Entry age into day care and later development of allergic disorders--results from the city of Leipzig cohort of the LISA study.

The situation in early childhood is supposed to be a risk factor for later development of allergic diseases. The birth cohort from the LISA (Lifestyle-Immune System-Allergy) study gave us the opportunity to investigate the relationship between early childhood situation and the development of allergic diseases. This paper describes our findings regarding to the relationship between entry age into day care and obstructive bronchitis as well as allergic rhinitis and atopic eczema. Study was designed as a longitudinal birth cohort study. Children were examined by a physician at birth, 1/2 year, 1 year, 1 1/2 year, 2 years, 3 years and 4 years. Further information was collected using a structured questionnaire which was answered by the parents. Outcomes under investigation were atopic eczema, allergic rhinitis, wheezing (with and without cold), obstructive bronchitis and asthma (after 2nd year of life). Logistic regression analysis adjusted for infectious diseases of the mother during pregnancy, vaccination of the mother during pregnancy, antibiotics, prenatal smoking of the mother or other persons in the apartment and vaccination state showed an significant promoting effect of entry age into day care against obstructive bronchitis over the first three years of life (OR 1/2 year: 8.55; 95%CI: 2.93...24.97; OR 1st year: 4.96; 95% CI: 1.73...14.24; OR 2nd year: 3.06 95% CI: 1...9.37). A further significant effect was found for crowding against asthma in the fourth year of life (OR 25.7; 95%CI: 1.65...400.17). No significant effects were found between the other periods under investigation (1st year until 4th year of life). On the base of our findings we recommend an entry age into day care of more than six months to prevent effects shown.