The purpose of this study is to find out whether the children with respiratory infection and the presence of pathogenic bacteria (S. pneumoniae, H. influenzae or M. catarrhalis) in the nasal middle meatus benefit from antimicrobial treatment.

Acute sinusitis is one of the most common disease in children requiring antimicrobial treatment. The diagnosis and treatment outcomes of acute sinusitis are contradictory, and better diagnostic criteria are needed. In adults with acute maxillary sinusitis, bacterial culture results obtained from the nasal middle meatus are comparable to those obtained from sinus puncture and aspiration. In children, the presence of pathogenic bacteria (S. pneumoniae, H. influenzae or M. catarrhalis) in the nasal middle meatus during respiratory infection predicts longer duration of signs and symptoms of common cold.

In this randomized placebo-controlled study, the effect of the antimicrobial treatment (amoxicillin-clavulanate) is examined in children with pathogenic bacteria (S. pneumoniae, H. influenzae or M. catarrhalis) in the nasal middle meatus during respiratory infection. The duration of the symptoms and speed of recovery is recognized by daily symptom-diary, the results are compared between the treatment groups.

Inclusion Criteria:

• acute respiratory infection with nasal symptoms (nasal obstruction or discharge)
• seeking medical help from health centre for the respiratory symptoms
• pathogenic bacteria (S pneumoniae, H influenzae or M catarrhalis) identified from right or left nasal middle meatus in the endoscopically taken swab culture sampling taken by a study investigator (all microbiological analyses are done by the National Public Health Institute´s microbiological laboratory in Oulu)

Exclusion Criteria:

• otitis, tonsillitis or other disease requiring antimicrobial treatment
• respiratory infection within 4 weeks of screening
• antimicrobial treatment within 4 weeks of screening
• allergy to penicillin or amoxicillin