What is the recommended treatment for acute sinusitis in a 19-month-old?

Treatment of Acute Sinusitis in a 19-Month-Old

For a 19-month-old with acute bacterial sinusitis, high-dose amoxicillin-clavulanate (80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate in 2 divided doses) is the recommended first-line treatment due to the child's age under 2 years. 1

Initial Treatment Decision Algorithm

The first step is determining whether to treat with antibiotics immediately or observe:

• Severe or worsening illness: Always treat with antibiotics immediately 1

  • High fever (≥39°C/102.2°F) for at least 3 consecutive days with purulent nasal discharge 1
  • Worsening symptoms after initial improvement 1

• Persistent illness: Either antibiotic therapy OR additional 3-day observation period is acceptable 1

  • Nasal discharge or cough for ≥10 days without improvement 1
  • Shared decision-making based on symptom severity and caregiver preference 1

Antibiotic Selection for Children Under 2 Years

Because this child is 19 months old (under 2 years), high-dose amoxicillin-clavulanate is strongly preferred over standard-dose amoxicillin. 1, 2 Children under 2 years are considered high-risk for antibiotic-resistant organisms, particularly penicillin-resistant Streptococcus pneumoniae. 1, 3

Dosing Specifications:

• High-dose amoxicillin-clavulanate: 80-90 mg/kg/day of amoxicillin component with 6.4 mg/kg/day clavulanate, divided into 2 doses daily (maximum 2 grams per dose) 1, 2
• This formulation provides adequate coverage against β-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis 1

Alternative if Standard Amoxicillin is Chosen:

• High-dose amoxicillin alone: 80-90 mg/kg/day in 2 divided doses 1, 3
• However, amoxicillin-clavulanate is preferred in this age group 1

Penicillin Allergy Alternatives

If the child has a documented penicillin allergy:

• Second or third-generation cephalosporins are safe alternatives 1, 2

  • Cefdinir, cefuroxime, or cefpodoxime 2, 3
  • Recent evidence shows minimal cross-reactivity risk between penicillins and second/third-generation cephalosporins 1, 2

• Avoid azithromycin: Not recommended due to high resistance rates of S. pneumoniae and H. influenzae 4, 2, 5

Special Circumstances Requiring Parenteral Therapy

Ceftriaxone 50 mg/kg as a single IM or IV dose should be used if: 1, 2

• Child is vomiting or unable to tolerate oral medication 1, 2
• Concerns about adherence to oral antibiotics 2
• Child appears toxic or acutely ill 1

After ceftriaxone administration:

• If clinical improvement occurs within 24 hours, switch to oral antibiotics to complete the course 1, 2
• If still significantly febrile or symptomatic at 24 hours, additional parenteral doses may be needed before oral transition 1, 2

Treatment Duration

Treat for 10-14 days total, or continue antibiotics for 7 days after the child becomes symptom-free (resulting in a minimum 10-day course). 1, 4 This individualized approach prevents prolonged unnecessary antibiotic exposure while ensuring adequate treatment. 1

Reassessment Protocol

Mandatory reassessment at 72 hours after starting treatment: 1

• Worsening symptoms (progression of initial symptoms or new symptoms): Change antibiotic immediately 1
• Failure to improve (no reduction in presenting symptoms): Consider changing antibiotic 1
• Improving symptoms: Continue current antibiotic for full course 1

If treatment fails at 72 hours, switch to an alternative antibiotic with broader coverage, such as high-dose amoxicillin-clavulanate if not already used, or consider ceftriaxone. 1

Critical Warning Signs Requiring Immediate Specialist Referral

Watch for complications, particularly orbital involvement (common in children under 5 with ethmoid sinusitis): 1, 2

• Periorbital or orbital swelling with proptosis 1, 2
• Impaired extraocular muscle function 1, 2
• Severe headache with photophobia 2
• Seizures or focal neurologic findings 2

These require immediate contrast-enhanced CT imaging and otolaryngology consultation. 1 Consider inpatient IV therapy with cefotaxime or ceftriaxone. 1

Common Pitfalls to Avoid

• Do not obtain imaging for uncomplicated acute bacterial sinusitis—diagnosis is clinical 2, 6
• Do not use trimethoprim/sulfamethoxazole or azithromycin due to high resistance rates 4, 2
• Do not underdose in young children—use high-dose formulations for those under 2 years 1, 2
• Do not delay reassessment—failure to improve by 72 hours requires action 1

Adjunctive Therapy

Intranasal corticosteroids may be beneficial as adjunctive therapy to antibiotics, though evidence in young children is limited. 4, 2 Supportive measures include adequate hydration, analgesics for pain/fever, and elevating the head during sleep. 4