New modified diagnosis method for detection Demodex mites in affected people with demodicosis

BACKGROUND AND OBJECTIVESDemodex mites are the most common human ectoparasites. Demodex species can be found on all skin types across a broad geographical range. Demodex mites reside in the pilosebaceous units of the skin. Demodex mites feed on epithelial and glandular cells as well as sebum typically secreted by active pilosebaceous units. Demodicosis is the infestation of Demodex mites on the face, whereby a minimum of ۵ mites/cm۲ exist and induce symptoms such as redness of the skin (erythema), telangiectasia, itching, heat, scaling, papules, pustules, and dermatitis, usually accompanied by a burning or pruritic sensation. Bacterial folliculitis, rosacea, seborrheic dermatitis and other common skin conditions have been linked to infestation by Demodex mites (human demodicosis). The diagnosis of demodicidosis should be established by the visualization of Demodex mites in high numbers.MATERIALS AND METHODSWe used new method for observation Demodex mites precisely. Considering the diameter of the head of sampling tool is ۲ mm, in order to sample an area of ۱ square centimeter of the skin, it is necessary to sample the sebum of ۵ areas of facial skin with a length of ۱۰ mm. These five areas include ۱۰ mm areas from the top of both eyebrows, ۱۰ mm areas from the right and left side of the nose, and a ۱۰ mm area from the border line of the forehead and five areas of different place on scalp. Finally, we have collected a diameter of ۱ square centimeter or ۱۰۰ square millimeters. After transfer of sebum samples to drop of oil on a laboratory slides, a drop for facial skin and scalp, separately; Then we put a cover slide on each drop. The preparation was examined under a light microscope (Olympus SZX۱۶ microscope) ۴۰× and ۱۰۰× magnification. Multiple sections (about ۵ on average) on every slide were examined. All forms of Demodex follicularom and Demodex brevis mites: adult, larvae and egg forms were counted as results. (A positive level of ≥۵/cm۲ area was considered as a criterion for demodex positivity in patients).RESULTS AND DISCUSSIONIn this study we have modified Current diagnostic method and improve the defects of previous methods such as skin surface biopsy (SSB), Dermoscopy and etc . This new modified method has the advantage of being noninvasive, inexpensive, accurate and rapid.CONCLUSIONWe investigated a new sampling method for determining the presence mites and the severity of Demodex infestation, in both the patient and control groups. Methods commonly used to determine demodex mite densities have many defects such as being time consuming and require specific equipment and a trained observer. The results of our study revealed that our new method based on direct microscopic identification of Demodex mites is a more sensitive method for detecting Demodex mite than SSSB and Dermoscopy. Our sampling method used was not invasive and results are more precise, fast and inexpensive.

کلیدواژه ها:

Demodex mite ، Diagnosis method ، Demodicosis ، Microscopic identification