Pulsed-dye laser as an effective treatment for recalcitrant granulomatous rosacea and a potential regulator of CXCL9 expression.

Granulomatous rosacea (GR) is a rare and distinct variant of rosacea. We report three cases of recalcitrant GR successfully treated with pulsed-dye laser (PDL) and provide experimental evidence supporting its potential as a treatment option. PDL treatment demonstrated remarkable efficacy in the three clinical cases, despite their resistance to conventional therapies. Chemokine ligand 9 (CXCL9), a key chemokine involved in inflammation and granuloma formation, was found to be increased in skin sections from all three patients. In vitro experiments using human monocytes and dermal fibroblasts demonstrated that PDL treatment significantly reduced CXCL9 expression in fibroblasts. These findings suggest that PDL may modulate CXCL9 secretion in fibroblasts, potentially limiting the recruitment of immune cells to the lesion. Although further research is needed to fully understand the precise mechanisms underlying the role of CXCL9 in GR, PDL may be a promising therapeutic approach for refractory GR.