Supervisors info:
Γεωργία Βρυώνη,Αναπληρώτρια καθηγήτρια ,Ιατρική Σχολή ΕΚΠΑ
Δημήτριος Ρηγόπουλος, Καθηγητής, Ιατρική Σχολή ΕΚΠΑ
Σταμάτης Γρηγορίου,Επίκουρος Καθηγητής,Ιατρική Σχολή ΕΚΠΑ
Summary:
Objective: Demodex mites are obligatory human ectoparasites of the hair follicles and sebaceous glands, typically found on face and scalp. All cutaneous diseases caused by Demodex mites are clubbed under the term “demodicosis”. Their potential role as causative agents in the pathogenesis of human skin disorders (especially rosacae) causes continued speculation. The aim of the present study was to investigate the Demodex prevalence in patients with rosacea-like (rosaceiform) dermatitis, who were admitted to “Andrea Syggros” Hospital of Cutaneous and Venereal Diseases.
Materials and Methods: During the period 2015-2018, 829 patients with rosacea disease (914 specimens) were included in the study. For the determination of density of Demodex spp., non-invasive standard, light microscopy of skin scrap method was applied. Detection of ≥5 per optical field (magnification X400) Demodex spp. was considered positive.
Results: A total of 941 skin samples were taken over a 4-year period (2015-2018) from 829 patients with a rosacea-like disease. Seventy-six patients had more than one sample. Totally, from the 941 samples, 272 were taken from men and 669 from women. Demodex mites were found in 514 samples: 362 (54%) from women and 152 (56%) from men. No statistical significance was found in relation to gender and year of discovery. Then a re-analysis was made in relation to the patients. So, in 76 patients with more than one specimen, only the 1st sample was evaluated. Thus, in a total of 829 patients with a rosacea-like disease, 446 (54%) had a positive test result for Demodex (311 women, 53.7%, and 135 men, 54%). Seasonal distribution had an average 54% (range from 48 to 60%). Again, no statistical significance was found in relation to gender or time of the year. Regarding treatment, Demodex tested positive patients were treated with topical metronidazole for one month. In the follow-up, only 23 patients (23/76, 30%) had a negative result in microscopic examination for Demodex, rather indicating co-existence and not a truly pathogenic role of the parasite in the manifestations of rosacea disease.
In conclusions, for the years 2015-2018, it appears that a significant percentage of patients with a rosacea-like disease (54%, 446/829) showed “demodicosis”. The percentage was similar in men and women, with a similar appearance in different years of the study, as well as in the different seasons of the years. More data are needed, as well as studies with a control group of patients, in order to find a possible correlation between the existence of Demodex and cutaneous diseases of the face.
