Rosacea is a chronic inflammatory skin condition that is well-documented in light phototypes and less frequently reported in individuals with darker skin. Dermoscopy can be useful for the detection of the early features of rosacea that may not be visible clinically in dark phototypes. Our study aimed to describe dermoscopic features of rosacea in dark phototypes and compared them with those in light phototypes. A total of 206 patients with a clinical diagnosis of rosacea, confirmed or not by histopathology, were included over a 4-year period at Ibn Sina University Hospital in Rabat. We divided patients into two groups: light phototypes (Fitzpatrick I-III) and dark phototypes (IV-VI). Dermoscopic features terminology was chosen from the International Dermoscopy Society Consensus. A p-value of <.05 was considered statistically significant. Dark phototypes represented 68.4% of the study and were significantly older than light phototypes (p<.001). The erythematotelangiectatic subtype was the most common in both groups, followed by the papulopustular and phymatous subtypes. The phototype was significantly associated with both erythematotelangiectatic (p<.001) and papulopustular (p<.001) forms. Concerning dermoscopy, pigmented areas were more prevalent in dark phototypes (p=0.003), whereas orange structureless areas (p=0.027) and crusts (p=0.035) were found predominantly in light phototypes. 

In 39% of dark phototypes, erythema was undetectable clinically but vascular patterns and pigmented areas were seen with dermoscopy. We also found that 13.8% of dark phototypes presented pustules inapparent clinically with a significant association (p <.001).These findings highlight the importance of dermoscopy in detecting vascular structures,pigmentation, and pustules, particularly in darker skin where clinical assessment alone may be insufficient. In the papulopustular subtype, dermoscopy can reveal non-visible pustules, guiding the treatment with cyclines. Despite limitations including its monocentric design and the inclusion of treated patients, this study provides the largest comparative dermoscopic evaluation of rosacea across diverse phototypes to date.

Kenza Khachani has completed her PHD at the age of 27 years from Mohamed V University, Morocco. She is actually working at the dermatology department of Mohamed V University, Rabat, Morocco.