Action of isotretinoin in acne rosacea and gram-negative folliculitis.

Good to excellent clinical results have been obtained in the treatment of severe inflammatory acne (acne conglobata, acne fulminans, and acne conglobata with hidradenitis and dissecting cellulitis of the scalp) with orally administered isotretinoin (13-cis-retinoic acid). Similar promising results have been obtained in patients with severe rosacea and gram-negative folliculitis. Isotretinoin probably has multiple modes of action, including (1) inhibition of sebaceous gland activity, (2) inhibition of the growth of Propionibacterium acnes within the follicle, although the retinoid is not antibacterial, (3) inhibition of inflammation, and (4) alteration of the pattern of keratinization within the follicle, as demonstrated by light and ultrastructural studies.