eMedicine Specialties > Emergency Medicine > Infectious Diseases
Impetigo: Treatment & Medication
Updated: Sep 15, 2009
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Treatment
Emergency Department Care
The emerging resistance of S aureus to beta-lactams, macrolides, and even mupirocin requires consideration of the prevalence of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) in the locale of the patient. Treatment of bullous impetigo should now always consider this possibility. Trimethoprim-sulfamethoxazole, clindamycin, and rifampin all retain sensitivity in the vast majority of CA-MRSA strains.
- Wound cleaning with gentle abrasion is indicated. Deep abrasive scrubbing is not required.
- Topical mupirocin is adequate treatment for single lesions of nonbullous impetigo or small areas of involvement. A 7-day course is usually standard, although a few large studies have been performed to verify this as the most effective approach.
- Systemic antibiotics are indicated for extensive involvement or for bullous impetigo.
- If there are large areas of involvement resulting in denuded skin from ruptured bullae, then adequate fluid resuscitation is indicated with intravenous rehydration fluid at a volume and rate similar to standard volume replacement for burns.
- Early and appropriate treatment usually prevents scarring and localized spread.
- Good hygiene and hand washing should be encouraged. Household spread is common otherwise. If skin care is not reviewed with the patient, the chance of re-infection or persistent infection is high. Skin care details should include adjuvants to topical antibiotics. The easiest adjuvants to use for patients are the bleach bath (1 cup of bleach in a bathtub of water at a safe level and with supervision), mixing vinegar and water at a 1:4 ratio for rinsing the area, and chlorhexidine scrubs.
Consultations
The need for consultation is determined by the extent of involvement and the age of the patient. Neonates with bullous impetigo require a consultation with neonatology. Recurrent disease should trigger a specialist consult.
Medication
Antibiotics are the mainstay of therapy, but they should be done in isolation without the adjuvants discussed above.
The drug chosen must provide coverage against coagulase-positive S aureus and GABHS. In areas with high percentage of CA-MRSA, the empiric antibiotic choice should provide coverage for this possibility.
Topical antibiotics
These agents pose fewer potential problems than systemic antibiotics, but their use is reserved only for cases involving lesions that are small or few in number.
Mupirocin ointment (Bactroban)
DOC for few small lesions in absence of lymphadenopathy.
Adult
Apply to lesions tid for 5 d; clean lesions prior to application
Pediatric
Apply as in adults
None reported
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Prolonged use may result in growth of nonsusceptible organisms
Retapamulin (Altabax)
Topical antibiotic available as a 1% ointment. First of new antibiotic class called pleuromutilins. Inhibits protein synthesis by binding to 50S subunit on ribosome. Indicated for impetigo caused by Staphylococcus aureus or Streptococcus pyogenes.
Adult
Apply topically to affected site bid for 5 d
Pediatric
<9 months: Not established
>9 months: Apply as in adults
None known
Documented hypersensitivity
Pregnancy
C - Fetal risk revealed in studies in animals but not established or not studied in humans; may use if benefits outweigh risk to fetus
Precautions
May cause irritation at application site (1.4%); avoid application to eye area; keep out of reach of children
Systemic antibiotics
Therapy must cover all likely pathogens in the context of the clinical setting.
Cephalexin (Keflex)
First-generation cephalosporin that inhibits bacterial growth by inhibiting bacterial cell wall synthesis; bactericidal and effective against rapidly growing organisms forming cell walls. Primarily active against skin flora; typically used for skin-structure coverage and as prophylaxis in minor procedures. Does not cover MRSA.
DOC for cases involving large number of lesions, large areas of involvement, or regional lymphadenopathy.
Adult
250-500 mg PO qid for 7 d
Pediatric
25-50 mg/kg/d PO divided qid
Aminoglycosides increase nephrotoxic potential
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in renal impairment
Erythromycin (EES, Erythrocin, Ery-Tab)
DOC in penicillin- or cephalosporin-allergic patient. Inhibits RNA-dependent protein synthesis, possibly by stimulating dissociation of peptidyl tRNA from ribosomes, which inhibits bacterial growth. Does not cover MRSA.
Adult
250-500 mg PO qid for 7 d
Pediatric
30-50 mg/kg/d PO divided qid for 7 d
May increase toxicity of theophylline, digoxin, carbamazepine, and cyclosporine; may potentiate anticoagulant effects of warfarin; lovastatin or simvastatin increases risk of rhabdomyolysis
Documented hypersensitivity; hepatic impairment
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Resistance may exist in some areas (as many as 30% of cases); caution in liver disease; estolate preparations may cause cholestatic jaundice; GI adverse effects, including nausea and vomiting, are common (administer doses after meals); discontinue use if nausea, vomiting, malaise, abdominal colic, or fever occur
Dicloxacillin (Dycill, Dynapen)
Bactericidal antibiotic that inhibits cell wall synthesis. Used in treatment of infections caused by penicillinase-producing staphylococci; may be used to initiate therapy when staphylococcal infection suspected. Very effective but less well tolerated than cephalexin. Does not cover MRSA.
Adult
250 mg PO qid for 7 d
Pediatric
20-50 mg/kg/d PO divided qid for 7 d
Decreases efficacy of oral contraceptives; increases effects of anticoagulants; probenecid and disulfiram may increase levels
Documented hypersensitivity
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Monitor PT in patients taking anticoagulant medications; toxicity may increase in renal impairment
Clindamycin (Cleocin)
Semisynthetic antibiotic produced by 7(S)-chloro-substitution of 7(R)-hydroxyl group of parent compound lincomycin. Inhibits bacterial growth, possibly by blocking dissociation of peptidyl tRNA from ribosomes, causing RNA-dependent protein synthesis to arrest. Widely distributes in the body without penetration of CNS. Protein bound and excreted by the liver and kidneys.
Alternative therapy for S aureus resistant to erythromycin and MRSA. Used for treatment of serious skin and soft tissue staphylococcal infections. Also effective against aerobic and anaerobic streptococci (except enterococci).
Adult
300 PO q8h for 10 d
Pediatric
10-30 mg/kg/d PO divided q6-8h for 10 d
Increases duration of neuromuscular blockade induced by tubocurarine and pancuronium; erythromycin may antagonize effects of clindamycin; antidiarrheals may delay absorption of clindamycin
Documented hypersensitivity; regional enteritis; ulcerative colitis; hepatic impairment; antibiotic-associated colitis
Pregnancy
B - Fetal risk not confirmed in studies in humans but has been shown in some studies in animals
Precautions
Adjust dose in severe hepatic dysfunction; no adjustment necessary in renal insufficiency; associated with severe and possibly fatal colitis by allowing overgrowth of Clostridium difficile
More on Impetigo |
| Overview: Impetigo |
| Differential Diagnoses & Workup: Impetigo |
 Treatment & Medication: Impetigo |
| Follow-up: Impetigo |
| Multimedia: Impetigo |
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References
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Oranje AP, Chosidow O, Sacchidanand S, et al. Topical retapamulin ointment, 1%, versus sodium fusidate ointment, 2%, for impetigo: a randomized, observer-blinded, noninferiority study. Dermatology. 2007;215(4):331-40. [Medline].
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Further Reading
Keywords
impetigo, impetigo contagiosa, group A beta-hemolytic streptococci, GABHS, Staphylococcus aureus, bullous impetigo, impetigo bullosa, common impetigo, folliculitis, follicular impetigo, ecthyma, vesiculopustular infection
