Dermoscopy of rosacea: A cross-sectional study comparing dark and light phtotypes

This study investigates the dermoscopic features of rosacea in different skin phototypes, particularly focusing on underreported presentations in darker skin. A cross-sectional analysis was conducted on 206 patients with clinically diagnosed rosacea at Ibn-Sina University Hospital over four years. Patients were categorized into light (Fitzpatrick I–III) and dark (Fitzpatrick IV–VI) phototypes. Dermoscopic variables were selected based on International Dermoscopy Society criteria.

The mean patient age was 45.8 years, with a predominance of women (86.9%) and dark phototypes (68.4%). Erythematotelangiectatic rosacea was the most common subtype across both groups. Dark phototypes showed a significantly higher mean age and were more likely to present pigmented areas (p=0.003). Light phototypes more commonly showed orange structureless areas (p=0.027) and crusts (p=0.035). Dermoscopy showed features non-visible clinically. In 39% of dark phototypes, erythema was undetectable clinically but vascular patterns and pigmented areas were seen with dermoscopy. Pustules were observed in 18.4% of dark and 23.1% of light phototypes. We found that 13.8% of dark phototypes presented pustules inapparent clinically with a significant association(p<0.001).