From atopic dermatitis to asthma: the risk factors and preventive measures

Irreversible airway obstruction in asthma: what we lose, we lose early

Asthma, a syndrome manifested by airway inflammation and obstruction, globally contributes significantly to morbidity and mortality. Although current evidence identifies risk factors that evoke asthma, critical questions concerning susceptibility factors that induce severe persistent disease remain unclear. Early onset of asthma decreases lung function that may be unrecognized until later in adulthood when patients experience dyspnea on exertion and attenuated quality of life. This review highlights current evidence in predicting the onset of asthma and identifying those patients at greatest risk for severe persistent disease.

Effect of prenatal exposure to fine particulate matter and intake of Paracetamol (Acetaminophen) in pregnancy on eczema occurrence in early childhood

The goal of the study was to test the hypothesis that prenatal Paracetamol exposure increases the risk of developing eczema in early childhood and that this association may be stronger in children who are exposed in fetal period to higher concentrations of fine particulate matter (PM2.5). The study sample consisted of 322 women recruited from January 2001 to February 2004 in the Krakow inner city area who gave birth to term babies and completed 5-year follow-up. Paracetamol use in pregnancy was collected by interviews and prenatal personal exposure to PM2.5 over 48 h was measured in recruited women in the second trimester of pregnancy. After delivery, every three months in the first 24 months of the newborn's life and every 6 months later, a detailed standardized face-to-face interview on the infant's health was administered to each mother by trained interviewers. During the interviews at each of the study periods after birth, a history of eczema was recorded. The incident rate ratio (IRR) for frequency of eczema events over the follow-up was estimated from the Poisson regression model and the overall effect of main exposure variables on eczema was assessed by odds ratios (ORs) by the logistic model. The estimated relative risk of eczema occurring whenever in the follow-up was related significantly neither with prenatal Paracetamol nor higher PM2.5 exposure, however, their joint effect was significant (OR interaction term=6.04; 95%CI: 1.04-35.16). Of potential confounders considered in the analysis only damp/moldy home significantly increased the risk of eczema (OR=1.53; 95%CI: 1.14-2.05). In contrast, there was an inverse significant association between the presence of older siblings and eczema (OR=0.55; 95%CI: 0.35-0.84). The joint effect of the main exposure variables significantly increased frequency of eczema events (IRR=1.78, 95%CI: 1.22-2.61). In conclusion, the findings of the study suggest that Paracetamol use by mothers in pregnancy is not an independent risk factor for eczema in children, however, even very small doses of Paracetamol taken in pregnancy may contribute to the occurrence of allergic symptoms in early childhood if there is prenatal co-exposure to higher airborne fine particulate matter.

Effects of prenatal and perinatal exposure to fine air pollutants and maternal fish consumption on the occurrence of infantile eczema

BACKGROUND

As there is a scarcity of evidence on potential hazards and preventive factors for infantile eczema operating in the prenatal period, the main goal of this study was to assess the role of prenatal exposure to fine particulate matter and environmental tobacco smoke (ETS) in the occurrence of infant eczema jointly with the possible modulating effect of maternal fish consumption.

METHODS

The study sample consisted of 469 women enrolled during pregnancy, who gave birth to term babies (>36 weeks of gestation). Among all pregnant women recruited, personal measurements of fine particulate matter (PM₂.₅) were performed over 48 h in the second trimester of pregnancy. After delivery, every 3 months in the first year of the newborn's life, a detailed, standardized, face-to-face interview was administered to each mother, in the process of which a trained interviewer recorded any history of infantile eczema and data on potential environmental hazards. The estimated risk of eczema related to higher prenatal exposure to fine particulate matter (PM₂.₅ > 53.0 μg/m³) and postnatal ETS as well as the protective effect of maternal fish intake were adjusted for potential confounders in a multivariable logistic regression model.

RESULTS

While the separate effects of higher prenatal PM₂.₅ and postnatal ETS exposure were not statistically significant, their joint effect appeared to have a significant influence on the occurrence of infantile eczema [odds ratio 2.39, 95% confidence interval (CI) 1.10-5.18]. With maternal fish intake of more than 205 g/week, the risk of eczema decreased by 43% (odds ratio 0.57, 95% CI 0.35-0.93). The incidence rate ratio (IRR) for eczema symptoms, estimated from the Poisson regression model, was increased with both higher exposure to prenatal PM₂.₅ and postnatal ETS (IRR 1.55, 95% CI 0.99-2.44) and in children of atopic mothers (IRR 1.35, 95% CI 1.04-1.75) but was lower in girls (IRR 0.78, 95% CI 0.61-1.00). The observed preventive effect of fish consumption on the frequency of eczema symptoms was consistent with the results of the logistic analysis (IRR 0.72, 95% CI 0.52-0.99).

CONCLUSIONS

The findings indicate that higher prenatal exposure to fine particulate matter combined with postnatal exposure to ETS may increase the risk of infant eczema, while maternal fish intake during pregnancy may reduce the risk of infantile eczema.

Development of allergies and asthma in infants and young children with atopic dermatitis--a prospective follow-up to 7 years of age

BACKGROUND

The prognosis of atopic dermatitis is usually good, but the risk of developing asthma and allergic rhinitis is very high. The aim of this study was to follow children with atopic eczema up to school age to chart the course of sensitization and development of clinical allergy, as well as to study risk factors of sensitization.

METHODS

Ninety-four children with atopic dermatitis were followed up to 7 years of age. The children were examined twice a year up to 3 years of age, and thereafter once yearly. At each visit, a clinical examination was performed, and a blood sample was taken. After 3 years of age, skin prick tests (SPTs) with inhalation allergens were performed at each visit. Information was obtained about atopy in the family, feeding patterns during infancy, symptoms of atopic disease, infections, and environmental factors.

RESULTS

During the follow-up, the eczema improved in 82 of the 94 children, but 43% developed asthma and 45% allergic rhinitis. The risk of developing asthma was higher in children with a heredity of eczema. Presence of severe eczema at the time of inclusion in the study was associated with an increased tendency to produce food-specific IgE. An early onset of eczema was associated with an increased risk of sensitization to inhalant allergens, and development of urticaria. Early allergic reactions to food were associated with later reactions to food, allergic rhinitis, urticaria, and sensitization to both food and inhalant allergens. Early feeding patterns, time of weaning, and introduction of solid food did not influence the risk of development of allergic symptoms. A large number of periods or days with fever during the follow-up was associated with an increased risk of developing allergic rhinitis and urticaria.

CONCLUSIONS

Our results confirm the good prognosis for the dermatitis and the increased risk of developing asthma and allergic rhinitis. Development of other allergic symptoms or sensitization was associated with the following factors: a family history of eczema, age at onset of eczema and its severity, early adverse reactions to foods, and proneness to infections.