Impetigo Organism-Specific Therapy 

Organism-specific therapeutic regimens for impetigo are provided below, including those for group A beta-hemolytic Streptococcus, methicillin-susceptible Staphylococcus aureus (MSSA), and methicillin-resistant S aureus (MRSA).

Impetigo is a contagious, superficial bacterial infection commonly seen in children. Treatment typically involves local wound care along with topical or systemic antibiotic therapy with activity against beta-hemolytic streptococci and S aureus.

Topical therapy is preferred for localized, uncomplicated nonbullous or bullous impetigo. ^[1] Systemic antibiotics are used with widespread infections, complicated infections, outbreaks of poststreptococcal glomerulonephritis, multiple incidents that have occurred within the home, daycare, or athletic-team settings. The duration of therapy should be based on clinical improvement; however, a 7-day regimen is recommended. ^[2]

The Infectious Diseases Society of America (IDSA) published 2014 guidelines for the treatment of impetigo (see Practice Guidelines for the Diagnosis and Management of Skin and Soft Tissue Infections: 2014 Update by the Infectious Diseases Society of America). ^[2]

Group A beta-hemolytic streptococcal impetigo

Localized, uncomplicated group A beta-hemolytic streptococcal impetigo is treated as follows:

• Mupirocin 2% cream/ointment applied topically BID for 5 days or
• Retapamulin 1% ointment applied topically BID for 5 days

Widespread, complicated group A beta-hemolytic streptococcal impetigo is treated as follows:

• Penicillin V 250-500 mg PO QID for 7 days or
• Amoxicillin 25-40 mg/kg/day divided BID for 7 days or
• Cephalexin 250 mg PO QID for 7 days in adults or 25 mg/kg/day in 4 divided doses for 7 days in children

MSSA impetigo

Localized, uncomplicated MSSA impetigo is treated as follows:

• Mupirocin 2% cream/ointment applied topically BID for 5 days or
• Retapamulin 1% ointment applied topically BID for 5 days

Widespread, complicated MSSA impetigo is treated as follows:

• Cephalexin 250 mg PO QID for 7 days in adults or 25 mg/kg/day in 4 divided doses for 7 days in children or
• Amoxicillin-clavulanate 875 mg/125 mg PO BID for 7 days in adults or 25 mg amoxicillin/kg/day PO divided BID for 7 days in children or
• Dicloxacillin 250 mg PO QID for 7 days in adults/children >40 kg or 25 mg/kg/day PO divided QID for 7 days in patients <40 kg

MRSA impetigo  ^{[3, 4]}

Localized, uncomplicated MRSA impetigo is treated as follows:

• Mupirocin 2% cream/ointment applied topically BID for 5 days or
• Retapamulin 1% ointment applied topically BID for 5 days

Widespread, complicated MRSA impetigo is treated as follows:

• Trimethoprim-sulfamethoxazole TMP 160 mg PO BID for 7 days in adults or 8-12 mg TMP/kg/day PO divided BID for 7 days in children older than 2 months or
• Clindamycin 300 mg PO QID for 7 days in adults or 10-20 mg/kg/dose PO TID for 7 days in children or
• Doxycycline 100 mg PO BID for 7 days in patients >45 kg or 2 mg/kg/dose PO q12h for 7 days in patients <45 kg and older than 8 years ^[3]