Purpose: The aim of the study was the evaluation of the role of Demodex infestation in acne/rosacea, folliculitis, perioral dermatitis. Patients and Method: One hundred and forty-eight outpatients were enrolled and the direct microscopic examination of the lesions was done. Results: 83% of patients were women. The mean age was 31.21 years (SD=14.2). 84% of patients had positive results for Demodex folliculorum. The presence of pets could be a risk for infestation, but 33% of patients had no contact with animals. Oral metronidazole for 10 days and a month of topical benzyl benzoate mixture (6.5%-12.5%) added with a metronidazole mixture had significant favorable effects. The treatment was repeated for another month. Negative microscopic exams were obtained after two months. There was a low risk of recurrence or re-infection. Conclusion: Demodex folliculorum infestation has to be considered in resistant acne/folliculitis, in lower face and cervical acne lesions or in rosacea. It is important to clean the parasitic infection for a better effect of classical therapy of acne.
