Reflectance confocal microscopy vs. standardized skin surface biopsy for measuring the density of Demodex mites

Confocal microscopy and optical coherence tomography of inflammatory skin diseases in hairs and pilosebaceous units: A systematic review

Common skin disorders such as acne vulgaris, rosacea and folliculitis are bothersome prevalent inflammatory diseases of hair follicles that can easily be investigated bedside using optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) with micrometre resolution, opening a novel era for high-resolution hair follicle diagnostics and quantitative treatment evaluation. EMBASE, PubMed and Web of Science were searched until 5 January 2023 to identify all studies imaging hair follicle characteristics by RCM and OCT for diagnosis and monitoring of treatment in hair follicle-based skin disorders. This study followed PRISMA guidelines. After inclusion of articles, methodological quality was assessed using the QUADAS-2 critical appraisal checklist. Thirty-nine in vivo studies (33 RCM and 12 OCT studies) were included. The studies focused on acne vulgaris, rosacea, alopecia areata, hidradenitis suppurativa, folliculitis, folliculitis decalvans, lichen planopilaris, discoid lupus erythemasus, frontal fibrosing alopecia and keratosis pilaris. Inter- and perifollicular morphology including number of demodex mites, hyperkeratinization, inflammation and vascular morphology could be assessed by RCM and OCT in all included skin disorders. Methodological study quality was low, and interstudy outcome variability was high. Quality assessment showed high or unclear risk of bias in 36 studies. Both RCM and OCT visualize quantitative features as size, shape, content and abnormalities of hair follicles, and have potential to support clinical diagnosis and evaluate treatment effects. However, larger studies with better methodological quality are needed to implement RCM and OCT directly into clinical practice.

A novel multi-layer perceptron model for assessing the diagnostic value of non-invasive imaging instruments for rosacea

Background

Reflectance confocal microscopy (RCM), VISIA, and dermoscopy have emerged as promising tools for objective diagnosis and assessment of rosacea. However, little is known about the diagnostic value of these imaging systems for rosacea.

Objectives

To assess the diagnostic value of RCM, VISIA, and dermoscopy for rosacea by establishing a novel multilayer perceptron (MLP) model.

Methods

A total of 520 patients with rosacea and other facial diseases were included in this study. A total of 474 samples of dermoscopy data, 374 samples of RCM data, 434 samples of VISIA data, and 291 samples containing three data sources were collected. An MLP model was built with the total data to explore the association between the imageological features of each instrument and the probability of rosacea.

Results

Our MLP model revealed that the area under the receiver operating characteristic curve (AUROC) values of RCM, VISIA and dermoscopy for diagnosing rosacea were 0.5233, 0.5646 and 0.7971, respectively. The integration of these three tools with clinical data could further improve the accuracy of the predictive diagnosis to 0.8385. For the imageological features of each tool, abnormalities (hyperkeratosis or parakeratosis) in the stratum corneum were effective variables for excluding rosacea (odds ratio [OR], 0.4333) under RCM. The indicators of rosacea under VISIA included overall severity of erythema, erythema involving the cheek or superciliary arch, visible red blood vessels, and papules (OR = 2.2745, 3.1592, 1.8365, 2.8647, and 1.4260, respectively). The candidate variables of dermoscopy included yellow background, white background, uniform distribution of vessels, branched vessels, and reticular blood vessels (OR = 0.4259, 0.4949, 2.2858, 3.7444, and 2.4576, respectively).

Conclusions

RCM, dermoscopy, and VISIA each can present several imageological features and were of certain value for assisting rosacea diagnosis. The combined analysis of these three tools using our MLP model may be useful for improving the accuracy of diagnosing rosacea.

