Children who survive traumatic events are at a higher risk of allergy and asthma, recent research suggests.
Researchers in Leipzig, Germany have found that such events directly affect the immune system.
Dr. Gunda Herberth and colleagues at the Helmholtz Center for Environmental Research said that stressful events during childhood are increasingly suspected of playing a role in the later development of asthma, allergic skin disorders, and allergic “sensitizations.” They took blood samples from 234 6-year-old children participating in the ongoing the LISAplus (Life style-Immune System-Allergy) study. The blood was tested to measure levels of a stress-related hormone called VIP and immune markers such as IL-4, which are related to risk of allergic reactions. Life events such as severe disease, death of a family member, and parental unemployment or divorce were assessed by having parents fill out a questionnaire.
Families were followed for six years. Over the course of the study, nearly a third of the families were affected by unemployment. Severe illness was experienced in approximately half of all families. Death among family members or the separation of parents affected one child in ten.
Children with separated or divorced parents showed particularly high VIP levels and immune markers, as did those who had moved. However, severe disease, parental unemployment or death of a family member led to “no remarkable changes,” Herberth said. “As tragic as these events are, they are obviously of less significance for the stress reactions of children than for example a separation or the divorce of parents.” Full details are published in the journal Pediatric Allergy and Immunology.
The link between stress and immune system function is not yet well understood.
The researchers say it is widely believed that major events can have an influence on the development of allergies.
Parental stress also can raise the risk of wheezing among children with no family history of asthma. A team from the University of Southern California who gathered information on 2,888 children and found the effect was particularly evident among boys. The experts say their results, which highlight “the influence of psychosocial factors on asthma, such as stress and social environment,” deserve increased attention.
The researchers from Leipzig also discovered links with eczema. They set out to investigate the various lifestyle factors which are associated with risk of eczema. Some previous studies suggest that stress increases the risk, but few have investigated the association of early stressful life events and eczema in children. The German team found that risk of eczema is raised among children who have lived through divorce.
The researchers asked parents of children in the LISA study group for information on the children’s life events, and whether they had suffered from eczema. Overall, one in five of the children had developed eczema by age four. Analysis showed that divorce or separation of parents was associated with a “significantly increased incidence of eczema for the subsequent two years of life.” Findings appear in the journal Allergy. However, these children may benefit from psychological support. A team from University College, London, analyzed eight studies testing a range of approaches such as aromatherapy, psychotherapy, cognitive-behavioral therapy and stress management programs for children. Their study found that reducing psychological stress helped reduce eczema’s severity and symptoms.
Herberth, G. et al. Relation between stressful life events, neuropeptides and cytokines: an epidemiological study. Pediatric Allergy and Immunology, published online February 25, 2008.
Heinrich, J. et al. Atopic eczema in children: another harmful sequel of divorce. Allergy, Vol. 61, December 2006, pp. 1397-402.
Milam, J. et al. Parental stress and childhood wheeze in a prospective cohort study. The Journal of Asthma, Vol. 45, May 2008, pp. 319-23.
Chida, Y. et al. The effects of psychological intervention on atopic dermatitis. A systematic review and meta-analysis. The International Archives of Allergy and Immunology, published online April 20, 2007.