Prevention of asthma in childhood

Why are some children with early onset of asthma getting better over the years?--diagnostic failure or salutogenetic factors

Among children earlier having been identified with a hospital or primary care diagnosis of asthma at least once between 0-7 years of age, almost 40 % of their parents reported in the ISAAC-questionnaire as never having had asthma (NA). These are further analysed and compared with the persisting asthma cases (A) in this study. All these children's medical records were scrutinized concerning their asthma diagnose retrospectively.The aim of this study was to analyse possible factors related to the outcome in an Asthma diagnosis reassessment by parental questionnaire at the age of ten of the children earlier having been identified with a hospital or primary health care diagnosis of asthma at least once between 0-7 years of age in a total birth-year cohort in a defined Swedish geographical area.A multiple logistic analysis revealed four significant and independent factors associated to the improvement/non-report of asthma at the age of ten. These factors were; not having any past experiences of allergic symptoms (p<0.0001), only having one or two visits at the hospital for asthma diagnosis in the 0-7 interval (p=0.001), not living in a flat but a villa at the age of ten (p=0.029) and no previous perception of mist or mould damage in the house (p=0.052).In the early postnatal stage, obstructive and bronchospastic symptoms typical of asthma may be unspecific, and those cases not continuing to persisting disease tend to have identifiable salutogenetic factors of constitutional rather than environmental nature, namely, an overall reduced allergic predisposition.

Early-life environment, developmental immunotoxicology, and the risk of pediatric allergic disease including asthma

Incidence of childhood allergic disease including asthma (AD-A) has risen since the mid-20th century with much of the increase linked to changes in environment affecting the immune system. Childhood allergy is an early life disease where predisposing environmental exposures, sensitization, and onset of symptoms all occur before adulthood. Predisposition toward allergic disease (AD) is among the constellation of adverse outcomes following developmental immunotoxicity (DIT; problematic exposure of the developing immune system to xenobiotics and physical environmental factors). Because novel immune maturation events occur in early life, and the pregnancy state itself imposes certain restrictions on immune functional development, the period from mid-gestation until 2 years after birth is one of particular concern relative to DIT and AD-A. Several prenatal-perinatal risk factors have been identified as contributing to a DIT-mediated immune dysfunction and increased risk of AD. These include maternal smoking, environmental tobacco smoke, diesel exhaust and traffic-related particles, heavy metals, antibiotics, environmental estrogens and other endocrine disruptors, and alcohol. Diet and microbial exposure also significantly influence immune maturation and risk of allergy. This review considers (1) the critical developmental windows of vulnerability for the immune system that appear to be targets for risk of AD, (2) a model in which the immune system of the DIT-affected infant exhibits immune dysfunction skewed toward AD, and (3) the lack of allergy-relevant safety testing of drugs and chemicals that could identify DIT hazards and minimize problematic exposure of pregnant women and children.