Demodex and rosacea: Is there a relationship?

Abstract

Purpose:The objective of the study is to compare the frequency of Demodex on the eyelash follicle of patients with rosacea and referents without rosacea or ophthalmological disorders.Methods:This is a comparative, open, observational, and cross-sectional study that included 41 patients diagnosed with rosacea and 41 referents without rosacea diagnosis or ophthalmic alterations. The individuals underwent a slit-lamp examination in which two eyelashes per eyelid were removed with fine forceps. The presence of Demodex was sought by direct visualization under a light microscope. The results were expressed as “positive” when at least one mite on one lash was found and “negative” when no mite was identified. Chi-square test was used to compare the presence of mites in both groups.Results:Eighty-two study individuals (45 females and 37 males) were included, of which 41 patients were diagnosed with rosacea and 41 were without rosacea or ophthalmic alterations. The average mean age was 37 years with a minimum of 19 and a maximum of 87 years. Of the 41 patients with rosacea, 31 had erythematotelangiectatic rosacea and 10 had papulopustular rosacea. There were no patients with phymatous or ocular rosacea. The presence of Demodex was found in 32 patients: 24 patients with rosacea diagnosis (16 of the erythematotelangiectatic subtype and 8 of papulopustular subtype) and 8 patients without rosacea or ophthalmic alterations (P ≤ 0.001).Conclusion:Rosacea was found to be a statistically significant risk factor for Demodex infestation in eyelashes, irrespective of age and sex, with a higher prevalence in papulopustular variety.

Effect of recombinant bovine basic fibroblast growth factor gel on repair of rosacea skin lesions: A randomized, single‑blind and vehicle‑controlled study

“…A close association of Demodex mite with facial dermatitis was previously observed ( 5 ). Demodex mite is a microscopic ectoparasite with a slender body (length, 0.3–0.4 mm), which mainly feeds off epidermal cells and sebum components.…”

“…High infection rates of Demodex have recently been observed in patients with rosacea; the pathogenetic mechanisms of the disease mainly comprise mechanical stimulation, secondary bacterial infection and immune pathology ( 5 ). It has also been suggested that ornidazole-based therapy is highly effective in the treatment of mite folliculitis ( 6 ).…”

“…The human body has characteristics of high infectivity, and low and conditional pathogenicity to Demodex mites ( 6 , 7 ). The infestation rate of Demodex mite is also high in rosacea patients ( 5 ). If ornidazole treatment is used alone, untreated lesions tend to aggravate and result in ulceration and scar formation ( Fig.…”

Assessment of Frequency of Rosacea Subtypes in Patients With Rosacea

“…The pooled proportions of ETR, PPR, PhR, and ocular rosacea among 9190 patients with rosacea, based on 39 studies (eTable 2 in the Supplement), were ETR: 56.7% (95% CI, 51.4%-62.0%; I 2 , 95.9%) (Figure 2), PPR: 43.2% (95% CI, 38.8%-47.6%; I 2 , 94.0%) (Figure 3), PhR: 7.4% (95% CI, 6.1%-8.9%; I 2 , 81.4%) (Figure 4), and ocular rosacea: 11.1% (95% CI, 6.7%-16.3%, I 2 , 98.1%) (Figure 5). The proportions of ETR and PPR appeared to be similar for male and female patients; the proportion of ETR was 58.3% (95% CI, 25.8%-87.2%) for men and 65.5% (95% CI, 41.8%-85.8%) for women based on 3 studies . Papulopustular rosacea was reported for 29.6% (95% CI, 10.5%-53.4%) of men and 34.6% (95% CI, 13.7%-59.3%) of women.…”

Oral Ivermectin for the Treatment of Rosacea-Associated Blepharitis: Case Report

“…[8,9] Studies have found significant correlations between facial rosacea, eyelid inflammation, and Demodex infestations. [10,11] These studies provide some answers but leave the question of whether targeted treatment of Demodex would improve the disease course of cutaneous and ocular manifestations of rosacea.…”