Management of Acute Bacterial Sinusitis with Vestibular Symptoms in Adolescents

Diagnostic Criteria

The American Academy of Pediatrics defines acute bacterial sinusitis when symptoms persist > 10 days without improvement (the “persistent illness” pattern)【1】.
A thick greenish nasal discharge and headache lasting ≥ 10 days meet the persistent‑illness threshold and support the diagnosis【2】.
Physical examination findings such as swollen turbinates indicate ongoing sinus inflammation【2】.
A history of asthma is a recognized predisposing factor for developing bacterial sinusitis【3】.
Purulent nasal discharge alone does not confirm bacterial infection; it is a normal phase of viral upper‑respiratory infection【2】.

Amoxicillin 80–90 mg/kg/day divided twice daily for 10 days is the recommended first‑line regimen, targeting Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis【1】.
Azithromycin and oral third‑generation cephalosporins should be avoided because of high rates of S. pneumoniae resistance【1】.

Fever should resolve within 24–48 hours after initiating appropriate antibiotics【2】.

Vertigo, tinnitus, and mild gait instability accompanying sinusitis are most often due to viral labyrinthitis or vestibular neuritis that can follow an upper‑respiratory infection【2】.
These vestibular symptoms typically improve spontaneously over 1–2 weeks【2】.

Routine imaging (CT, MRI, or plain films is not indicated in uncomplicated acute bacterial sinusitis because it does not alter management【3】).
Imaging frequently shows incidental sinus abnormalities—up to 68 % of symptomatic children and 42 % of healthy children—underscoring its limited diagnostic value【3】.

Population	Percentage with sinus abnormalities on imaging
Symptomatic children	68 %
Healthy children	42 %

Imaging is reserved for cases where complications are suspected (e.g., orbital involvement, intracranial extension, or treatment failure)【3】.

Reassessment should occur 48–72 hours after starting antibiotics; lack of clinical improvement warrants escalation to amoxicillin‑clavulanate and consideration of imaging【2】.
Red‑flag signs that require immediate evaluation include periorbital swelling, proptosis, visual changes, severe headache, altered mental status, or neck stiffness—suggesting orbital or intracranial complications【2】.
Persistent or worsening vertigo beyond 1 week may merit referral to ENT or neurology【1】.

Do not diagnose bacterial sinusitis based solely on green nasal discharge; this finding is common in viral URI【2】.
Do not delay antibiotic therapy when the persistent‑illness criteria (> 10 days) are met【2】.
Do not overlook a patient’s asthma history, as sinusitis can precipitate asthma exacerbations that may need controller therapy【3】.
Do not dismiss vestibular symptoms without documentation; assess for central red‑flags【2】.
Do not prescribe oral corticosteroids for uncomplicated acute bacterial sinusitis unless there is a severe asthma exacerbation; steroids are not indicated for the sinus infection itself【1】.

Uncomplicated viral URIs typically follow a 5-7 day course with symptoms peaking by days 3-6 and then improving, and a child developing new or worsening fever on day 7 represents a deviation from the expected viral trajectory, according to the American Academy of Pediatrics 4, 5
The American Academy of Pediatrics defines three specific criteria for diagnosing acute bacterial sinusitis, including persistent illness, worsening course, and severe onset, with this child meeting the "worsening course" criterion 6, 5
The three diagnostic criteria for acute bacterial sinusitis are: persistent illness, worsening course, and severe onset, with only one of these patterns needing to be present 6, 5

Acute otitis media typically occurs earlier in the illness course and would be identified on physical examination, making it less characteristic in this case 6
Secondary bacterial pneumonia is effectively excluded by a normal chest X-ray, though this imaging was appropriately obtained given the persistent fever 6, 7
Urinary tract infection should always be considered in young children with fever and nonspecific symptoms, but the context of ongoing URI symptoms on day 7 makes ABS more likely 6

First-line treatment for acute bacterial sinusitis is amoxicillin 80-90 mg/kg/day divided twice daily for 10 days, targeting Streptococcus pneumoniae as the predominant pathogen, according to the American Academy of Pediatrics 6
If the child has severe features or recent antibiotic exposure within the past month, use amoxicillin-clavulanate 90 mg/kg/day instead 6
Expect fever resolution within 24-48 hours, and consider switching to amoxicillin-clavulanate if no improvement occurs after 48 hours on amoxicillin 6