Study of topical explores role of bacteria

New Orleans - Bacteria play a role in rosacea development and that pathway should be further explored to develop novel agents to treat inflammatory lesions, says James Leyden, M.D., professor emeritus at the University of Pennsylvania School of Medicine, Philadelphia.

Dr. Leyden notes results of a study he conducted which found that administration of benzoyl peroxide 5 percent/clindamycin 1 percent topical gel was more effective than placebo in clearing rosacea lesions. He presented the findings at the 63rd Annual Meeting of the American Academy of Dermatology (AAD) here. That study was published in 2004 in the International Journal of Dermatology.

"The standard belief about rosacea is that there are stages of progression," Dr. Leyden tells Dermatology Times. "People have been trying to link the signs and symptoms into one pathophysiology. The other school of thought is that there are multiple pathways."

The signs and symptoms of rosacea are often not specific, so dermatologists may need to consider other diagnoses such as acne, contact dermatitis or eczema.

Dermatologists advise patients with rosacea to avoid triggers such as spicy foods, alcohol, extreme heat or cold, sunlight, stress and strenuous exercise to keep their symptoms under control.

Research study Dr. Leyden opted to choose an agent with antimicrobial properties to see if it alleviated the lesions associated with rosacea. The 12-week, double-blind, placebo-controlled, randomized, prospective, parallel-group study in 52 patients used baseline and end-of-treatment photographs to measure improvement in the patients. The mean percentage reduction in papules and pustules from baseline to the end of treatment was 71.3 percent in the benzoyl peroxide/clindamycin (BP/C) group, consisting of 26 patients, compared to 19.3 percent in the placebo group, which also had 26 patients. Patients enrolled in the study had at least 15 inflammatory lesions, characterized as a bad phase of rosacea. Patients received once-daily treatment with BP/C or standard treatment for 12 weeks.

At week 12, patients treated with BP/C were rated as "clear or nearly clear" (7.7 percent) while no patients receiving the placebo were rated clear or nearly clear at the end of the treatment period. Severity scores for erythema, papules/pustules, and flushing/blushing declined more with BP/C than with placebo. Application site reactions were reported in four patients (14.8 percent) of patients in the BP/C arm of the study.

Role of bacteria "The concept that I wanted to explore was if bacteria play an important role in the papular/pustular phase of rosacea," Dr. Leyden says. "For such a common problem, the pathophysiology has been seriously understudied."

There is a need for better topical agents to treat rosacea, Dr. Leyden adds. He contends that the BP/C combination would likely be more efficacious in clearing lesions than current available treatments.

Oral antibiotics that are typically prescribed include tetracycline, minocycline, erythromycin and doxcycline. Side effects of the oral agents include stomach upset, nausea, photosensitivity and yeast infections. A topical agent such as metronidazole can be applied to the skin to treat rosacea.

Approaching rosacea Dr. Leyden stresses that researchers need to approach rosacea as a condition that has multiple pathways in order that novel treatment agents emerge.