Does Frequency Of Demodicosis Increase With Using Topical Drug And Cosmetics In Facial Dermatoses?

INTRODUCTION: This study aims to investigate whether topical drugs and cosmetic products in dermatological diseases in the facial area increase Demodex infestation and to determine the associated risk factors.
METHODS: This cross-sectional study included 193 patients with facial involvement and 102 healthy volunteers who applied to the dermatology outpatient clinic between January 2014 and December 2015. Demographic data, topical medication use, cosmetic product preferences, and facial cleansing habits were recorded. Demodex spp. samples were obtained from five face areas by the standard superficial skin biopsy method, and microscopic examination was performed.
RESULTS: The mean age of Demodex positive patients (36.84±16.4 years) was significantly higher than negative patients (29.84±13.46 years). Demodex positivity was higher in males (64.9%) than females (44.7%) (p=0.008). Among the diseases, the highest Demodex positivity was found in seborrhoeic dermatitis (70%) and rosacea (66.25%) (p=0.005). Among topical products, the highest Demodex positivity was observed in corticosteroid users (70.37%) and the lowest in tetracycline users (18.18%). In multivariate analysis, male gender (OR=2.27), increasing age (OR=1.38/decad), high body weight (OR=1.17/5kg), rosacea (OR=3.62), seborrheic dermatitis (OR=4.28), topical corticosteroid use (OR=3.87), and face washing with water only (OR=2.31) were determined as independent risk factors.
DISCUSSION AND CONCLUSION: Topical corticosteroids, sunscreens, and moisturisers have been shown to increase Demodex infestation in facial dermatological diseases. A strong positive correlation was found between disease severity and Demodex density. Non-irritating cleansing products should be recommended for patients with facial dermatological diseases.

Keywords: Demodex spp., rosacea, seborrheic dermatitis, cosmetics, topical drugs