Purpose of the Study. To evaluate the relationship between total serum immunoglobulin E (IgE) levels and the risk of allergic sensitization and persistent wheezing in a hospital-based cohort of infants with recurrent wheezing and no signs of allergy.
Study Population. Initially, 58 full-term infants who were seen in a hospital-based asthma clinic in Milan, Italy, were enrolled in the study. At the time of enrollment, the infants were between 9 months and 2 years old. The median age was 1.6 years. Inclusion criteria were a history of wheezing triggered by infections, ≥5 wheezing episodes, no history of atopy, and negative skin tests.
Methods. The children were followed until age 8 years. Skin tests were performed once per year. Testing was performed to egg, milk, wheat, cat, dog, and common aeroallergens. Serum IgE was measured between the ages of 0.5 to 3 years and then again between the ages of 3 and 6 years. An IgE level was performed 4 weeks or more after an acute respiratory illness. IgE levels were reported as IgE z scores.
Results. Thirteen children were lost to follow-up. During the first 3 years, the remaining 45 children had a median of 10 episodes of wheezing (range: 5–34 episodes). The frequency of wheezing decreased during the next 3 years with a median of 6 and a range of 0 to 26 episodes of wheezing. In the last year of the study, only one third or 15 still experienced wheezing. Sensitization to at least 1 allergen was observed in 9 children and was detected between the ages of 5 and 8 years of age. Within this group, 5 had stopped wheezing and 4 were still symptomatic during the last year of the study. The mean IgE z score decreased significantly (P = .0002) from 2.63 during the first 3 years to 2.02 between ages 3–6 years. The average IgE z score at age 0.5 to 3 years was not significantly different between those with positive or negative skin tests. In those between the ages of 3 and 6, the IgE z score was significantly higher (P = .013) in those with positive skin tests, but was not associated with recurrence of wheezing. There was no association between the IgE z scores at entry and the number of wheezing episodes between ages 3 and 8 years or with the presence of wheezing in the last year of the study.
Conclusion. Total serum IgE in infants with recurrent wheezing and no allergy does not help predict those who are at risk for recurrent or persistent wheezing or atopic sensitization.
Reviewer’s Comments. It would be helpful for patient care and for parental concern to know which infant is at risk for persistent asthma. Serum IgE levels have been looked at in different populations, but not in those who have already declared themselves with severe disease. This study involves a small number of children, but they are those infants who have more severe disease and are followed in a specialty clinic. This is a population that does tend to have more asthma morbidity. This paper also has a few other very interesting findings. In their population, wheezing was resolved in 2/3. Skin testing was performed over consecutive years and sensitization to ≥1 allergen was only found in 9 of the 45. In this group of 9, 5 had stopped wheezing, and 4 continued to wheeze. In this population of severely affected infants, there was the tendency for the disorder to resolve and just over 10% of the group had allergy and persistent wheezing.
- Rusconi F, Patria MF, Cislaghi GU, Sideri S, Gagliardi L. Arch Dis Child.2001;85 :23– 25
- Copyright © 2002 by the American Academy of Pediatrics