- Ailment does not improve within 48 hours
- Persistent fever, particularly if it already begins in the morning .>38.5 degrees Celsius
- Strong ear pain, sometimes accompanied by ottorhea (liquid excreted from ear)
- Breathing problems (whistling sound during breathing or barking-like sound)
- Important: strong headache, vomiting, light sensitivity, stiff neck – immediate medical control to check for possible meningitis