Rapid Office-Based Diagnosis of Demodex Using an Innovative Smartphone-Aided Intraocular Lens Tool

ABSTRACT

Demodex is an important pathogen causing eyelid and eyelash diseases. This article describes a quick, efficient, cost-effective office-based imaging of demodex with the help of an intraocular lens (IOL) and smartphone-aided innovated tool. Eyelid photography of a 56-year-old man with suspected demodex infestation was obtained using a 20-diopter (D) IOL over the smartphone camera called as Anterior Segment Photography using IOL (ASPI). A video or photograph of the epilated eyelash was taken using four 30-D IOLs attached to the smartphone camera to form an optical system called IOLSCOPE, which clearly detected the demodex parasite. The importance of ASPI and IOLSCOPE for the rapid office-based diagnosis of demodex pathogen in peripheral health centers devoid of slitlamp and microscopes has been emphasized here.

Investigation of the Prevalence of Demodex spp. in Dermatological Diseases

OBJECTIVE

An increase in the counts of the Demodex mites that exist in the microbiota of healthy individuals may lead to some dermatological diseases. This study aimed to investigate the prevalence of Demodex spp. among patients diagnosed with acne vulgaris, rosacea, perioral dermatitis, seborrheic dermatitis, eczema, and pityriasis folliculorum and the relationship between the demographic and clinical data of such patients and Demodex.

METHODS

This study included 144 patients (70 with acne vulgaris, 6 with pityriasis folliculorum, 15 with seborrheic dermatitis, 39 with rosacea, 8 with eczema, and 6 with perioral dermatitis) and 73 healthy subjects. We evaluated Demodex positivity using the standard superficial skin biopsy method in all groups. The presence of more than five Demodex mites per square centimeter was considered positive at the diagnosis.

RESULTS

Of the 144 patients included in the study, 107 (74.3%) were female, and 37 (25.7%) were male, while 40 (54.8%) of the 73 healthy subjects were female, and 33 (45.2%) were male. Twenty-one patients (14.5%) and five of the healthy subjects (6.8%) tested positive for Demodex. We found that Demodex positivity rates in the rosacea and acne vulgaris groups were higher than in the control group. However, this level was not statistically significant (p>0.05). We found the highest positivity rate among the patient groups in the pityriasis folliculorum (4/6, 66.7%), rosacea (8/39, 20.5%), and perioral dermatitis (1/6, 16.7%) groups. Lastly, we found no statistically significant relationship between the demographic and clinical characteristics of the groups and Demodex positivity (p>0.05).

CONCLUSION

The present study is the only study that investigated Demodex positivity in six different dermatological diseases. Based on the results, we believe that investigating Demodex spp. positivity in dermatological diseases such as acne vulgaris, rosacea, and pityriasis folliculorum would be beneficial for early diagnosis and treatment.

The Pathogenic Role of Demodex Mites in Rosacea: A Potential Therapeutic Target Already in Erythematotelangiectatic Rosacea?

Rosacea is a common facial dermatosis but its definition and classification are still unclear, especially in terms of its links with demodicosis. Triggers of rosacea (ultraviolet light, heat, spicy foods, alcohol, stress, microbes) are currently considered to induce a cascading innate and then adaptive immune response that gets out of control. Recent histological and biochemical studies support the concept that this inflammatory response is a continuum, already present from the onset of the disease, even when no clinical signs of inflammation are visible. The Demodex mite is beginning to be accepted as one of the triggers of this inflammatory cascade, and its proliferation as a marker of rosacea; moreover, the papulopustules of rosacea can be effectively treated with topical acaricidal agents. Demodex proliferation appears to be a continuum process in rosacea, and may not be clinically visible at the onset of the disease. Molecular studies suggest that Demodex may induce tolerogenic dendritic cells and collaborate with vascular endothelial growth factor (VEGF) to induce T cell exhaustion and favor its own proliferation. These interactions among VEGF, Demodex, and immunity need to be explored further and the nosology of rosacea adapted accordingly. However, treating early rosacea, with only clinically visible vascular symptoms, with an acaricide may decrease early inflammation, limit potential flare-ups following laser treatment, and prevent the ultimate development of the papulopustules of rosacea. The effectiveness of this approach needs to be confirmed by prospective controlled clinical trials with long-term follow-up. Currently, the evidence suggests that patients with only vascular symptoms of rosacea should be carefully examined for the presence of follicular scales as signs of Demodex overgrowth or pityriasis folliculorum so that these patients, at least, can be treated early with an acaricidal cream.

