Topical metronidazole maintains remissions of rosacea.

BACKGROUND Rosacea is a chronic skin disease that requires long-term therapy. Oral antibiotics and topical metronidazole successfully treat rosacea. Because long-term use of systemic antibiotics carries risks for systemic complications and adverse reactions, topical treatments are preferred. OBJECTIVE To determine if the use of topical metronidazole gel (Metrogel) could prevent relapse of moderate to severe rosacea. DESIGN A combination of oral tetracycline and topical metronidazole gel was used to treat 113 subjects with rosacea (open portion of the study). Successfully treated subjects (n = 88) entered a randomized, double-blind, placebo-controlled study applying either 0.75% topical metronidazole gel (active agent) or topical metronidazole vehicle gel (placebo) twice daily (blinded portion of the study). SETTING Subjects were enrolled at 6 separate sites in large cities at sites associated with major medical centers. SUBJECTS One hundred thirteen subjects with at least 6 inflammatory papules and pustules, moderate to severe facial erythema and telangiectasia entered the open phase of the study. Eighty-eight subjects responded to treatment with systemic tetracycline and topical metronidazole gel as measured by at least a 70% reduction in the number of inflammatory lesions. These subjects were randomized to receive 1 of 2 treatments: either 0.75% metronidazole gel or placebo gel. INTERVENTIONS Subjects were evaluated monthly for up to 6 months to determine relapse rates. MAIN OUTCOME MEASURES Inflammatory papules and pustules were counted at each visit. Relapse was determined by the appearance of a clinically significant increase in the number of papules and pustules. Prominence of telangiectases and dryness (roughness and scaling) were also observed. RESULTS In the open phase, treatment with tetracycline and metronidazole gel eliminated all papules and pustules in 67 subjects (59%). The faces of 104 subjects (92%) displayed fewer papules and pustules after treatment, and 82 subjects (73%) exhibited less erythema. In the randomized double-blind phase, the use of topical metronidazole significantly prolonged the disease-free interval and minimized recurrence compared with subjects treated with the vehicle. Eighteen (42%) of 43 subjects applying the vehicle experienced relapse, compared with 9 (23%) of 39 subjects applying metronidazole gel (P<.05). The metronidazole group had fewer papules and/or pustules after 6 months of treatment (P<.01). Relapse of erythema also occurred less often in subjects treated with metronidazole (74% vs 55%). CONCLUSION In a majority of subjects studied, continued treatment with metronidazole gel alone maintains remission of moderate to severe rosacea induced by treatment with oral tetracycline and topical metronidazole gel.