Demodex-associated folliculitis

Identification of cutaneous fungi and mites in adult atopic dermatitis: analysis by targeted 18S rRNA amplicon sequencing

BACKGROUND

Atopic dermatitis (AD) patients have an altered skin bacterial community, with an abundance of Staphylococcus aureus associated with flares, highlighting that microbial organisms may be important for disease exacerbation. Despite strong evidence of association between bacterial skin colonisation and AD, very limited knowledge regarding the eukaryotic microbial community, including fungi and ectoparasites, in AD exists. In this study, we compared the skin and nasal eukaryotic microbial community between adult AD patients (n = 55) and non-AD healthy controls (n = 45) using targeted 18S rRNA amplicon sequencing. Analysis was based on the presence or absence of eukaryotic microorganisms.

RESULTS

The cutaneous composition of the eukaryotic microbial community and the alpha-diversity differed significantly between AD patients and non-AD individuals, with increased species richness on AD skin. Alpha-diversity and beta-diversity were similar on lesional and non-lesional skin of patients. The ectoparasite Demodex folliculorum and the yeast Geotrichum candidum were significantly more prevalent on the skin of AD patients. The prevalence of D. folliculorum on lesional skin was greater among patients recently treated with topical corticosteroid. Malassezia was one of the most frequently detected genera at all sites, with M. globosa and M. restricta being the most prevalent. M. restricta was under represented in the anterior nares of AD patients as compared to the non-AD control population.

CONCLUSION

Significant differences in the eukaryotic microbial communities were found between AD patients and non-AD individuals, with the most striking finding being the significantly overrepresentation of D. folliculorum on AD skin. Whether D. folliculorum can contribute to skin inflammation in AD needs further investigation.

Role of Adenosine Deaminase in Patients with Erythematotelangiectatic Rosacea and Demodex folliculorum Positivity

Background

Adenosine deaminase (ADA) is an aminohydrolase involved in the catabolism of purine nucleotides and irreversibly deaminizes adenosine and deoxyadenosine to inosine and deoxyinosine. ADA enzyme deficiency results in the loss of functional properties of B and T lymphocytes. Demodex species have been reported to be transmitted between humans through close contact and to play a role in the pathogenesis of rosacea, acne vulgaris, perioral dermatitis, seborrhoeic dermatitis, micropapillary-pruritic dermatitis and blepharitis. The present study aimed to compare serum ADA levels in D. folliculorum positive patients with the healthy control individuals.

Methods

Serum ADA levels were examined for 30 patients diagnosed with erythematotelangiectatic rosacea and 40 healthy individuals in Malatya Inonu University in 2017. Standardized skin surface biopsy (SSSB) method was used to diagnose D. folliculorum. A significant decrease was found in the ADA levels of Demodex-positive rosacea patients when compared to the control group.

Results

ADA levels were decreased in the Demodex-positive group. The mean ADA level in patient group was significantly lower than the mean in the control group (P<0.001). There was no significant difference between the patient and control groups in terms of age and gender.

Conclusion

During and after treatment of Demodex-positive rosacea patients, determination of ADA levels may give more detailed information on the immune mechanisms.

Quantitative Analysis of the Bacteria in Blepharitis With Demodex Infestation

Bacterial infection or Demodex infestation has been reported to contribute to chronic blepharitis. The association between Demodex mites and bacterial flora in this disease remains to be elucidated. Fifty-six consecutive patients diagnosed with chronic blepharitis and 46 healthy volunteers were recruited for this study. Using specimens of three epilated eyelashes and lid margin swabs, Demodex were identified microscopically and bacteria were determined by cultures, followed by colony counting and mass spectrometry. We found 191 Demodex mites, 161 D. folliculorum and 30 D. brevis, in 45 patients. Correspondingly, 101 Demodex, 63 D. folliculorum and 38 D. brevis, were found in 21 controls (p < 0.05, both). Bacterial culture-positivity was obtained in samples (eyelashes, lid margins, or both) from 54 patients and in eyelashes from 37 controls. The total colony counts and the incidences and colony counts of Propinibacterium acnes and Staphylococcus aureus from patients’ eyelashes were significantly higher than that of the controls. Furthermore, bacterial colony counts in blepharitis patients’ eyelashes with D. folliculorum were higher than that of controls with D. folliculorum (p < 0.01). Similarly, P. acnes colonies increased significantly in patients’ eyelashes with D. folliculorum (p < 0.05). These results suggest that D. folliculorum and P. acnes have a role in the occurrence of the chronic blepharitis. Further studies are required to reveal the relationship between these two organisms in blepharitis.

