The need for therapeutic strategies against URTI in children is highlighted by results of randomized studies on the use of OTC preparations for treatment of common cold in children below 12 years of age, which revealed no significant differences between verum and placebo . Due to insufficient data on the application of nasal decongestants for common cold in children, their use is not recommended in patients below 12 years of age . Upper respiratory tract infections in early childhood can contribute to significant morbidity resulting from respiratory complications even in immunocompetent individuals. To date, no causal therapy is available in most instances, because URTIs are caused predominantly by viral pathogens for which no effective therapeutic agents have been available.
The results of the present study showed no significant difference between the iota-carrageenan and the placebo group on the predefined primary endpoint, the mean of TSS between study days 2–7. This may be due to the low TSS level below 10 at inclusion, which was necessary to avoid a bias by a higher use of co-medications. Furthermore, the concentration of iota-carrageenan which was the same as used in the previous pilot study in adults , may also have an influence on symptom scores. About 90% of children in both study groups received one or more co-medications. In the verum group, predominantly antiinflammatory agents (58%) or antitussives (62%), and less frequently antibiotics (27%) or ß2-sympathomimetics (26%) were prescribed. It is conceivable that the systemic and the local symptom scores were respectively affected by the antipyretic and the antitussive medication; hence negative effects of the unusually high prevalence of patients with multiple co-medications may have masked the effect of the study medication.
The age of the patients in our study ranged between one and 18 years, with a mean of five years. In young children, it is often very difficult to evaluate symptoms like headache, muscle ache or chilliness. These difficulties in evaluating symptoms in children were recently discussed by Taylor et al. , and require careful consideration in future studies in pediatric patient cohorts.
However, the mean difference in time to complete symptom alleviation between the verum and the placebo group was 1.8 days, while the reported effect of neuraminidase inhibitors on the treatment of influenza in adults showed an overall benefit over placebo treatment of approximately one day .
Another secondary objective of the study was determination of the viral pathogens and intranasal viral loads. Recent data demonstrated that specific viral infections and co-infections as well as viral load contribute to disease severity in children with respiratory infections [23–25]. The viruses detected in our study were similar to earlier reports, and did not reveal constellations associated with a particularly high risk of complications. Significantly more children in the verum group tested virus-negative at visit 2, and fewer children displayed multiple viruses or revealed a new viral infection at this time. These findings may have important implications. Recurrent viral episodes prolonging reactive bronchial inflammation are frequently encountered complications of URTI. In this regard, the topical effect of iota-carrageenan could be instrumental by reducing the incidence of subsequent lower respiratory tract involvement.
The major limitations of this study include the restricted performance of no more than two nasal aspirations, because newly acquired viral infections after day 3–5 could have occurred in the placebo group during the follow up period, potentially changing the proportion of patients with no symptoms. A second limitation may be given by the TSS questionnaire, which may not be the most appropriate for a study population with a mean age of 5 years.
Despite the fact that viral load in nasal secretions were reduced by iota-carrageenan, no significant alleviation of symptoms in children with common cold could be observed in this prospective, randomized, placebo-controlled pediatric study.