Research on the relationship between Demodex mites densityand redness and inflammatory dermatoses

Background and Aim : Demodex are highly specialized mites that are normal inhabitants of hairfollicles and sebaceous glands of the skin. While Demodex mites are part of the normal skinmicrofauna, overpopulation in man can be associated with significant disease. Finding largequantities of Demodex may play an important role in the pathogenesis of undefined and evendefined inflammatory dermatoses and redness of the skin. Then, we aimed to evaluate demodexdensity in patients with redness and inflammatory skin condition.Methods : Direct microscopic examination was done noninvasively from ۱ cm۲ of facial skin andsebum of the skin after collected was analysed for presence of demodex mites density. The patientgroup consisted of ۱۰۰ individuals who were admitted Dermatology Clinic and were diagnosedwith skin problems. The age range was ۱۶–۵۵ years. The control group consisted of ۱۰۰ age-, sex-, and skin phenotype-matched healthy volunteers.Results : A density of more than ۵ mites/cm۲ specimen has been considered to be pathogenic.Demodex mite sampling was positive in patients (۷۳%) compared with controls (۱۲%). Theaverage of Demodex mite density in patinets with redness and inflammated skin was ۴۲.۶۶count/cm۲ and ۲.۷۳ count/cm۲ in facial and scalp area, respectively. Demodex mite test waspositive in ۱۲ men (۱۷%) and ۶۱ women (۸۳%) in case groups. Research has shown Demodexmite density is higher in patients with the inflammated and redness skin condition, and treatmentwith acaricidal agents is effective in resolving symptoms.Conclusion : The host’s immune system seems to tolerate Demodex without inflammation as acommensal when their numbers are low. However, it appears they participate in inflammationwhen their number increases. These inflammatory conditions may be caused primarily byinfestation with Demodex mites or may be a byproduct of an eruption of colonization due to animmunocompromised state. increased number of mites is considered to cause an increase in theantigenic load, which in turn bypasses the follicles and induces an inflammatory response inneutrophils. Thus, It is important to consider Demodex mites in the etiology of unexplained orsevere cases of skin diseases.

کلیدواژه ها:

Demodex mites ، Inflammation ، Redness ، Dermatoses