Preventing Allergic Conditions and Current Recommendations for Children With an Increased Risk of Allergy

Allergic conditions are amongst some of the most frequently chronic ailments amongst children and adolescents. According to the results of the children's and adolescents' health survey conducted by the Robert Koch Institute, 4.7% of children and adolescents aged between 0 and 17 suffer from bronchial asthma, 10.7% from allergic rhinoconjunctivitis and 13.2% from atopic eczema.

Children are not born with these conditions; they acquire them during the course of their lifetime and "allergy careers" can begin early on in childhood, even as early as infancy. Atopic eczema is usually the first symptom of an allergic reaction (fig. 1) and this can be triggered by an allergy to food early on in childhood (for 30-40% of children with atopic eczema). 

Eczema often recedes in early childhood and children develop tolerances to food allergies. In return, an inhalation allergy often manifests later as allergic rhinitis or asthma (fig. 2). There are various risks for this type of condition to manifest, genetics being the primary risk factor. Children, whose parents both have the same allergic condition (e.g. hay fever), have up to an 80% risk of developing hay fever themselves. The type of nutrition is seen as another specific risk factor, if a baby is not able to breastfeed either sufficiently or at all. Formula containing animal or plant protein (e.g. cow's milk, goats milk, soy milk) increases the risk. Environmental pollution is seen as another risk factor (e.g. passive smoking, noxious vehicle emissions, etc.).

Particular significance is also attributed to the composition of gut flora when it comes to the development of allergic reactions and the method of childbirth (vaginal or Caesarean) appears to play a key role here. The composition of the child's gut flora is shaped during the birth, and children delivered by Caesarean section, with the associated increased exposure to hospital pathogens, have a higher risk of developing allergic reactions than children who are brought into the world via a vaginal delivery and whose gut flora are shaped by the mother's pathogens.

Early inhalation exposure to bacteria also appears to have an impact on the subsequent development of allergic reactions and asthma. So, it makes a difference as to whether the child grows up on a farm with the associated specific bacterial exposure, or whether they grow up in a less rural setting. A current meta analysis confirms a significant risk reduction of about 30% for asthma symptoms, through growing up on a farm.¹

The following factors are currently considered to be specific risk factors in early childhood for the development of allergic reactions:

• Genetics
• Nutrition
• Environmental pollution from noxious substances
• Method of childbirth
• Inhalation exposure to bacteria

The current guidelines on atopy prevention, published by the AWMF (Association of the Scientific Medical Societies in Germany), give the following recommendations for children with a heightened risk of developing allergies (father, mother or siblings have allergies):

• Breastfeeding : Breastfeeding has many benefits for mother and child. Data currently available support the recommendation that a child should be fed purely on breast milk for the first 6 months of their life.
• A mother's diet during pregnancy and/or whilst breastfeeding: A balanced diet that includes a wide range of nutrients is recommended during pregnancy and whilst breastfeeding. There should be no dietary restrictions (avoidance of potent food allergens) during pregnancy or whilst breastfeeding for reasons of primary prevention. There is evidence to suggest that the inclusion of fish in a mother's diet during pregnancy and/or whilst breastfeeding has a protective effect when it comes to the child's development of atopic conditions. Fish should be part of a mother's diet during pregnancy and whilst breastfeeding.
• Breast-milk substitutes for children at risk: If a child is unable to breastfeed, either sufficiently or at all, hydrolyzed formula* should be given to children at risk, as there are studies2 that provide evidence that this is effective. Data currently available support this recommendation for the first 4 months of a child's life. Soy-based formula is not recommended for the purpose of allergy prevention.
• Introducing other foods and nutrition for children in their first year of life: The current recommendation in Germany is to introduce other foods starting at 6 months of age. The introduction of other foods should not be delayed for reasons of allergy prevention. There is no evidence that restricting a child's diet by avoiding potent food allergens in the first year of life has any preventative effect. A child's diet should therefore not be restricted. There is evidence to suggest that a child's consumption of fish in their first year of life has a protective effect on the development of atopic conditions. Fish should be introduced alongside other foods.
• Keeping pets: People with no increased risk of allergy should not hold back from keeping pets. For children at risk, the following applies: Families with an increased allergy risk should not have a cat. Pet dogs are not associated with an increased allergy risk.
• Dust mites: For the purpose of primary prevention, it is not possible to recommend specific measures, e.g. mattress cover (encasing) to reduce exposure to dust mite allergens.
• Vaccinations: There is no evidence to suggest that vaccinations increase the risk of allergies. However, there is evidence to suggest that vaccinations may reduce the risk of allergies. The recommendation is that all children, even children at risk, should be vaccinated in accordance with recommendations (STIKO - Standing Vaccination Committee at the Robert Koch Institute in Germany).
• The impact of probiotics: It has so far only been possible to demonstrate a preventative effect of probiotics for atopic eczema. Owing to the heterogeneity of bacterial strains and the study design, no recommendation can be given regarding specific compounds, forms of application, duration and time of administration.
• The impact of prebiotics: It has so far only been possible to demonstrate a preventative effect of prebiotics for atopic eczema. Due to the low heterogeneity of studies, no recommendation can be given. 

These atopic prevention recommendations apply to children with an increased atopic risk, as the underlying studies were carried out on children with an increased risk of allergies. Part of the discussion is whether these recommendations should also apply to children who have no increased allergy risk.

Until a few years ago, latex allergy was a particular chapter in the story of allergic conditions. Those particularly affected by this latex allergy were primarily children who occasionally had to undergo surgery during infancy or early childhood (e.g. children with spina bifida). Early intraoperative contact with latex materials here resulted in sensitivity to latex. Since surgery has become "latex free", such cases hardly ever occur in current practice.

In the light of this, there has also been discussion as to whether soothers containing latex could give rise to a latex allergy. According to the extant literature on this topic and several decades of clinical experience, there are no indications that soothers containing latex could give rise to a latex allergy.