Demodicidosis in immunocompetent young children: report of eight cases.

Demodex folliculorum and Demodex brevis are obligate parasites of the human pilosebaceous unit. They are the most common permanent ectoparasites in adults, but their incidence on children's skin is rare. Only few cases of demodicidosis have been reported in children aged below 5 years and most of them were suffering from leukemia or HIV infection. The aim of this study is to describe demodicidosis in young immunocompetent children. The clinical details of 8 healthy children are given. There were 4 males and 4 females aged between 10 months and 5 years referred to us for evaluation of a facial eruption characterized by erythema, papulopustules and variable edema. In 7 of these patients, skin scrapings were performed and in 1 a 4-mm punch biopsy. Numerous D. folliculorum were found in skin scrapings of 7 cases and at a histologic examination of skin biopsy in 1 case. We employed topical metronidazole gel 1% in all patients and we obtained a 100% recovery without relapses after a 1- to 3-year follow-up. In 2 of our cases Demodex infestation had a mild form resembling pityriasis folliculorum and the other cases presented a rosacea-like form. The reason why these young immunocompetent children developed demodicidosis is still under evaluation and investigation.