow schools to have unassigned stock doses of epinephrine available to treat previously undiagnosed students or staff experiencing anaphylaxis, but this legislation is still pending. Other initiatives are under way to pass similar legislation on the state level.
Foods are the most common cause of anaphylaxis outside of the hospital setting in children and adults.
Any food can trigger anaphylaxis, but the majority of severe anaphylaxis episodes are triggered by nuts and seafood.
Prior reaction severity does not predict future reaction severity.
Up to 20% of cases of severe food-induced anaphylaxis may manifest without cutaneous symptoms
Epinephrine is the treatment of choice for anaphylaxis. There are no absolute contraindications to the use of epinephrine in cases of anaphylaxis.
The major risk for near-fatal and fatal anaphylaxis is delayed or lack of timely administration of epinephrine.
25% of anaphylaxis cases in school settings occur in individuals (students and staff) who have no previous diagnosis of allergy or anaphylaxis.
Any student with history of anaphylaxis or with allergy to peanut, tree nuts, fish, or shellfish or with food allergy and asthma should be prescribed an epinephrine autoinjector and given an individual emergency treatment plan for school.
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