A 20-year-old man on oral tetracycline for 8 months for facial acne develops multiple superficial pustules clustered around the nose and chin, resistant to continuing therapy. Bacterial culture from a pustule grows Klebsiella species. The most appropriate next step is:

• A Increase the dose of tetracycline
• B Stop the tetracycline and treat with isotretinoin or culture-directed antibiotics ✓
• C Add topical benzoyl peroxide and continue antibiotics
• D Start oral antifungal therapy with itraconazole

Explanation

This is gram-negative folliculitis, a recognised complication of long-term broad-spectrum antibiotic therapy for acne, caused by overgrowth of Enterobacteriaceae such as Klebsiella, Proteus and Escherichia coli. Treatment requires stopping the offending antibiotic and giving isotretinoin (highly effective, often curative) or antibiotics guided by culture sensitivity. Escalating tetracycline worsens the selection pressure, benzoyl peroxide alone will not clear established gram-negative folliculitis, and antifungals address Malassezia folliculitis, a different entity.

Reference: Fitzpatrick's Dermatology, 9th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.