Assessment of demodex presence in acne-like rash associated with cetuximab

CONTEXT

Cetuximab is an epidermal growth factor receptor inhibitor. It is frequently used in the treatment of solid tumors. However, it has a high potential to cause acne-like rash. Demodex mites, which are known to increase in number in immunosuppressive circumstances, are closely related to the acneiform lesions.

OBJECTIVE

The aim of this study is to evaluate the presence of demodex mites in acne-like rash that appears under the treatment of Cetuximab.

METHODS

We reviewed the medical records of patients who applied to our clinic with cetuximab induced papulopustular rashes between November 2014 and March 2016. Demodex sampling was performed by standardized skin surface biopsy (SSSB) in a total of 11 patients (eight males and three females). Infestation was defined as at least 5 living parasites/cm² of skin.

RESULTS

Upon the SSSB examination in 10 out of the 11 patients, no demodex mites were detected. Demodex mites were found in only one of the patients. This patient, in whom two dead Demodex folliculorums were found through facial sampling, was also regarded as negative since his demodex density was under the threshold limit value.

CONCLUSION

In this study, it has been concluded that acne-like rash that develops under the treatment of cetuximab is not related to the presence of demodex mites. Papulopustular eruptions that develop under cetuximab treatment should not be directly correlated with the presence of demodex; first SSSB and demodex presence should be evaluated.

Neutrophilic sebaceous adenitis with intralobular Demodex mites: a case report and review of the literature

A 61-year-old white man presented with a 1-week history of an asymptomatic erythematous, annular plaque with minimal scale limited to the nasal bridge. Histological examination showed a mixed infiltrate of lymphocytes and neutrophils within sebaceous glands. The clinical and histopathological presentation was consistent with a diagnosis of neutrophilic sebaceous adenitis. Several Demodex brevis mites were present deep within the affected sebaceous lobules. Demodex brevis mites are uncommon inhabitants of sebaceous glands of the nose, presenting more commonly on other body sites. The cause of neutrophilic sebaceous adenitis is unknown, but the presence of D. brevis in affected sebaceous glands in this case suggests a possible association.

The Clinical Importance ofDemodex folliculorumPresenting with Nonspecific Facial Signs and Symptoms

Demodex folliculorum (D. folliculorum), found in the pilosebaceous unit, is the most common ectoparasite of humans. Various clinical forms such as pustular folliculitis, papulopustular scalp eruptions, perioral dermatitis, and blepharitis have been defined, although in general, the disease has been classified into three main groups as "pityriasis folliculitis", "rosacea-like demodicidosis", and granulomatous rosacea-like "demodicidosis gravis". Our aim was to test for the presence of D. folliculorum in pathogenic numbers in patients who came to our clinic with non-specific symptoms such as facial itching with or without erythema, seborrheic dermatitis-like or perioral dermatitis-like lesions, papulopustular lesions, and an acneiform clinical appearance without telengiectasia or flushing. Twenty-eight (87.5%) female and 4 male (12.5%), patients and 33 age-and-sex matched healthy subjects enrolled in this study. D. folliculorum was sought in the lesion sites using the non-invasive method known as the Standardised Skin Surface Biopsy (SSSB). The discovery of more than five parasites in an area of 1 cm2, was evaluated as pathogenic. For treatment, 5% permethrine cream was applied twice daily for 15 to 30 days. The clinical symptoms of the patients were classified into clinical groups and evaluated as facial itching in 2 (6.3%), nonspecific erythema and itching in 21 (65.6%), erythema and pityriasiform squamous lesions in 3 (9.4%), acneiform in 3 (9.4%), papulopustular lesions in 1 (3.1%), granulomatous rosacea-like in 1 (3.1%), and perioral dermatitis-like symptoms in 1 (3.3%), D. folliculorum density was determined as 5>D/cm2 in all clinical lesions. A significant clinical healing and density of D. folliculorum at <=5 D/cm2 was determined in all but two patients after treatment. We consider that D. folliculorum presentation with different symptoms and signs than classical forms is not rare. For this reason, we suggest that it is useful to test for D. folliculorum in patients with non-classical presentations like facial itching, itching accompanied by non-specific erythema, itching and non-specific pityriasiform squamous lesions, and acneiform lesions.

