Allergies to food are on the increase - why is that?

Food allergies are rising but it is still unclear why. This is also reflected in guidelines for the prevention and treatment of food allergies. Risk factors are being discussed again.

Food allergies - an update on causes, prevention, treatment

Food allergies are on the rise. However, it is still unclear why. This is also reflected in the recommendations of the individual guidelines for the prevention and treatment of food allergies. The topic of risk factors is also currently being discussed again.

Number of people affected doubled in recent years

The numbers of people affected by food allergies have increased worldwide in recent years. In Great Britain, about 3.5% of newborns were affected in the years 2005 to 2007; in 2009 to 2011, the number was already more than 7%. In the meantime, chicken egg protein allergy has overtaken cow's milk allergy as the most common representative.

The following mutations are associated with food allergies as possible genetic causes:

However, the influence of genetic factors in the development of food allergies is rather rarely observed - the focus is mainly on environmental influences. The possible protective effect of parents is also increasingly being discussed. This is contradicted by the results of an international study. It was found that in Germany in the 1990s, as in China, a large proportion of the parents of affected children did not suffer from allergies. Accordingly, more children were born to "non-allergic" parents than to "allergic" ones.

Breast milk versus hydrolysed infant formula

In addition to the causes, the topic of prevention is also the focus of many studies. A frequently discussed question in this context is nutrition in the first months of life. The recommendations of the various guidelines are clearly in favour of breastfeeding:

Various protective effects for the infant are attributed to breast milk, including:

An association with allergy-related diseases such as asthma has not yet been proven.

Probiotics as prevention in high-risk children?

If risk factors are present during pregnancy, the administration of probiotics is currently being discussed. The recommendations differ. The classification as a potential high-risk child is made if the parents or siblings have a history of the following diseases:

In 2015, the World Allergy Organization (WAO) guidelines recommend the administration of probiotics during pregnancy and breastfeeding if any of the risk factors mentioned are present. For newborns, this is only recommended if they are not exclusively breastfed.

The 2019 ASCIA guidelines, on the other hand, do not recommend supplementing probiotics during pregnancy and breastfeeding - in fact, they explicitly discourage it in children.

Immunotherapy and biologics: not always recommended

After the diagnosis, many parents are faced with the question of a suitable therapy. Here, too, there is an ongoing disagreement. In this context, the role of immunotherapy was again discussed. The main disadvantage is the high expenditure of time and resources. In addition, the susceptibility to external factors such as physical exertion, infections, dietary habits, etc., is seen as a disadvantage.

The objective of immunotherapy also plays an important role in the decision for or against the treatment. The recommendations are also based on the patient's wishes with the aim of increasing the quality of life of those affected as much as possible.

In addition to immunotherapy, biologics are also being used more frequently. The most common examples are omalizumab and dupilumab. Here, too, the rule is to apply only after a detailed risk-benefit assessment. According to experts, the use of proactive treatment strategies should still only be considered in severely affected children.

Prof. Fiocchi, Alessandro, Editor-in-chief, the WAO Journal, APAAACI Online-Symposium 14, The Prevention and Treatment of Food Allergy, Oktober 2021