Diagnosis and Management of Bullous Impetigo Progressing to Secondary Cellulitis

Clinical Presentation and Diagnosis

The clinical presentation of bullous impetigo progressing to secondary cellulitis is characterized by a macular rash with itching and burning, followed by blister formation with silvery crusts, and subsequent development of cellulitis, indicating deeper tissue invasion by streptococci or staphylococci 1.
The Infectious Diseases Society of America recommends examining interdigital toe spaces for tinea pedis, fissuring, or maceration, as these are portals of entry for bacteria 3, 1.
Systemic signs such as fever, tachycardia, or confusion suggest deeper infection requiring hospitalization, according to the Clinical Infectious Diseases guidelines 1, 2.

The American College of Physicians recommends hospitalizing patients immediately if they present with systemic inflammatory response syndrome (SIRS), hypotension, hemodynamic instability, altered mental status, severe immunocompromise, or concern for necrotizing infection 1, 2.
For outpatient management of mild to moderate cases, the Infectious Diseases Society of America suggests first-line therapy with clindamycin 300-450 mg orally every 6 hours for 5 days, which covers both streptococci and MRSA 1, 2.
Alternative regimens for outpatient management include trimethoprim-sulfamethoxazole plus cephalexin, or doxycycline plus cephalexin, according to the Clinical Infectious Diseases guidelines 2.
For inpatient management of severe cases, the Society of Healthcare Epidemiology of America recommends vancomycin plus piperacillin-tazobactam, which provides MRSA coverage and broad-spectrum coverage for streptococci and polymicrobial infection 1, 2.

The American College of Physicians recommends elevating both feet above heart level for at least 30 minutes three times daily to promote gravity drainage, and examining and treating interdigital toe spaces for tinea pedis with topical antifungals 3, 1, 4.
The Infectious Diseases Society of America suggests keeping skin well hydrated with emollients to prevent cracking, and considering systemic corticosteroids in non-diabetic adults to reduce inflammation 3, 1, 4.
For wound care, the Clinical Infectious Diseases guidelines recommend gently debriding crusts with saline-soaked gauze, applying topical mupirocin 2% ointment three times daily, and covering with non-adherent dressings to prevent autoinoculation 4.

The American College of Physicians recommends treating underlying venous insufficiency with compression stockings, managing lymphedema with elevation, compression, and diuretics, and considering prophylactic antibiotics if there are three or more episodes per year despite treating predisposing factors 3, 4.
The Infectious Diseases Society of America suggests penicillin V 250 mg orally twice daily, erythromycin 250 mg orally twice daily, or benzathine penicillin 1.2 MU IM monthly as prophylactic antibiotics 2, 4.