Associations between Demodex species infestation and various types of cancer

Abstract

Tumor-associated immune system cells secrete protease and cytokines that can inhibit the immune response. In particular, T-cell effector functions could be inhibited, potentially causing an increase in parasitic infestations. Demodex species are common inhabitants of normal hair follicles. Humans are the specific host for two species Demodex folliculorum and D. brevis. The aim of this study was to investigate the incidence and infestation of D. folliculorum and D. brevis in patients with cancer. In the present study, 101 patients with cancer were selected from among patients who were diagnosed and treated for cancer. The cancer patients were divided into four groups according to cancer type. Slides were examined for parasites using light microscopy at magnifications of ×40 and ×100. Infestation was defined as having at least five living parasites/cm 2 of skin. The ages of the patients with cancer ranged between 38 and 82 years, with a mean of 65.5±10.1 years. It was determined that 77 of the 101 (76.2%) cancer patients were positive for Demodex species. Infestation was positive in 18 (47.4%) of the 38 cases in the breast cancer group, 7 (29.2%) of the 24 cases in the lung cancer group, 5 (18.5%) of the 27 cases in the gastrointestinal system cancer group, and 2 (16.7%) of the 12 cases in the urogenital system cancer group. Results showed that the rate of Demodex species infestation was higher in patients with breast cancer. Thus, cancer -and particularly breast cancer -is a risk factor for Demodex species infestation.

The effect of skin moisture,pH, and temperature on the density ofDemodex folliculorumandDemodex brevis(Acari: Demodicidae) in students and staff of the Erzincan University, Turkey

“…In the majority of studies, the infestation rate was higher in older as compared to younger individuals . This was also the case in our study, where the older staff members were significantly more infested than the younger students, while a borderline statistical difference was found among the different age groups, where older participants had a higher prevalence than the younger ones.…”

“…In the present study, more men were infested with Demodex mites than women, though the differences were not significant. While some studies also showed that Demodex prevalence is higher in men than women, in other studies the prevalence was higher in women or equal among men and women …”

An intensely pruritic eruption following hematopoietic cell transplant

“…In the post‐transplant setting, Demodex folliculitis has been reported to mimic GVHD . Other important causes of erythematous or papulopustular rashes in post‐HCT patients include drug eruptions, viral exanthems, steroid‐induced acne, photosensitivity, and phototoxic drug reactions .…”

“…In the post-transplant setting, Demodex folliculitis has been reported to mimic GVHD. 2 Other important causes of erythematous or papulopustular rashes in post-HCT patients include drug eruptions, viral exanthems, steroid-induced acne, photosensitivity, and phototoxic drug reactions. 1 Confirming the diagnosis can be challenging as the mite is part of the normal flora and is not always visualized on skin biopsy, as occurred in this case, leading to a delay in diagnosis.…”

Demodex folliculorum Infestation in a Patient with Hodgkin's Lymphoma: A Case Report

“…Ayrıca bazı kanser türlerinde Demodex sp. ile enfestasyon insidansının artabileceğini bildiren çalışmalar mevcuttur (4,5) . Sunduğumuz olgu ile kanser, kemoterapi tedavisi, kronik böbrek yetmezliği, organ transplantasyonu gibi immun sistemi bozan durumların Demodex sp.…”