Food Allergies
10 min read
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Early introduction of allergenic foods
Based on the LEAP study (Learning Early About Peanut), the early introduction of the peanut even in high-risk patients is now widely accepted. But most food allergies are caused by other triggers. This overview discusses the different approaches and studies.
Skin barrier: The role of an impaired skin barrier for food sensitisation and allergies has led to a number of dermatologically oriented studies. Despite the positive outlook of the BEEP study (Barrier Enhancement for Eczema Prevention) and a Japanese study, the large BEEP study and the PreVALL study (EuroPreVALL outpatient clinic study on food allergy) have not shown a significant effect of dermatological prevention on the risk of food allergies.
Environmental influences: The influence of environmental allergens on food allergies is supported by several peanut-related studies. However, it is far more difficult for a family to avoid allergens such as cow’s milk or egg than it is to avoid peanuts.
Other allergies: Of the studies on the early introduction of allergenic foods other than peanuts, 5 treat only the egg, 1 only milk, and EAT (Enquiring About Tolerance) (peanut, egg, milk, sesame, fish and wheat) and Prevent ADALL (Preventing Atopic Dermatitis and Allergies) (peanut, milk, wheat, egg) treat several.
Egg: In their meta-analysis of the early introduction studies, Boyle et al (Ierodiakonou D et al., 2016) found in 5 studies (N = 1,915) that the early introduction of eggs at the age of 4 to 6 months was associated with a reduced egg allergy. Since the prevalence of a peanut allergy in the general population is significantly lower than that of an egg allergy, a programme that recommends early introduction of eggs provides much greater public health benefits.
Maternal diet: A systematic review of 42 studies found no consistent links between the
nutrition of the mother and atopic diseases in their children. The now ongoing PrEggNut-RCT investigates whether a regularly high egg and peanut butter diet during pregnancy can prevent the development of a food allergy at the age of 12 months.
Domestic pets: Two studies have now observed a reduction in food allergies in the first year of life when a dog is kept in the household. In the HealthNuts study, children with a domestic dog were less likely to have egg allergies when they turn one year old.
Many countries and organisations have adopted a recommendation for the early introduction of a wide range of allergenic foods in early childhood, but other institutions still lack sufficient evidence of early introduction.
However, the question remains whether early consumption is food-dependent and whether the required starting age for this varies. Furthermore, it is not known what the consequences are if consumption is started but then only continues sporadically or stops completely. The recommended dose in each case also remains uncertain.
In clinical practice, the change in the assessment of the early introduction of allergens is
now tangible. Families are also increasingly following a strategy of early exposure rather
than avoidance. According to the authors, it will be interesting to see whether this leads to a general cultural change with regard to allergenic foods, which in itself could be a relief.
Perkin MR et al., J Allergy Clin Immunol Pract. 2020
Allergens Intro-Obstacles
In the EAT (”Enquiring About Tolerance“) study on the early introduction of six allergens, the rejection rate was surprisingly high, e.g. 42 % in the youngest group. The participants were therefore asked to give the reasons for this in an open online text questionnaire. Three groups of topics proved to be particularly challenging.
The answers for the analysis represent the early (4, 5 and 6 months), middle (8 and 12 months) and late (24 and 36 months) periods. The responses were coded and then grouped to represent key botanicals.
The three major challenges or obstacles during the early introduction of allergens proved to be:
Some children refused to eat the allergenic food
Parents feared an allergenic effect
Practical difficulties or inconvenience during preparation
Is there a Connection between fruit and pollen allergy?
Fruits are considered to be common allergens. However, there is relatively little data on allergens that cause fruit and vegetable allergies and pollen food allergy syndrome (PFAS) in children. A Japanese multicentre observational study investigated the possible association between fruit/vegetable allergies and PFAS.
Among the participants were children aged <15 years who developed allergic symptoms after eating fruit and vegetables and were subsequently treated in the paediatric department of six hospitals in Osaka Prefecture between August 2016 and July 2017.
A total of 97 children (mean age 9 years; 56 males) were included in the study. Apple was the most common allergen, followed by peach, kiwi, cantaloupe and watermelon.
74 participants (76%) had allergic symptoms due to PFAS; in addition, pathogenesis-related protein-10* (PR-10) was the most common allergen group. In the group without PR-10 or profilin sensitization, kiwi and banana were the most common allergens. The age of onset was lower than in the PFAS group. The specific antibody titre was significantly associated with birch for Bet v1 and latex for Bet v2 (r = 0.99 and r = 0.89).
The recommendation is to initially consider PFAS for patients with fruit and vegetable allergies, especially for children over 4 years of age.
Takemura Y et al., Asia Pac Allergy. 2020
* PR-10 proteins indicate IgE antibody cross-reactivity between homologous allergens in pollen and various vegetables, nuts and fruits.
