The Association between Demodex Infestation and Hair Loss Severity in a Referred Patient Population

Hair follicle mites of the genus Demodex (Prostigmata: Demodicidae) are the most common external obligate parasites in humans, which reside in the eyelids, sebaceous glands, and ear canal, and can cause clinical disease. The purpose of this study was to investigate the possible role of Demodex parasites in causing discomfort in patients referred to Tehran laboratories due to hair loss.

This cross-sectional study was conducted on 520 patients referred to a laboratory in Tehran, Iran, presenting with hair loss. Sampling was performed from the scalp and face, and samples were examined for Demodex mites using light microscopy.

The results showed that among the 520 patients referred to the laboratory, 66.15% were infected with Demodex. Out of 344 positive cases, 83.43% were women and 16.57% were men. Among the affected patients aged between 7 and 70 years, most patients (59.01%) were in the age group of 25.4 to 39.2 years. A high prevalence of Demodex infestation (66.15%) was found among patients with hair loss.

Our findings establish a highly significant, direct correlation between the severity of hair loss and the density of Demodex mite infestation (p< 0.001). We propose that high Demodex mite density is a significant contributory factor in the etiology of severe hair loss.