title: The effects of sebum configuration on Demodex spp. density.
abstract: OBJECTIVE
  Demodex spp. are ectoparasites living in the pilosebaceous units, which feed on the host's sebum and cellular proteins. The protective barrier of the skin consists of sebum secretion, moisture, and the acid mantle. In this study, we aimed to determine the effects of skin sebum, moisture, pH levels, and sebum configuration on Demodex spp. density.
  
  
  METHODS
  Forty-five patients who had demodicosis were enrolled in the study group, while the control group consisted of 40 subjects without demodicosis. Body fat percentage, serum triglyceride and cholesterol levels, skin sebum, moisture, and pH levels were measured. Demodex spp. density was determined with a standardized skin surface biopsy. Sebum samples were taken from the forehead and a high-performance thin-layer chromatography (HPTLC) method was performed on these samples. Subsequently, densitometric analyses were applied to the HPTLC plates.
  
  
  RESULTS
  Demodex spp. were found on the cheeks and lived in an alkali environment. Skin sebum and moisture levels were low in all groups. The skin pH levels and cholesterol ester in the sebum configuration were determined to be significantly higher in the group with demodicosis.
  
  
  CONCLUSIONS
  We suggest that Demodex spp. may use cholesterol ester in the sebum as nutriment. In other words, cholesterol ester may be a suitable growth medium for the proliferation of Demodex spp.
authors.affiliation: Department of Dermatology, Ankara Oncology Training and Research Hospital, Ankara, Turkey.
authors.forename: Hatice Gamze
authors.initials: HG
authors.lastname: Demirdağ
authors.affiliation: Department of Dermatology, Faculty of Medicine, İnönü University, Malatya, Turkey.
authors.forename: Hamdi
authors.initials: H
authors.lastname: Özcan
authors.affiliation: Department of Biochemistry, Faculty of Medicine, İnönü University, Malatya, Turkey.
authors.forename: Şule
authors.initials: Ş
authors.lastname: Gürsoy
authors.affiliation: Department of Organic Agriculture, Tunceli Vocational School, Tunceli University, Tunceli, Turkey.
authors.forename: Gülçin
authors.initials: G
authors.lastname: Beker Akbulut
mesh_terms: D000818:Animals; D001706:Biopsy; D006801:Humans; D008925:Mites; D012629:Sebum; D012867:Skin
keywords: Demodex spp.; sebum configuration; skin sebum