Effectiveness of benzyl benzoate treatment on clinical symptoms and Demodex density over time in patients with rosacea and demodicosis: a real life retrospective follow-up study comparing low- and high-dose regimens

Background: Patients with rosacea and demodicosis have high facial skin Demodex densities (Dds), which decrease with benzyl benzoate (BB) treatment.Objectives: To evaluate the impact of topical BB (+crotamiton) treatment on Dds and clinical symptoms during prolonged follow-up and to compare low (12% once daily) and high (12% twice daily or 20-24% once daily) BB dose regimens.Methods: This retrospective study included 344 patients (103 rosacea, 241 demodicosis) observed for 7.1 ± 0.5 months. Dds were measured on two consecutive standardized skin surface biopsies and symptoms evaluated using investigator global assessment. Compliance was considered good if patients correctly followed treatment instructions.Results: At final follow-up, in the 248 patients with good compliance, Dd had normalized in 217 (88%) and symptoms cleared in 204 (82%). The high dose was associated with better compliance and faster results than the low-dose. The higher the initial Dd, the longer it took to normalize. In the 96 poorly compliant patients, treatment was less effective and slower.Conclusions: These findings indirectly support a key role of the mite in rosacea and suggest that topical treatment with BB (+crotamiton), especially the higher dose, may be a useful alternative treatment for rosacea as well as for demodicosis.[Formula: see text].

Dupilumab for the Treatment of Atopic Dermatitis in an Austrian Cohort-Real-Life Data Shows Rosacea-Like Folliculitis

Dupilumab is the first biological treatment approved for moderate-to-severe atopic dermatitis (AD). Efficacy and safety have been demonstrated in clinical trials, but real-life data is still limited. The objective of this study was to retrospectively evaluate Dupilumab treatment in AD patients in a real-life clinical setting. Effectiveness and safety outcomes were collected at baseline and after 2, 6, 10, 24, 39, and 52 weeks by using clinical scores for disease activity, as well as serological markers. Ninety-four patients from five dermatological hospitals were included. After 24 weeks of treatment, the median Investigator Global Assessment (IGA) and Eczema Area and Severity Index (EASI) showed a significant reduction compared to baseline (3.9 ± 0.7 vs. 1.4 ± 0.8 and 26.5 ± 12.5 vs. 6.4 ± 6.5). Interestingly, we observed rosacea-like folliculitis as an unexpected side effect in 6.4% of patients. Dupilumab proves to be an effective and well-tolerated treatment under real-life conditions. The occurrence of rosacea-like folliculitis warrants further mechanistic investigation.

Value of reflectance confocal microscopy for the monitoring of rosacea during treatment with topical ivermectin

Background: Reflectance confocal microscopy (RCM) enables noninvasive Demodex mite detection in rosacea. Objective scoring of rosacea severity is currently lacking.Objectives: To determine the value of RCM for monitoring Demodex, inflammation and vascular parameters in rosacea during treatment.Methods: In 20 rosacea patients, clinical and RCM examination were performed before, during, and 12 weeks after a 16-week treatment course with topical ivermectin. Using RCM, number of mites and inflammatory cells, epidermal thickness, and vascular density and diameter were measured. RCM features were correlated with clinical assessment.Results: Treatment resulted in clinical reduction of inflammatory lesions. Mites were detected in 80% of patients at baseline, 30% at week 16, and 63% at week 28. The number of mites reduced significantly during treatment, but no changes in inflammatory cells, epidermal thickness or vascular parameters were observed. Correlation between number of inflammatory lesions and mites was low. None of the RCM variables were significant predictors for clinical success.Conclusions: RCM enables anti-inflammatory effect monitoring of topical ivermectin by determining mite presence. Quantifying exact mite number, and inflammatory and vascular characteristics is challenging due to device limitations. In its current form, RCM seems of limited value for noninvasive follow-up of rosacea in clinical practice.

