Treatment of Impetigo

Topical mupirocin 2% ointment applied three times daily for 5-7 days is the first-line treatment for limited impetigo lesions. 1, 2

First-Line Treatment: Topical Antibiotics

Mupirocin 2% ointment should be applied to affected areas three times daily for 5-7 days for limited lesions, as recommended by the American Academy of Pediatrics and the Infectious Diseases Society of America 1
Retapamulin 1% ointment is an effective alternative, applied twice daily for 5 days 1, 3
Clinical efficacy rates for mupirocin in treating impetigo have been demonstrated to be 71-93%, with pathogen eradication rates of 94-100% 2
Mupirocin is specifically indicated for the topical treatment of impetigo caused by Staphylococcus aureus and Streptococcus pyogenes 2

Oral antibiotics are recommended when:
- Impetigo is extensive
- Topical therapy is impractical
- Topical treatment has failed
- Systemic symptoms are present 1, 3
First-line oral antibiotic options include:
- Dicloxacillin (250 mg four times daily for adults)
- Cephalexin (250-500 mg four times daily for adults) 1, 3
For suspected Methicillin-Resistant S. aureus (MRSA):
- Trimethoprim-sulfamethoxazole
- Clindamycin (300-450 mg three times daily for adults)
- Doxycycline (not for children under 8 years) 1, 3

Penicillin alone is not effective for impetigo as it lacks adequate coverage against S. aureus 3, 4
Oral antibiotic dosing should be adjusted by weight for children 3
Tetracyclines (doxycycline, minocycline) should not be used in children under 8 years of age 3
Consider empiric therapy for CA-MRSA in patients at risk for CA-MRSA infection, failure to respond to first-line therapy, or in areas with high local prevalence of CA-MRSA 1

Impetigo is typically diagnosed clinically based on the characteristic honey-colored crusts in nonbullous impetigo (70% of cases) or large, flaccid bullae in bullous impetigo (30% of cases) 4, 5
Cultures of the vesicle fluid, pus, or erosions should be obtained if there is treatment failure, MRSA is suspected, or in cases of recurrent infections 3

Complete the full course of prescribed antibiotics even if symptoms improve quickly, to prevent complications such as post-streptococcal glomerulonephritis 1
Re-evaluate if no improvement after 48-72 hours of therapy 3
Lesions should be kept covered with clean, dry bandages and good personal hygiene maintained to prevent spread 3

Topical disinfectants are inferior to antibiotics and should not be used 4, 6
Rising rates of bacterial resistance should inform treatment decisions, with methicillin-resistant S. aureus, macrolide-resistant streptococcus, and mupirocin-resistant streptococcus all documented 4, 5
If impetigo is not responding to appropriate therapy, consider alternative diagnoses 3
While impetigo usually heals spontaneously within two weeks, treatment helps relieve discomfort, improve appearance, and prevent spread of organisms that may cause other illnesses 6