Discreet follicular scales, scalp symptoms, and pruritus are associated with rosacea and demodicosis conditions and warrant close clinical examination for the accurate diagnosis of patients with nonspecific skin complaints, according to a study published in Acta Dermato-Venereologica.

The investigators of this retrospective study sought to characterize the diagnostic importance of nonspecific symptoms, such as discreet facial follicular scales, dandruff, scalp folliculitis, and facial or scalp pruritus, which are less frequently associated with the skin conditions papulopustular rosacea and demodicosis. The investigators further examined the relationship of scalp and ocular involvement with Demodex density measurements.

The study sample included 844 participants with symptoms suggestive of papulopustular rosacea (n=254) or demodicosis (n=590). In 2002, the investigators began to collect data on patient demographics, clinical diagnosis, symptoms, ocular involvement, and recent treatment for rosacea or demodicosis. Scalp involvement was analyzed in a subgroup of patients (n=488) starting in 2005. A second control subgroup (n=490) was studied for the same scalp symptoms in order to limit confounding. In all patients, 2 consecutive skin surface biopsies were used to collect the top layers of skin and follicular content. The number of Demodex mites found on the lashes was reported in patients with ocular involvement.

Of 844 patients, 805 (95%) reported complaints that were localized to the face, 22 (3%) reported scalp involvement, and 17 (2%) reported ocular involvement. In 37 out of 39 patients with primary scalp or ocular involvement, clinical examination revealed facial demodicosis, even where facial skin appeared healthy. Discreet follicular scales were observed in 93% of the total cohort, whereas commonly associated vascular symptoms were reported in 80% of the cohort (P <.001). 

Pruritus was diagnosed in 130 (15%) patients and was prevalent in 24% of the scalp involvement subgroup. Of the subgroup participants, 106 (22%) had pruritus localized to the scalp, 15 (3%) had pruritus localized to the face, and 2 (0.4%) reported pruritus of the eyes. Of the total cohort, 321 (38%) patients reported scalp symptoms, which were prevalent in 50% of the scalp involvement subgroup. Ocular involvement was reported in 180 (21%) patients, which was significantly higher in patients with symptoms suggestive of rosacea than in those with demodicosis (28% vs 19%; P =.004). Most (161 of 180) patients with ocular involvement were examined for Demodex mites, which were found in the eyelashes of 147 (91%) patients.

The high frequency at which discreet follicular scales were associated with rosacea and demodicosis provides evidence of the diagnostic value of close clinical examination of follicular scales in patients with skin conditions. Pruritus and symptoms localized to the scalp, which are frequently associated with ocular involvement, likely represent more advanced stages of rosacea and demodicosis and should be carefully considered in making a clinical diagnosis.

Disclosures: Fabienne M. N. Forton works as a consultant for Galderma.

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Reference

Forton FMN, De Maertelaer V. Rosacea and demodicosis: little-known diagnostic signs and symptoms [published online September 18, 2018.] Acta Derm Venereol. doi:10.2340/00015555-3041