Genetics, stress linked to childhood allergies, researchers say

By Ernest Gill Sep 1, 2008, 3:08 GMT

Hamburg, Germany - Genetics and emotional stress are two factors which contribute to common allergies such as hay fever among children, according to two separate studies by German researchers.

In one study of 3,000 school pupils in Munich, geneticists discovered evidence that a genetic deficiency in the protein filaggrin in skin cells contributes to common eczema-like skin allergies.

Variants of the filaggrin gene were also associated with dandruff and contact dermatitis, for example rashes caused by nickel jewellery, according to the study conducted by the Munich Helmholtz Centre and the Technical University of Munich.

With certain variants of the gene, a patient was three times as likely to suffer from atopic dermatitis and was also more liable to have hay fever, the study found.

In a separate Helmholtz study, scientists discovered that emotional stress, such as moving to a new town and changing schools or going through parental divorce, is also a risk factor in childhood allergies.

The researchers examined blood samples taken from 234 six-year-old children and discovered increased blood concentrations of the stress-related peptide VIP (vasoactive intestinal polypeptide) in connection with moving house or the separation of parents. The neuropeptide VIP could take on a mediator role between stress events in life and the regulation of immune responses, researchers write in the scientific journal Pediatric Allergy and Immunology.

The findings resulted from a long-term study correlating life-style, immune system development and allergies, led by the Helmholtz Center for Environmental Research in Leipzig (UFZ), the Helmholtz Zentrum Munich and the Institut fuer Umweltmedizinische Forschung (IUF) in Duesseldorf.

It has been known for some time that emotional stress can have an influence on the development of allergies. But the causative mechanisms long remained unexplained. Now, for the first time, stress events were investigated during early childhood within a large epidemiological study using immune and stress markers.

The researchers said they had found definitive proof of a link between stress during childhood and the later development of asthma, allergic skin disorders, or allergic sensitisations. Dramatic life events like the death of a family member, serious illnesses of a family member or the separation of parents, but also harmless events like for example moving house are suspected of increasing the risk of allergies for the children affected.

'The immune system obviously plays a mediator role between stress on the one hand and allergies on the other,' the researchers wrote. 'Since these mechanisms had hardly been understood before, researchers attempted to identify stress-related factors showing an influence on the immune system, in the context of an epidemiological study.'