Management of Skin Infections in Patients with Sulfa Allergy

Introduction to Alternative Antibiotics

The American College of Physicians and Infectious Diseases Society of America recommends cephalexin, dicloxacillin, clindamycin, or doxycycline/minocycline as first-line oral antibiotics for patients with sulfa allergies and skin infections, depending on the suspected presence of methicillin-susceptible or methicillin-resistant Staphylococcus aureus (MRSA) 1, 2

Dicloxacillin 500 mg four times daily is the oral agent of choice for methicillin-susceptible strains, according to the Infectious Diseases Society of America 1
Cephalexin 500 mg four times daily is appropriate for penicillin-allergic patients, except those with immediate hypersensitivity reactions, as recommended by the American Academy of Allergy, Asthma, and Immunology 1
Clindamycin 300-450 mg three times daily is effective, though there is potential for cross-resistance with erythromycin-resistant strains, as noted by the Centers for Disease Control and Prevention 1, 2

Dicloxacillin: 25 mg/kg/day in 4 divided doses, as recommended by the American Academy of Pediatrics 1
Cephalexin: 25 mg/kg/day in 4 divided doses, according to the American Academy of Pediatrics 1
Clindamycin: 10-20 mg/kg/day in 3 divided doses orally, as recommended by the Infectious Diseases Society of America 1

Doxycycline 100 mg twice daily is a bacteriostatic option with limited recent clinical experience, as noted by the Centers for Disease Control and Prevention 1, 2
Minocycline 100 mg twice daily has similar efficacy to doxycycline, according to the Infectious Diseases Society of America 1
Clindamycin 300-450 mg three times daily can be used if local resistance rates are low (e.g., <10%), as recommended by the American College of Physicians 2
Linezolid 600 mg twice daily is a bacteriostatic option with no cross-resistance, but is expensive, as noted by the Infectious Diseases Society of America 1, 2

Tetracyclines (doxycycline, minocycline) should not be used in children under 8 years of age, except doxycycline can be used safely in children ages 2 years and older when given for durations less than 2 weeks, as recommended by the American Academy of Pediatrics 1, 2, 4

Vancomycin 30 mg/kg/day in 2 divided doses IV (adults) or 40 mg/kg/day in 4 divided doses IV (pediatrics) is the drug of choice for MRSA, according to the Infectious Diseases Society of America 1, 2
Daptomycin 4 mg/kg every 24 hours IV is a bactericidal option with possible myopathy risk, as noted by the Centers for Disease Control and Prevention 1
Linezolid 600 mg every 12 hours IV is an alternative with no cross-resistance, as recommended by the Infectious Diseases Society of America 1, 2

Mupirocin 2% topical ointment is the best topical agent for impetigo and minor infections, according to the Infectious Diseases Society of America 2, 3

7 days of therapy is typical for most uncomplicated skin infections, depending on clinical response, as recommended by the American College of Physicians 1
5-7 days is sufficient if antibiotics are necessary for minor infections, according to the Infectious Diseases Society of America 5
7-14 days for complicated skin and soft tissue infections in hospitalized patients, as recommended by the Infectious Diseases Society of America 2

Do not use TMP-SMX as a single agent for initial treatment of cellulitis because of possible Group A Streptococcus etiology and intrinsic resistance, as noted by the American Academy of Pediatrics 4
Reevaluate patients in 24-48 hours if sent home on empirical therapy to verify clinical response, as recommended by the Infectious Diseases Society of America 3
Assume MRSA in severe or progressive infections given high prevalence of community-associated MRSA strains, according to the Centers for Disease Control and Prevention 3
Check for penicillin allergy type: Cephalexin can be used in penicillin-allergic patients except those with immediate hypersensitivity reactions, as recommended by the American Academy of Allergy, Asthma, and Immunology 1
Verify clindamycin susceptibility if cultures obtained, as resistance is common in MRSA, as noted by the Infectious Diseases Society of America 2, 3