Brimonidine 0.33% for Rosacea-Related Facial Erythema

This prospective, two-phase clinical study was designed to evaluate the acute and short-term effects of 0.33% brimonidine gel on persistent facial erythema associated with rosacea. The study included an acute phase using a split-face, randomized, placebo-controlled methodology, followed by a one-month open-label phase.

In the acute phase, each participant received brimonidine gel on one half of the face and a placebo gel on the opposite side. The assignment of treatment sides was randomized for each participant. Erythema measurements were obtained at baseline (0 hour) and again one hour after application to assess the immediate vasoconstrictive effect of brimonidine. Dermoscopic imaging was performed to evaluate vascular morphology, including erythema intensity, vascular density, vessel caliber, and the area of involvement. These dermoscopic parameters were scored using predefined semi-quantitative scales developed for this study.

In the second phase, all participants applied 0.33% brimonidine gel once daily to the entire face for one month. At the end of the one-month period, erythema measurements and dermoscopic evaluations were repeated before and one hour after application to determine whether the acute response to brimonidine changed with continuous daily use. Patient-reported outcomes, including burning, stinging, and other treatment-related symptoms, were also recorded during both phases.

Objective erythema was quantified using a biophysical measurement device (erythema index), which provided standardized and reproducible assessments of skin redness. The use of both biophysical measurements and dermoscopic visualization allowed for a comprehensive evaluation of the drug's clinical and vascular effects.

No investigational new drug application (IND) was involved, and the product used was a commercially available formulation of brimonidine. All study procedures were performed under ethics committee approval, and written informed consent was obtained from all participants.

Inclusion criteria

• Adults aged 18 years or older
• Clinical diagnosis of erythematotelangiectatic rosacea (ETR) according to the National Rosacea Society (NRS) diagnostic criteria
• Presence of persistent facial erythema consistent with ETR
• Symmetrical facial involvement adequate for split-face assessment
• No more than two inflammatory facial lesions at screening
• Ability and willingness to comply with all study procedures, including acute Day 1 assessments and the 1-month follow-up visit
• Willingness to apply topical brimonidine gel daily during the 1-month period and to avoid initiating new rosacea treatments during the study
• Provision of written informed consent

Exclusion criteria

• Individuals younger than 18 years.
• Presence of three or more inflammatory facial lesions.
• Prior use of BT (brimonidine tartrate) for facial erythema.
• Use of topical or systemic treatments for rosacea or other dermatoses without completing the required washout period.
• Presence of other facial dermatoses
• Withdrawal of consent (the only discontinuation criterion)