Human demodex mite: the versatile mite of dermatological importance

Demodex mite is an obligate human ecto-parasite found in or near the pilo-sebaceous units. Demodex folliculorum and Demodex brevis are two species typically found on humans. Demodex infestation usually remains asymptomatic and may have a pathogenic role only when present in high densities and also because of immune imbalance. All cutaneous diseases caused by Demodex mites are clubbed under the term demodicosis or demodicidosis, which can be an etiological factor of or resemble a variety of dermatoses. Therefore, a high index of clinical suspicion about the etiological role of Demodex in various dermatoses can help in early diagnosis and appropriate, timely, and cost effective management.

Preparation and evaluation of a multimodal minoxidil microemulsion versus minoxidil alone in the treatment of androgenic alopecia of mixed etiology: a pilot study

Background:

The variable success of topical minoxidil in the treatment of androgenic alopecia has led to the hypothesis that other pathways could mediate this form of hair loss, including infection and/or microinflammation of the hair follicles. In this study, we prepared a multimodal microemulsion comprising minoxidil (a dihydrotestosterone antagonist), diclofenac (a nonsteroidal anti-inflammatory agent), and tea tree oil (an anti-infective agent). We investigated the stability and physicochemical properties of this formulation, and its therapeutic efficacy compared with a formulation containing minoxidil alone in the treatment of androgenic alopecia.

Methods:

We developed a multimodal oil/water (o/w) microemulsion, a formulation containing minoxidil alone, and another containing vehicle. A three-phase diagram was constructed to obtain the optimal concentrations of the selected oil, surfactant, and cosurfactant. Thirty-two men aged 18–30 years were randomized to apply 1 mL of microemulsion containing the multimodal formulation (formulation A, n = 11), minoxidil alone (formulation B, n = 11) or placebo (formulation C, n = 10) twice daily to the affected area for 32 weeks. Efficacy was evaluated by mean hair count, thickness, and weight on the targeted area of the scalp. Global photographs were taken, changes in the area of scalp coverage were assessed by patients and external investigators, and the benefits and safety of the study medications were evaluated. The physical stability of formula A was examined after a shelf storage period of 24 months.

Results:

Formulation A achieved a significantly superior response than formulations B and C in terms of mean hair count (P < 0.001), mean hair weight (P < 0.001), and mean hair thickness (P < 0.05). A patient self-assessment questionnaire demonstrated that the multimodal minoxidil formulation significantly (P < 0.001) slowed hair loss, increased hair growth, and improved appearance, and showed no appreciable side effects, such as itching and/or inflammation of the scalp compared with the minoxidil alone and placebo formulations. These improvements were in agreement with the photographic assessments made by the investigators. Formula A was shown to be an o/w formulation with consistent pH, viscosity, specific gravity, and homogeneity, and was physically stable after 24 months of normal storage.

Conclusion:

A multimodal microemulsion comprising minoxidil, diclofenac, and tea tree oil was significantly superior to minoxidil alone and placebo in terms of stability, safety, and efficacy, and achieved an earlier response in the treatment of androgenic alopecia compared with minoxidil alone in this 32-week pilot study.

Potential role of Demodex mites and bacteria in the induction of rosacea

Rosacea is a common dermatological condition that predominantly affects the central regions of the face. Rosacea affects up to 3 % of the world's population and a number of subtypes are recognized. Rosacea can be treated with a variety of antibiotics (e.g. tetracycline or metronidazole) yet no role for bacteria or microbes in its aetiology has been conclusively established. The density of Demodex mites in the skin of rosacea patients is higher than in controls, suggesting a possible role for these mites in the induction of this condition. In addition, Bacillus oleronius, known to be sensitive to the antibiotics used to treat rosacea, has been isolated from a Demodex mite from a patient with papulopustular rosacea and a potential role for this bacterium in the induction of rosacea has been proposed. Staphylococcus epidermidis has been isolated predominantly from the pustules of rosacea patients but not from unaffected skin and may be transported around the face by Demodex mites. These findings raise the possibility that rosacea is fundamentally a bacterial disease resulting from the over-proliferation of Demodex mites living in skin damaged as a result of adverse weathering, age or the production of sebum with an altered fatty acid content. This review surveys the literature relating to the role of Demodex mites and their associated bacteria in the induction and persistence of rosacea and highlights possible therapeutic options.

Cytologic findings inDemodex folliculitis: A case report and review of the literature

Infectious folliculitis of the head and neck has various etiologies, including bacteria, viruses, fungi, and parasites. Accurate morphologic recognition of microorganisms in biopsy and cytologic specimens is paramount in facilitating appropriate therapy. We report a case of a 37-yr-old white male with Demodex folliculitis, who presented with an extensive and painful erythematous pustular skin lesion along the right face and scalp in a dermatome pattern clinically suggestive of Varicella zoster. Examination of scraped smears obtained from one of these pustules revealed numerous parasitic organisms having morphologic features typical of Demodex. Herein, we describe the patient's clinical presentation, discuss the cytologic findings of scrape smears, and briefly review the literature.

