Frequent ear infections in infancy and the risk of asthma in Mexican American children.

OBJECTIVES: This study examined the associations of history of ear infections in infancy with doctor-diagnosed asthma in a large sample of Mexican American children. METHODS: In this population-based cross-sectional study, parents of 2023 children completed a questionnaire that collected data on doctor-diagnosed asthma, doctor-diagnosed ear infections, as well as antibiotics use in infancy, and other potential confounding variables. RESULTS: Children with a history of ear infections in infancy were more likely to have asthma compared with those who had no history of ear infections in infancy; the adjusted odds ratios (ORs) were 2.52 (95% confidence interval [CI]: 1.35-4.69) and 1.27 (95% CI: 0.79-2.04) in children who had >or=3 and 1-2 (versus none) ear infections in infancy, respectively, p for trend = .0074. These associations were independent of antibiotics use, acetaminophen consumption, and history of various infections (other than ear infections) in the first year of life. In stratified analyses, the increased risk of asthma in children with recurrent ear infections in infancy persisted among children whose parents reported no lifetime history of rhinitis but not in children who had a history of rhinitis. CONCLUSIONS: This study demonstrated significant associations of asthma with history of ear infections in infancy, with a significant dose-response effect of repeated ear infections on the odds of asthma. These findings add to the growing body of literature linking early childhood infections with the risk of asthma and highlight the need for more research to identify the mechanisms through which ear infections may be associated with asthma.

Associations of doctor-diagnosed asthma with immigration status, age at immigration, and length of residence in the United States in a sample of Mexican American School Children in Chicago.

OBJECTIVES: Among Mexican Americans in the United States, children who were born in the US had higher rates of asthma than their Mexico-born peers. The purpose of this study was to examine the associations of doctor-diagnosed asthma with immigration-related variables and to investigate whether these associations could be explained by factors that may change with migration. METHODS: We surveyed parents of 2,023 school children of Mexican descent and examined the associations of asthma with nativity, age at immigration, and length of residence in the US after adjusting for potential confounding variables. RESULTS: In multivariate analyses, US-born children had a 2.42-fold (95% confidence interval [CI]: 1.52-3.83) increased odds of asthma compared with their Mexico-born peers. Mexico-born participants who moved to the US before 2 years of age were almost twice as likely to experience asthma compared with Mexico-born children who moved to the US >or=2 years of age. In addition, Mexico-born participants who lived in the US for 10 years or more were 2.37 times more likely to have asthma than Mexico-born students who lived in the US for less than 10 years. These associations were not explained by a wide variety of factors such as place of residence in infancy; exposure to animals/pets; history of infections, Tylenol use, and antibiotic use in infancy; breastfeeding; exposure to environmental tobacco smoke; daycare attendance and number of siblings; and language use. CONCLUSIONS: Our findings point to the effects of nativity, age at immigration, and duration of residence in the US on the risk of asthma in Mexican American children, suggesting that potentially modifiable factors that change with migration may be linked with the disease. The findings of this study should stimulate further research to explain factors that may be responsible for the observed differentials in the risk of asthma among Mexican Americans.

Duration of illness is an important variable for untreated children with juvenile dermatomyositis.

OBJECTIVE: To evaluate the impact of duration of untreated symptoms in children with juvenile dermatomyositis (JDM) on clinical and laboratory status at diagnosis. STUDY DESIGN: We examined physical and laboratory data from the first physician visit for 166 untreated children with JDM. Disease activity scores (DASs) assessed skin and muscle involvement. Height and weight were compared with the National Health and Nutrition Examination Survey III dataset. Duration of untreated illness was designated as the time from first sign of rash or weakness to diagnostic visit. RESULTS: Boys and girls with untreated JDM were shorter and lighter than national norms (P > .0005 for both), and nonwhite children were weaker than white children (P > .0005). Older children had more dysphagia (P = .017) and arthritis (P > .001). Duration of untreated JDM was negatively associated with DAS weakness (P > .0005), unrelated to DAS skin, and positively associated with pathological calcifications (P = .006). With untreated disease > or = 4.7 months, serum levels of 4 muscle enzymes (aldolase, lactic dehydrogenase, creatine kinase, serum glutamic-oxaloacetic transaminase/aspartate aminotransferase) tended toward normal (P > .01 for each). CONCLUSIONS: Duration of untreated symptoms is an important variable and should be included in decisions concerning both diagnostic criteria and intensity of therapy for children with JDM.