Acute otitis externa is a common disease in the pediatric population, characterized by diffuse inflammation of the external auditory canal. Typical symptoms of acute otitis externa include otology, itching, congestion, and a feeling of fullness in the sore ear. In the case of active inflammation, the process can go to the tympanic membrane, and acute otitis media will join the external one. Primary therapy for diffuse uncomplicated acute otitis externa should include a local antimicrobial drug, without systemic antibiotic therapy. Topical therapy with antibacterial drugs in combination with anesthetics is the most rational. A clinical case of a 12-year-old patient with acute diffuse otitis externa and otitis media with effusion; acute nasopharyngitis; and adenoiditis, which was established based on anamnesis and clinical data is presented. Complex therapy was prescribed, which included local antibiotic therapy with a complex topical drug for the treatment of imperforated otitis externa and imperforated otitis media. At reexamination 5 days later, the patient demonstrated positive dynamics, pain in the left ear was eliminated. In cases of uncomplicated diffuse otitis externa, as well as in cases of its combination with otitis media with effusion, topical antibiotic therapy is a major priority. It should be borne in mind that the topical medication is more effective with the cleansing of the external auditory canal from inflammatory secretion. If it is used correctly, it would provide positive dynamics without systemic antibiotic prescription. It preserves the microbiome and mobilizes the body’s defenses. The application of complex topical antibiotic drugs can be widely recommended in pediatric practice.