Can mupirocin (mupirocin) ointment be used to treat bacterial infections on the lips?

Can Mupirocin Ointment Be Used on Lips?

Yes, mupirocin 2% ointment can be used to treat bacterial infections on the lips, such as bacterial cheilitis, with excellent activity against Staphylococcus aureus (including MRSA) and Streptococcus species, which are the common causative organisms. 1

Key Indication for Lip Infections

• Mupirocin is specifically effective for bacterial cheilitis caused by susceptible strains of S. aureus and S. pyogenes, the predominant pathogens in superficial skin infections including those affecting the lips. 1
• The medication demonstrates excellent antimicrobial activity against these organisms, making it appropriate for localized bacterial infections of the lips. 2, 1

Critical FDA Warning About Mucosal Surfaces

However, there is an important caveat: mupirocin ointment is NOT formulated for use on mucosal surfaces. 3

• The FDA label explicitly states that "mupirocin ointment is not formulated for use on mucosal surfaces." 3
• This means you should apply mupirocin only to the external lip surface (vermillion border and skin), avoiding the inner mucosal surfaces of the mouth. 3
• The polyethylene glycol vehicle in standard mupirocin ointment can be absorbed from damaged skin and is excreted by the kidneys, which is particularly concerning in patients with moderate to severe renal impairment. 3

Application Protocol

• Apply a small amount of mupirocin 2% ointment directly to the affected area of the external lip twice to three times daily. 2, 4
• Treatment duration should be 5-10 days, with most guidelines recommending 5 days for localized infections. 2, 4, 1
• Avoid contact with the eyes and limit application to external surfaces only. 3

When to Reassess or Switch to Systemic Therapy

• If the bacterial cheilitis shows no improvement within 3-5 days, reassess and consider systemic antibiotics. 4, 1
• Switch to oral antibiotics if signs of systemic involvement exist (fever, extensive cellulitis), the infection is worsening despite topical therapy, or the patient is immunocompromised. 2, 1
• For severe or extensive infections with systemic signs, systemic antibiotics effective against both MRSA and streptococci are necessary. 1

Important Limitations and Pitfalls

• Prolonged use should be avoided to prevent development of bacterial resistance and skin sensitization. 4, 1, 3
• If the cheilitis is associated with an abscess, incision and drainage is the primary treatment, with mupirocin serving only as adjunctive therapy. 1
• Stop the medication immediately if irritation, severe itching, or rash occurs, and contact your healthcare provider. 3
• For recurrent bacterial cheilitis, address underlying factors such as angular cheilitis, lip licking habits, or chronic dryness to prevent recurrence. 1

Bottom Line

Mupirocin can be safely and effectively used on the external surfaces of the lips for bacterial infections, but must be kept away from mucosal surfaces inside the mouth. Limit treatment to 5-10 days and reassess if no improvement occurs within 3-5 days.