Exposures to Peanuts

Inadvertent exposures in children with peanut allergy

This is an interesting article. This theme has appeared in the literature previously, here it is done on a much grander scale with over 1000 children in the study.

For those families/patients who start on this scary journey of peanut allergy an article like this gives an overall perspective regarding what could and what did happen to children with known peanut allergy. It is a nice survey of the troubles experienced. My feeling is that many families will have some reassurance regarding the diagnosis of peanut allergy after reviewing this publication. Other families may see similar risks and work to help avoid them.

The study is from Canada- yes they do eat peanut products there so the comparison is valid. The article recently appeared in the journal Pediatric Allergy and Immunology. The lead author was Nha Uyen Nguyen-Luu. The study was internally supported and funded. The lead author is in an allergy training program.

Overall the article is very interesting. It highlights a common problem of exposure and it gives a nice picture regarding some of the nuances of peanut exposure. For the readers who struggle with peanut allergy and their children with peanut allergy, this report may be also be an eye-opener.

As background it has been shown that accidental exposure to peanuts occurs between 3-75% of the peanut allergic population (US and UK studies).

Purpose This was an extension of an earlier study on children across Canada with peanut allergic children. This study looks at the incidence of accidental exposures to peanut, the severity of reactions due to those exposures, how the reactions were managed, and it looks at what may predict an accidental exposure.


Patient Selection: There were three sources used to identify children with peanut allergy; Montreal Children’s Hospital Allergy Clinics, advocacy organizations for food allergic patients, and organizations that provide products to allergic individuals.

Diagnostic Criteria:

  • A convincing history of a reaction and a positive skin test or a peanut specific IgE >0.35 kU/L
  • No/Uncertain history of a reaction and either a positive skin test, a peanut specific IgE >15 kU/L, or a positive peanut challenge


                Patient Characteristics: There were 1,411 participants. From this number, 854 were recruited between the years 2000 to 2009. Overall (using the entire group) the average age when the peanut allergy was diagnosed was 2 years. Over 60% were boys. Over 88% had at least one other allergic condition and just over half had another food allergy. There were 231 children who had no or an uncertain history of a            peanut reaction.

                The peanut reaction histories varied;

  •  No reaction 13.5% (but had a positive peanut test)
  •  Mild reaction- 22.2%
  •  Moderate reaction-49.8%
  •  Severe reaction- 14.5%

                Rate, location, and management of accidental exposures: There were 266 accidental exposures in 221 children. Another way to look at this was that in 2227 patient-years, the annual incidence of an accidental exposure was 11.9%.

                Location of the accidental exposures-

  •  The child’s home – 39.5%
  •  Home of a relative/friend – 16.5%
  •  Restaurant – 10.9%
  •  School – 6.4%
  •  School with peanut prohibition – 4.5%
  •  Day care – 3.8%
  •  Unknown/Other places – 22.9%

                Most of the children (87.2%) attended schools that prohibited peanuts.

                Nature of the accidental exposure:

  • Oral ingestion – 174
  • Skin contact – 65
  • Inhalation – 13
  • Unknown – 14

                Management of the exposures:


Type of Reaction No Treatment Given (%)
Mild 78 (32.1%)
Moderate 145 (19.3%)
Severe 43 (4.7%)

                                46.5% of the severe reactions were treated at home

                                21.3% of moderate and severe reactions got epinephrine

                                62.8% of the severe reactions did not get epinephrine

                Severity of initial reaction vs. accidental exposure:

                                Types of reactions with the accidental exposures

  •  Mild – 26.7%
  •  Moderate – 44%
  •  Severe – 17.3%

There were 32 children (12%) who did not have a previous peanut exposure and experienced a reaction with an accidental exposure. 234 children with accidental exposures  had a previous peanut reaction.

                                Comparing the accidental exposure reaction to the initial reaction;

  • Accidental exposure more severe than the initial reaction – 23.5%
  • Accidental exposure was less severe than the initial reaction – 23.1%
  • Accidental exposure and initial exposure reactions were the same –  53.4%

                Predictors of accidental exposure:  Children who were 13 years of age or older at the time of entry into the study and those                         children who had a servere previous reaction to peanut had an increased risk of an accidental exposure.                                           

                The longer the peanut allergy diagnosis was known the risk of an accidental exposure decreased.


