Rhinovirus-associated wheezing in infancy: comparison with respiratory syncytial virus bronchiolitis

There is increasing evidence that rhinoviruses (RV) are able to cause lower airway infections and to induce wheezing in young children. There are few data on the clinical characteristics of RV infections in infants.

The aim of the study was to compare clinical characteristics of infantile RV infection associated with wheezing and respiratory syncytial virus (RSV) bronchiolitis.

During a 22-month study period in 1992-1993, 100 children younger than 24 months old were hospitalized with respiratory tract infection-associated wheezing. Viral etiology was originally assessed by antibody and antigen assays. Etiologic studies were later supplemented by polymerase chain reaction for RVs (in 2000) and for RSV (in 2002), studied in frozen respiratory samples. There were 81 children with adequate determinations for both RVs and RSV. Twenty-six children had RV and 24 had RSV infection, and these 50 cases form the material of the present study. Atopic dermatitis, oxygen saturation, respiratory rates and clinical scores based on wheezing and retractions and total serum IgE concentrations and blood eosinophil counts were studied in all cases on admission.

The children with RV infection, compared with RSV patients, were older (median, 13 versus 5 months), presented more often with atopic dermatitis (odds ratio, 16.7; 95% confidence interval, 2.22-100) and blood eosinophilia (odds ratio, 2.22; 95% confidence interval, 1.04-50). The groups did not differ from each other with regard to total serum IgE. Oxygen saturation values were lower in children with RSV infection. There were no significant differences in respiratory rates or scores combining wheezing and retractions.

RV-associated wheezing and RSV bronchiolitis, although having rather similar clinical characteristics, differ significantly with regard to age, presence of atopic dermatitis and eosinophilia during infection.