Immune response in demodicosis

BACKGROUND

Demodex folliculorum and Demodex brevis are obligatory parasites in the hair follicles and in the pilosebaceous glands. Although most people are infested with these mites, only a small number develop the clinical symptoms of demodicosis. The objective of this study was to determine the distinguishing features of the immune response to the infestation of the skin by Demodex mites.

METHODS

Twenty-nine patients with human demodicosis and 13 age- and sex-matched healthy subjects participated in the study. The presence of mites was determined by microscopic inspection of secretion from sebum glands. The immune response was evaluated in the peripheral blood by identifying membrane markers of different immune cells using monoclonal antibodies, while the concentration of immunoglobulin (Ig)A, IgM and IgG was calculated by simple radial immunodiffusion using anti-IgA, anti-IgM and anti-IgG. The level of circulating immune complexes and total haemolytic complement, as well as the preparatory and digestive function of neutrophils, and the functional activity of leucocytes were also studied.

RESULTS

The absolute number of CD95+ was higher in patients with demodicosis. The absolute number of CD3+, CD4+, CD8+ and CD16+ cells, the ratio CD3+/CD20+ and the functional activity of leucocytes were significantly lower in individuals infested with Demodex mites. No significant differences were found in the percentage and absolute number of CD20+ cells, the ratio of CD4+/CD8+ T-cell subpopulations, circulating immune complexes, level of serum complement activity (CH(50)), activity and index of phagocytosis and the levels of IgA, IgM and IgG antibodies between individuals infested with Demodex mites and the control group.

CONCLUSION

The readiness of lymphocytes to undergo apoptosis increases in parallel to the increasing density of the mites. This could be the result of local immunosuppression caused by the mites, which allows them to survive in the host skin.

High incidence of demodicidosis in eyelid basal cell carcinomas

BACKGROUND

Although UV radiation is the major cause of basal cell carcinoma (BCC), local factors, such as chronic trauma, irritation, or inflammation, may also have some role in its etiopathogenesis. The pilosebaceous follicle mites, Demodex folliculorum and D. brevis, inhabit most commonly and densely certain facial skin areas, including the nose and periorbital regions, where BCC also develops most frequently.

AIM

To investigate, in a retrospective histopathologic study, whether a possible etiopathogenetic relationship exists between demodicidosis and eyelid BCCs.

METHODS

We examined 32 eyelid BCC specimens that contained at least five eyelashes or five hair follicles with respect to the presence and density of Demodex mites. As controls, we evaluated 34 matched specimens consisting of benign eyelid skin lesions.

RESULTS

Twenty-one of 32 BCC cases (65.6%) and eight of 34 control cases (23.33%) had demodicidosis. Mean mite counts were 1.31 +/- 1.57 and 0.47 +/- 0.99 in BCC cases and controls, respectively. The differences were significant for both prevalence (P < 0.001) and density (P = 0.0052). Although there was a significant positive correlation between increasing mite number and patient age in the control group (r = 0.47, P < 0.05), no significant correlation was found between these two factors in BCC cases (r = -0.102, P > 0.05).

CONCLUSIONS

Demodicidosis may be one of the triggering factors of carcinogenesis in eyelid BCCs in otherwise predisposed people due to its traumatic/irritating effect or chronic inflammation.

Effects of intense pulsed light on sun-damaged human skin, routine, and ultrastructural analysis

BACKGROUND AND OBJECTIVE

New, non-ablative methods can be used in skin rejuvenation. Histologic analysis of non-ablative IPL effects on facial, sun-damaged skin.

STUDY DESIGN/MATERIALS AND METHODS

Five female subjects, wrinkle class I or II and Fitzpatrick skin types I, II, and III. IPL treatment: once monthly, 560-nm cut-off filters, spot size 8x35 mm, 28-36 J/cm. Routine histology or electron microscopy on 2-mm punches, before treatment and then 1 week, 3 months, and 12 months.

RESULTS

Pre-treatment specimens contained solar elastosis and perifollicular lymphoid infiltrates. Collagen and elastic fibers appeared unaffected by treatment. At 1-week, Demodex organisms appeared coagulated.

CONCLUSIONS

Under these conditions, IPL induces minimal morphologic changes in mildly sun-damaged skin. Some esthetic improvement may be secondary to clearing of Demodex organisms and reduction of associated lymphocytic infiltrate.