• Prevalence of Demodex folliculorum infection in patients referred to the ‎Dermatology Clinic of Imam Reza Hospital in Tehran in 2019‎
  • Mohammad Hossein Hajali,1 Hamidreza Karbalaei-Musa,2 Mohamad Mohsen Homayouni ‎,3,*
    1. ‎Student research committee, AJA University of Medical Sciences, Tehran, Iran‎
    2. Student research committee, AJA University of Medical Sciences, Tehran, Iran‎
    3. Department of Parasitology and Mycology, School of Medicine, AJA University of Medical Sciences‏,‏‎ Tehran, ‎Iran


  • Introduction: One type of external human parasite is worm-shaped scabies called Demodex. ‎Demodex folliculorum and ‎Demodex brevis live in the hair follicles and sebaceous ‎glands of human skin and various mammals, respectively. The mentioned infection ‎should be studied from various clinical and epidemiological aspects in Iran. Therefore, ‎this study was designed and conducted to investigate the frequency of D. folliculorum ‎infection in patients referred to the Dermatology Clinic of Imam Reza Hospital in ‎Tehran.‎
  • Methods: Patients with symptoms and skin lesions such as rosacea, skin ‎redness, itching, ‎burning, scaling, and pustules were selected as the study group. After ‎obtaining ‎written informed consent from the subjects and providing the necessary explanations, ‎the ‎research questionnaire was completed to provide background information ‎including age, ‎education, employment status, history of skin diseases, and marital ‎status. To test for ‎Demodex contamination, surface skin chips were prepared, and the ‎samples were taken to the ‎laboratory for testing. Some of the skin chips were placed ‎on a clean microscope slide and clarified by ‎adding a drop of 10% potash solution to ‎one slide and a lactophenol solution to the other. After placing the other slide on top ‎of the sample slide, microscopic ‎observation was performed using objective lenses ‎with magnifications of 10, 4, and 40 times. ‎Demodex-positive cases were ‎photographed at the prepared magnifications and ‎identified by comparing the ‎morphological features and parameters described in the valid ‎sources.‎
  • Results: In this study, 100 patients referred to the Dermatology Clinic of Imam Reza Hospital in ‎‎Tehran with clinical suspicion of infection as diagnosed by a dermatologist, were ‎‎randomly included in the study. The mean age (standard deviation) of the patients ‎‎was 26.81 (7.23) years. Regarding gender, 57% of the patients were female and 43% ‎‎were male. The highest level of education was masters and bachelors (48%) and most ‎of the patients were students and employees. Overall, 10% of ‎patients had a history of ‎skin disease (eczema/hives/fungal infection) and 7% of patients had taken antibiotics ‎in the previous two months. In addition, 3% of ‎patients had an underlying disease ‎‎(blood pressure/CVA/diabetes). The most ‎common skin manifestations were acne ‎‎(85%), rosacea (11%) and blepharitis (4%). ‎On examination, Demodex was positive in 6 ‎cases (6%), with 4 cases of mild and 2 ‎cases of moderate involvement. This study ‎investigated the frequency distribution of ‎Demodex infection in patients according to ‎sex, age, education level, skin ‎manifestations, history of skin disease, underlying ‎disease, history of ‎antibiotic use, marital status, and occupation. Among these, only ‎the relationship ‎between Demodex infection and history of skin disease was ‎statistically significant, ‎such that half of the infected patients had a history of skin ‎disease.‎
  • Conclusion: The current study showed that compared with other studies, the prevalence of D. ‎folliculorum infection is much lower and is about 6% in patients with suspicious ‎‎symptoms, and on the other hand, according to the current study, infection with this ‎parasite is ‎only related to the positive history of skin disease and no significant ‎relationship with other ‎variables was observed.‎
  • Keywords: Demodex folliculorum, Infection, Skin lesions.