Treatment of Bacterial Sore on Outer Lip with Bactroban (Mupirocin) Ointment
Bactroban (mupirocin) 2% ointment is appropriate and effective for treating bacterial sores on the outer lip, applied three times daily for 3-5 days, though it should not be used on mucosal surfaces inside the mouth. 1
Application Guidelines
Apply a small amount of mupirocin 2% ointment to the affected area on the outer lip three times daily. 1 The treatment area may be covered with gauze dressing if desired, though this is optional for lip lesions. 1
- Re-evaluate the patient if no clinical response occurs within 3-5 days, as this may indicate the need for alternative therapy or systemic antibiotics. 1
- The outer lip (vermillion border and skin) is an appropriate site for mupirocin ointment application, as it is external skin rather than mucosal tissue. 1
Critical Safety Considerations
Do not apply mupirocin ointment to mucosal surfaces inside the mouth, as the polyethylene glycol-based formulation is not designed for mucosal use. 1 For lip care in conditions requiring mucosal protection (such as severe blistering disorders), white soft paraffin ointment should be used instead. 2
- Discontinue treatment immediately if irritation, severe itching, or rash develops, and consider alternative therapy. 1
- Avoid contact with the eyes during application. 1
Clinical Efficacy for Skin Infections
Mupirocin demonstrates excellent efficacy for superficial bacterial skin infections caused by Staphylococcus aureus and streptococci. 3, 4, 5 Clinical trials show:
- Clinical cure or marked improvement rates of 80-97% for primary skin infections, including impetigo and infected wounds. 5, 6
- Bacterial eradication rates exceeding 90% for S. aureus and beta-hemolytic streptococci. 5, 6
- Mupirocin is as effective as oral antibiotics (cloxacillin, dicloxacillin, erythromycin) for localized infections. 3
When Systemic Antibiotics Are Required Instead
Do not use mupirocin as monotherapy if the infection shows:
- Signs of systemic toxicity (fever, malaise, lymphadenopathy). 7
- Extensive or widespread involvement beyond a localized sore. 7
- Purulent cellulitis or abscess formation requiring drainage. 7
- Lack of improvement after 3-5 days of topical therapy. 1
In these scenarios, oral beta-lactam antibiotics targeting streptococci or anti-staphylococcal agents are required. 7
Common Pitfalls to Avoid
- Do not use the polyethylene glycol-based mupirocin ointment inside the mouth—this formulation is specifically contraindicated for mucosal surfaces. 1 A separate paraffin-based formulation (Bactroban Nasal) exists for intranasal use only. 1
- Do not use in patients with moderate to severe renal impairment if there are open wounds or damaged skin, as polyethylene glycol can be absorbed and is renally excreted. 1
- Prolonged use may lead to overgrowth of nonsusceptible organisms including fungi, so limit treatment duration appropriately. 1