Gram Negative

 

Folliculitis

 

 

Gram-negative folliculitis may occur in patients with pre-existing acne vulgaris treated with long-term oral antibiotics, especially the tetracyclines. Patients usually give a history of initial success with oral tetracyclines followed by a worsening of their acne. Gram-negative folliculitis may appear as either papulopustules concentrated around the nose or as deep-seated nodules. Culture of these lesions may reveal Enterobacter, Klebsiella, or Escherichia in the papulopustules or Proteus in the nodules. An appropriate antimicrobial agent with adequate Gram-negative coverage should be used. In recalcitrant cases, Gram-negative folliculitis improves with oral isotretinoin for 4 to 5 months. Gram-negative bacteria require a moist environment for survival and the drying action of isotretinoin kills the bacteria. In some cases, an oral cephalosporin may be given for 2 weeks in combination with isotretinoin