What is a suitable antibiotic for a 9-year-old with sinusitis who is allergic to amoxicillin (amoxicillin)?

Antibiotic Choice for Sinusitis in a 9-Year-Old with Amoxicillin Allergy

For a 9-year-old child with acute bacterial sinusitis and amoxicillin allergy, cefdinir is the preferred first-line antibiotic, with cefpodoxime or cefuroxime as acceptable alternatives. 1, 2

First-Line Treatment for Penicillin-Allergic Children

Cefdinir is the preferred cephalosporin because it offers once or twice daily dosing, higher patient acceptance, and excellent coverage against the common sinus pathogens (Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis). 2

Alternative second- and third-generation cephalosporins that provide appropriate coverage include:

• Cefpodoxime proxetil at 8 mg/kg/day in two divided doses 3, 4
• Cefuroxime axetil 1, 4

These cephalosporins are safe for children with both Type 1 and non-Type 1 hypersensitivity to amoxicillin, as the risk of cross-reactivity with second- and third-generation cephalosporins is negligible. 1, 2

Important Caveat: Verify Allergy Type

Before prescribing any cephalosporin, verify the type of penicillin allergy. 2 If the child has a documented true Type I hypersensitivity reaction (anaphylaxis, angioedema, urticaria), cephalosporins may still be used but require more caution. Recent evidence shows the cross-reactivity risk with second- and third-generation cephalosporins is almost nil. 5

Antibiotics to AVOID

Do NOT use azithromycin or clarithromycin as first-line therapy in this child. 1, 2 Surveillance studies demonstrate significant resistance of S. pneumoniae and H. influenzae to macrolides, with bacterial failure rates of 20-25%. 1, 2 The American Academy of Pediatrics explicitly states that trimethoprim/sulfamethoxazole and azithromycin should not be used to treat acute bacterial sinusitis in persons with penicillin hypersensitivity due to resistance patterns. 1

Treatment Duration and Monitoring

• Standard treatment duration is 10-14 days 1, 6
• Reassess at 72 hours (3 days) if no clinical improvement occurs 1, 4
• If the child fails to respond after 3 days, consider switching to an alternative antibiotic or reevaluating the diagnosis 1, 2

Alternative for True Type I Allergy (If Cephalosporins Cannot Be Used)

If cephalosporins are absolutely contraindicated due to a severe documented Type I hypersensitivity:

• Trimethoprim-sulfamethoxazole, clarithromycin, or azithromycin may be considered, but these have limited effectiveness with bacterial failure rates of 20-25% 2
• Close monitoring is essential with these alternatives due to high resistance rates 2

Parenteral Option for Severe Cases

Intramuscular or intravenous ceftriaxone (50 mg/kg once) can be given if the child is vomiting, cannot take oral medications, or is unlikely to adhere to initial oral therapy. 1 After clinical improvement, switch to oral cephalosporin therapy. 1

Critical Pitfalls to Avoid

• Never use first-generation cephalosporins (cephalexin, cefadroxil) as they have poor coverage for H. influenzae 5
• Avoid macrolides as first-line therapy due to 20-25% resistance rates among respiratory pathogens 1, 2
• Do not use fluoroquinolones in children except in rare circumstances, as they are not indicated for routine pediatric sinusitis 1
• Ensure adequate treatment duration (minimum 10 days) to prevent relapse 1, 6