Topical brimonidine for the management of facial erythema in rosacea: a histological, histometric, and immunohistochemical study.

BACKGROUND: Facial erythema in rosacea is a troublesome embarrassing presentation with limited options of treatment. Daily brimonidine gel was shown to be an effective modality of treatment. Being unavailable in Egypt and the scarcity of objective evaluation of its therapeutic effect motivated the search for other alternatives. OBJECTIVE: To evaluate the use and effectiveness of topical brimonidine eye drops for the management of facial erythema in rosacea with the aid of objective assessment. METHODS: The study was conducted on 10 rosacea patients presented with facial erythema. Brimonidine tartrate eye drops 0.2% were applied twice daily for 3 months on areas of red facial skin. Punch biopsies were obtained before and after 3 months of treatment. Routine hematoxylin and eosin (H&E) staining as well as CD34 immunohistochemical staining were performed for all biopsies. Sections were examined to detect the changes in the count and the surface area of blood vessels. RESULTS: Evaluation of clinical results showed good improvement of facial redness at the end of treatment (55-75%). Only 10% of subjects expressed rebound erythema. H&E and CD34 stained sections showed an increased count of dilated dermal blood vessels, which decreased significantly after treatment in count and surface area (P = 0.005, and P = 0.004, respectively). CONCLUSION: Topical brimonidine eye drops proved to be effective in managing facial erythema in rosacea, providing an available and cheaper alternative to brimonidine gel. The study improved the subjective evaluation in the context of objective assessment of treatment efficacy.

Misbalanced CXCL12 and CCL5 Chemotactic Signals in Vitiligo Onset and Progression.

Generalized nonsegmental vitiligo is often associated with the activation of melanocyte-specific autoimmunity. Because chemokines play an important role in the maintenance of immune responses, we examined chemotactic signatures in cultured vitiligo melanocytes and skin samples of early (≤2 months) and advanced (≥6 months) vitiligo. Analysis showed that melanocytes in early lesions have altered expression of several chemotaxis-associated molecules, including elevated secretion of CXCL12 and CCL5. Higher levels of these chemokines coincided with prominent infiltration of the skin with antigen presenting cells (APCs) and T cells. Most of the intralesional APCs expressed the CD86 maturation marker and co-localized with T cells, particularly in early vitiligo lesions. These observations were confirmed by in vivo animal studies showing preferential recruitment of APCs and T cells to CXCL12- and CCL5-expressing transplanted melanocytes, immunotargeting of the chemokine-positive cells, continuous loss of the pigment-producing cells from the epidermis, and development of vitiligo-like lesions. Taken together, our studies show that melanocyte-derived CXCL12 and CCL5 support APC and T-cell recruitment, antigen acquisition, and T-cell activation in early vitiligo and reinforce the role of melanocyte-derived CXCL12 and CCL5 in activation of melanocyte-specific immunity and suggest inhibition of these chemotactic axes as a strategy for vitiligo stabilization.