Prevalence and density of Demodex mites (Acari: Demodecidae) in patients with seborrheic dermatitis

Abstract

This study was conducted to determine the prevalence and density of Demodex mites in patients with seborrheic dermatitis. The study included 37 patients and 35 healthy controls who were diagnosed with seborrheic dermatitis by clinical examination. The sample materials were taken from the cheek, nasolabial and jaw areas of the participants using the standard superficial skin biopsy method and examined for the presence and number of Demodex mites under light microscopy. Demodex spp. mites were detected in 34 (91.9%) of the patients and in 20 (60%) of the controls. Demodex folliculorum was detected in 34 of 37 patients (mean 15.7/cm2; total 535) and D. brevis (mean 0.6/cm2; 20 total) in six patients. Demodex folliculorum was detected in 20 of 35 healthy controls (mean 2.7/cm2; total 56) and D. brevis (mean 0.5/cm2; total 1) in one of the 35 healthy controls. When patients and controls were compared in terms of Demodex prevalence and density, the differences were statistically significant. In conclusion, Demodex mites are more prevalent in patients with seborrheic dermatitis in Erzincan Province of Turkey. This condition may be related to the amount of sebum in patients with seborrheic dermatitis, however, this issue should be supported by further studies in which sebum levels are measured and ilarger number of patients are involved.