Arch Dermatol Res. 2009 Aug 4; Borgo SN, Sattler EC, Hogardt M, Adler K, Plewig GIn many skin diseases such as Demodex folliculitis, rosacea- or steroid-induced rosacea Demodex mites are present in abundance and are at least partially held responsible for causing these disorders. Although it is known that these diseases respond well to tetracyclines, it is unclear if this is due to the antiinflammatory effects of the antibiotics or to an antibacterial effect on so far unknown bacteria within the Demodex mites. As in filariasis, where the response to doxycycline can be explained by the presence of Wolbachia within the filarial nematodes, this study was performed to see whether Wolbachia also use Demodex mites as their hosts. Human and canine Demodex mite samples were taken by skin scrapings and tested by PCR for the presence of Wolbachia DNA. Wolbachia pipientis DNA was used as positive control. In none of the DNA extracts, Wolbachia were detected showing no evidence for the presence of these bacteria in Demodex mites. The response of Demodex aggravated or Demodex caused diseases to tetracyclines seems not to be due to the presence of Wolbachia in Demodex mites in contrast to the results seen in filariasis.
To estimate the prevalence of dry eye and to investigate its relationship with lifestyle and systemic factors in a general adult population in north-western Spain. METHODS: A dry eye questionnaire was administered and objective tests were performed in 654 individuals [mean age (Standard deviation): 63.6 (14.4) years, range: 40-96, 37.2% males]. Subjects were considered symptomatic when one or more of the symptoms of the questionnaire were present often or all the time. Schirmer test or= 3 and fluorescein staining >or= 1 were considered indicative of signs. Dry eye was defined as the simultaneous presence of symptoms and at least one sign. A design based analysis was performed and all calculations were weighted to give unbiased estimates. RESULTS: Dry eye prevalence was 11.0% (95%confidence interval [CI] 8.6-13.3). Dry eye was found to be more frequent in women (11.9%, 95%CI 8.8-15.1) than in men (9.0%, 95%CI 5.3-12.6), and was significantly associated with aging (p autoimmune diseas...