Based on the LEAP study (Learning Early About Peanut), the early introduction of the peanut even in high-risk patients is now widely accepted. But most food allergies are caused by other triggers. This overview discusses the different approaches and studies.
Skin barrier: The role of an impaired skin barrier for food sensitisation and allergies has led to a number of dermatologically oriented studies. Despite the positive outlook of the BEEP study (Barrier Enhancement for Eczema Prevention) and a Japanese study, the large BEEP study and the PreVALL study (EuroPreVALL outpatient clinic study on food allergy) have not shown a significant effect of dermatological prevention on the risk of food allergies.
Environmental influences: The influence of environmental allergens on food allergies is supported by several peanut-related studies. However, it is far more difficult for a family to avoid allergens such as cow’s milk or egg than it is to avoid peanuts.
Other allergies: Of the studies on the early introduction of allergenic foods other than peanuts, 5 treat only the egg, 1 only milk, and EAT (Enquiring About Tolerance) (peanut, egg, milk, sesame, fish and wheat) and Prevent ADALL (Preventing Atopic Dermatitis and Allergies) (peanut, milk, wheat, egg) treat several.
Egg: In their meta-analysis of the early introduction studies, Boyle et al (Ierodiakonou D et al., 2016) found in 5 studies (N = 1,915) that the early introduction of eggs at the age of 4 to 6 months was associated with a reduced egg allergy. Since the prevalence of a peanut allergy in the general population is significantly lower than that of an egg allergy, a programme that recommends early introduction of eggs provides much greater public health benefits.
Maternal diet: A systematic review of 42 studies found no consistent links between the
nutrition of the mother and atopic diseases in their children. The now ongoing PrEggNut-RCT investigates whether a regularly high egg and peanut butter diet during pregnancy can prevent the development of a food allergy at the age of 12 months.
Domestic pets: Two studies have now observed a reduction in food allergies in the first year of life when a dog is kept in the household. In the HealthNuts study, children with a domestic dog were less likely to have egg allergies when they turn one year old.
Many countries and organisations have adopted a recommendation for the early introduction of a wide range of allergenic foods in early childhood, but other institutions still lack sufficient evidence of early introduction.
However, the question remains whether early consumption is food-dependent and whether the required starting age for this varies. Furthermore, it is not known what the consequences are if consumption is started but then only continues sporadically or stops completely. The recommended dose in each case also remains uncertain.
In clinical practice, the change in the assessment of the early introduction of allergens is
now tangible. Families are also increasingly following a strategy of early exposure rather
than avoidance. According to the authors, it will be interesting to see whether this leads to a general cultural change with regard to allergenic foods, which in itself could be a relief.
Perkin MR et al., J Allergy Clin Immunol Pract. 2020
Allergens Intro-Obstacles
In the EAT (”Enquiring About Tolerance“) study on the early introduction of six allergens, the rejection rate was surprisingly high, e.g. 42 % in the youngest group. The participants were therefore asked to give the reasons for this in an open online text questionnaire. Three groups of topics proved to be particularly challenging.
The answers for the analysis represent the early (4, 5 and 6 months), middle (8 and 12 months) and late (24 and 36 months) periods. The responses were coded and then grouped to represent key botanicals.
The three major challenges or obstacles during the early introduction of allergens proved to be:
Some children refused to eat the allergenic food
Parents feared an allergenic effect
Practical difficulties or inconvenience during preparation
Is there a Connection between fruit and pollen allergy?
Fruits are considered to be common allergens. However, there is relatively little data on allergens that cause fruit and vegetable allergies and pollen food allergy syndrome (PFAS) in children. A Japanese multicentre observational study investigated the possible association between fruit/vegetable allergies and PFAS.
Among the participants were children aged <15 years who developed allergic symptoms after eating fruit and vegetables and were subsequently treated in the paediatric department of six hospitals in Osaka Prefecture between August 2016 and July 2017.
A total of 97 children (mean age 9 years; 56 males) were included in the study. Apple was the most common allergen, followed by peach, kiwi, cantaloupe and watermelon.
74 participants (76%) had allergic symptoms due to PFAS; in addition, pathogenesis-related protein-10* (PR-10) was the most common allergen group. In the group without PR-10 or profilin sensitization, kiwi and banana were the most common allergens. The age of onset was lower than in the PFAS group. The specific antibody titre was significantly associated with birch for Bet v1 and latex for Bet v2 (r = 0.99 and r = 0.89).
The recommendation is to initially consider PFAS for patients with fruit and vegetable allergies, especially for children over 4 years of age.
Takemura Y et al., Asia Pac Allergy. 2020
* PR-10 proteins indicate IgE antibody cross-reactivity between homologous allergens in pollen and various vegetables, nuts and fruits.
