Treatment of Bullous Impetigo

Causative Organism and Diagnosis

Bullous impetigo is caused exclusively by Staphylococcus aureus strains that produce toxins cleaving the dermal-epidermal junction, forming fragile, thin-roofed vesicopustules 1
These lesions may rupture, creating crusted, erythematous erosions often surrounded by remnants of the blister roof 1
Diagnosis is typically made clinically based on the characteristic appearance, though Gram stain and culture of pus or exudates can help identify the causative organism 2, 3
In typical cases, treatment without culture is reasonable 2

The Infectious Diseases Society of America recommends topical mupirocin or retapamulin applied twice daily for 5 days as first-line therapy for limited bullous impetigo 2, 3
Oral antibiotics are recommended for patients with numerous lesions 2, 3
Oral antibiotics are recommended for outbreaks affecting several people to decrease transmission 2, 3
A 7-day course with an agent active against S. aureus is the recommended oral regimen 2, 3
For methicillin-susceptible S. aureus, dicloxacillin or cephalexin are recommended 2, 3
For suspected or confirmed MRSA, doxycycline, clindamycin, or sulfamethoxazole-trimethoprim are recommended 2, 3

Monitor for clinical response within 24-48 hours when using oral antibiotics 4
If progression occurs despite antibiotics, consider infection with resistant organisms or presence of a deeper, more serious infection than initially recognized 4
For patients with severe infection or progression despite empirical therapy, consider agents effective against MRSA, such as vancomycin, linezolid, or daptomycin 4
Base treatment on appropriate Gram stain, culture, and susceptibility results 4

For limited disease, topical mupirocin or retapamulin twice daily for 5 days is recommended 2, 3
For extensive disease or outbreaks, oral antibiotics for 7 days are recommended 2, 3
For MSSA, dicloxacillin or cephalexin are recommended 2, 3
For suspected/confirmed MRSA, doxycycline, clindamycin, or SMX-TMP are recommended 2, 3

The American Academy of Dermatology notes that bullous impetigo should not be confused with bullous pemphigoid, which is an autoimmune blistering disorder requiring different treatment 5

The Infectious Diseases Society of America recommends considering MRSA coverage if there is no response to first-line treatment or in areas with high MRSA prevalence, although the specific recommendation is not provided in the article, it can be inferred that MRSA coverage is crucial in certain cases 5

The American College of Physicians recommends vancomycin as an effective agent against MRSA for patients with severe or progressive infection 6
Approximately 50% of MRSA strains have inducible or constitutive resistance to clindamycin, with treatment failure rates reaching 21% in some series 6

In areas with high MRSA prevalence, empirical coverage against MRSA should be considered from the start 6

The British Journal of Dermatology warns against confusing bullous impetigo with bullous pemphigoid, an autoimmune blistering disorder requiring different treatment with topical or systemic corticosteroids and immunosuppressive agents, particularly in elderly patients with a chronic course 7, 8, 9