                This is the largest study published on the rate and predictors of accidental peanut exposures.  In these Canadian children, the annual rate of accidental exposure to peanuts was 11.9% of the children. There was also a decrease in the rate of exposures in those children who had the diagnosis of peanut allergy the longest. This was thought to be due to increased awareness and the development of avoidance strategies over time. More accidental exposures to peanut occur immediately after the diagnosis is made. Education about avoidance is critical during this interval.

                This rate of accidental exposure to peanut in the peanut allergic population is similar to what has been previously published in 2006 and is much lower than the rates of exposure published in earlier studies (50% and 60%).

                Just over 1/3 accidental exposures happened in the child’s home. Accidental exposures also occurred in ‘peanut-free’ schools.

                A previous study by these authors showed that 98.5% of the peanut allergic group was prescribed an epinephrine auto-injector, however moderate and severe reactions with the accidental exposure were not handled properly. In this study, 78.8% of the moderate and severe reactions to the accidental exposures were not treated with epinephrine. This included 45.5% of the reactions that were treated in a medical facility. A delay in the use of the epinephrine could result in a fatality. The point was made that it is crucial for parents and healthcare providers be better educated about the management of anaphylaxis.

Reviewer’s comments

                This is a very valuable contribution for families and for healthcare providers. When a family is told that the child has a peanut allergy, they embark on a very scary journey. The family may not have had any experience with a child with a food allergy. They may not know anyone with a peanut allergy.  They are told by healthcare professionals that the next exposure will be worse. They may have or not have an epinephrine auto-injector. They may not have been told how to use it, when to use it, why to use it, and what should be done once the injector is used. This website has a story shared by a mother who used an auto-injector for the first time.

                The family may have been told that this is a life-long food allergy. That the child has to sit at a peanut-free table and they need to closely watch what the child eats. This is a considerable burden. Families want to know what the wider experience with accidental exposures is. How do others do with this diagnosis? What might be in store for them? Can they be reassured by a report of a wider experience of children? Can they remedy the mistakes made by others if they are made aware of what those mistakes may have been? This study shares many findings on accidental peanut exposures in children in Canada.

                The key points to carry with you

  1. Accidental exposures occur in 12% of the peanut sensitive children annually- exposures are not that common. We would hope that it would be 0%/year, but accidents can happen.
  2. Most of these exposures were soon after the diagnosis was made- a critical time to educate and troubleshoot as the family starts off on this journey.
  3. Education about avoidance is crucial at the time of the diagnosis and should be re-enforced- especially early on.
  4. Almost all children (98%) with a positive test/story for peanut have an epinephrine auto-injector. Should not all children with this have an epinephrine auto-injector?  If the call is made the prescription should be written.
  5. Not all accidental exposures caused more significant reactions, only about 25% were worse.
  6. Not all reactions to peanut are severe, 15% were severe
  7. About 15% of children in this study had a positive test to peanut and no history of a reaction
  8. The most common route of an accidental exposure is oral.
  9. Over 50% of the reactions occurred in the child’s home or the home of a relative/friend. This point I found unbelievable, especially when 40% of the exposures were in the child’s home! This can and must be changed for the sake of the peanut sensitive child.
  10. Epinephrine was not used when it should have been used. When one troubleshoots a bad outcome from a peanut exposure one common theme arises; the use of epinephrine was too late to make a difference. Epinephrine is your best friend for a moderate/severe reaction. This point must be stressed to families and to healthcare providers.

There are a number of risks that can be eliminated.

FEL (4-18-2012)

April 18, 2012 · fleickly · 2 Comments
Tags: , , ,  · Posted in: Allergy in Children, Article Review, Food Allergies, Interesting articles, Peanut Allergy, Pediatric Allergy

2 Responses

  1. Rita - May 3, 2012

    Thanks for posting this! I always imagined the rate of accidental exposure would be much higher and that the majority of exposures would happen places outside of the home. This has slightly eased the knot I get in my stomach when I think of my son starting school.

  2. fleickly - May 6, 2012

    I was surprised as well. One would have thought that the home would have been the safest place. Thanks for posting.
    Warmest regards,