Dermoscopy of papulopustular rosacea and comparison of dermoscopic features in patients with or without concomitant Demodex folliculorum

Abstract

Background. The dermoscopic findings of papulopustular rosacea include tiny papules and pustules, follicular plugs and follicular dilatation. Demodex tails and Demodex follicular openings are dermoscopic indicators that are mainly found in primary demodicosis and, less frequently, in rosacea. Aim. To describe the dermoscopic features of papulopustular rosacea and to investigate the differential dermoscopic features between patients with and without concomitant Demodex infestation. Methods. We conducted a prospective study of patients with almost-clear, mild or moderate papulopustular rosacea. For each patient, dermoscopic images were taken and a standardized skin surface biopsy was performed. Results. In this group of 60 patients, the most frequent dermoscopic findings were yellow dots, vascular polygons and follicular scales. Patients with moderate rosacea had more Demodex follicular openings compared with patients with mild rosacea (P = 0.02), while patients with mild rosacea had a higher frequency of follicular scales than did patients with almost-clear rosacea (P = 0.01). Patients with moderate rosacea had higher rates of Demodex follicular openings (P = 0.02), follicular scales (P < 0.001), follicular annular pigmentation (P = 0.001) and follicular pustules (P < 0.001) compared with patients with almost-clear rosacea. No significant dermoscopic differences were observed between patients with and without concomitant Demodex infestation. Conclusions. Papulopustular rosacea has specific dermoscopic findings. In our opinion, dermoscopy is not sufficient by itself for the diagnosis of Demodex proliferation in rosacea.

Summarization and comparison of dermoscopic features on different subtypes of rosacea

“…This difference might be caused by the sample size. Additionally, follicular findings were more prominent in PPR compared with ETR, consistent with previous reports [12,15,22] . A previous study indicated that follicular scales (included as yellow scales in the present study) should be regarded as a diagnostic criterion for rosacea since they were statistically correlated with persistent erythema [23] .…”

“…Most plugs were yellow and corresponded to keratotic material and/or sebum in dilated follicular infundibula. [ 12 ] Lallas [ 10 ] suggested that the presence of orange-yellowish areas implied granulomatous rosacea (GR). This feature was detected for all subtypes in our current study, indicating that some GR cases might experience missed or delayed diagnosis.…”

“…Rosacea diagnoses are usually performed by medical history and physical examinations, which might be difficult due to the clinical manifestations’ similarities to several skin conditions. Dermoscopy, a non-invasive technique that allows real-time and in vivo examination of various skin diseases, has been used to distinguish rosacea from its visual analogs [8–19,15,21,22] . Therefore, a comprehensive understanding of the dermoscopic features of rosacea is crucial to guide clinical practice.…”

“…Follicular plugs were also evident in PHR. Most plugs were yellow and corresponded to keratotic material and/or sebum in dilated follicular infundibula [12] . Lallas [10] suggested that the presence of orange-yellowish areas implied granulomatous rosacea (GR).…”

“…The definitions of dermoscopic features were the same as previously described. [ 10 – 12 , 14 – 20 ]…”