This is a prospective, randomized, double-blind, placebo controlled one-center study carried out in primary care setting of the health center of City of Turku, Finland. The study patients will be allocated to one of the two parallel treatment groups (amoxicillin-clavulanate or placebo). The hypothesis is that the symptoms and signs of acute otitis media are resolved more effectively with antimicrobial treatment than with placebo. Furthermore, this study aims at finding out prognostic factors that could help to direct antimicrobial treatment for correct subgroups of young patients.

Inclusion Criteria:

• Acute otitis media
• Age 6 - 35 mo

Exclusion Criteria:

• Spontaneous perforation of the tympanic membrane and drainage
• Systemic or nasal corticosteroid therapy within 3 preceding days
• Antihistamine therapy with 3 preceding days
• Oseltamivir therapy within 3 preceding days
• Allergy to amoxicillin/penicillin
• Tympanostomy tube present in tympanic membrane
• Clinical evidence of infection requiring systemic antimicrobial treatment
• Documented Ebstein Barr virus infection within 7 preceding days
• Down syndrome or other condition to affect middle ear infections
• Known immunodeficiency
• Vomiting or another symptom to violate per oral dosage
• Poor parental co-operation due to language or other reasons
• Use of any investigational drugs during the 4 preceding weeks