Erythematotelangiectatic rosacea may be associated with a subclinical stage of demodicosis: a case-control study

BACKGROUND

Facial densities of Demodex mites have been observed to be greater in patients with demodicosis and papulopustular rosacea than in healthy control patients. In patients with erythematotelangiectatic rosacea (ETR), this density has been observed to be similar to or greater than that of healthy controls. Erythema and telangiectasia, characteristics of ETR, are often observed among patients with pityriasis folliculorum, a discreet demodicosis, suggesting a possible link between these conditions.

OBJECTIVES

To compare the facial Demodex densities of patients with clinical ETR and patients with healthy skin, demodicosis, rosacea with papulopustules, and other facial dermatoses.

METHODS

In this retrospective study, we recorded Demodex densities measured using two consecutive standardized skin surface biopsies (SSSB1 and SSSB2) in 23 patients with ETR, 20 healthy control patients, 590 patients with demodicosis, 254 with rosacea with papulopustules and 180 with other facial dermatoses.

RESULTS

Patients with ETR had higher Demodex densities (D cm^-2 ) than did the healthy controls (mean ± SEM; SSSB1: 15·7 ± 6·3 vs. 1·8 ± 1·1 D cm^-2 , P = 0·042; SSSB2: 38·0 ± 13·7 vs. 5·1 ± 2·1 D cm^-2 , P = 0·026) and patients with other dermatoses (SSSB1: 0·4 ± 0·1 D cm^-2 , P = 0·004; SSSB2: 1·3 ± 0·3 D cm^-2 , P = 0·004), but lower densities than patients with demodicosis (SSSB1: 82·7 ± 4·2 D cm^-2 , P = 0·008; SSSB2: 172·2 ± 7·7 D cm^-2 , P = 0·001) or rosacea with papulopustules (SSSB1: 86·6 ± 7·3 D cm^-2 , P = 0·027; SSSB2: 197·0 ± 12·1 D cm^-2 , P = 0·002).

CONCLUSIONS

ETR may be associated with nonvisible Demodex proliferation, possibly corresponding to a subclinical stage of demodicosis. Dermatologists should be aware of this potential association and look for subclinical demodicosis in patients with ETR, so that topical acaricidal treatment can be offered if Demodex density is high.

Office-Based Diagnosis of Demodex Using Smartphone

Demodex is an important pathogen in ophthalmology. It is believed to cause a variety of eyelid and eyelash diseases. Currently, light microscopes are being used for imaging demodex. However, microscopes are not available everywhere. Also, it is not cost-effective to perform light microscopy in every case. In this case, we demonstrate a new method: imaging demodex using cell phone. A 90-diopter noncontact double aspheric lens was attached to the posterior camera of the smartphone with clear tape. An eyelash of a patient with blepharitis was removed. A video was taken using smartphone. There was a moving demodex parasite in the root of the eyelash. A clear video image could be taken using the smartphone. A smartphone and a 90-diopter lens are adequate for the imaging and diagnosis of demodex.

The investigation of the relationships of demodex density with inflammatory response and oxidative stress in rosacea

The relationships of demodex density with systemic oxidative stress, inflammatory response, and clinical severity in rosacea are not clear. This study aimed to (a) analyze the levels of systemic oxidative stress, antioxidant capacity, inflammatory parameters, and matrix metalloproteinases (MMPs) in systemic circulation in patients with rosacea, (b) identify the relationship between mite density and both oxidative stress and inflammation, and (c) investigate the role of photoaging and sebum secretion in etiopathogenesis. Forty patients with rosacea and 40 age-, sex-, and skin phenotype-matched healthy volunteers were included in the study. Clinical disease severity of the patients was determined. Sebum levels were measured in both the groups, and photoaging was evaluated. Reflectance confocal microscopy was used to calculate demodex density. Serum total antioxidant capacity (TAC), total oxidant capacity (TOC), myeloperoxidase (MPO), MMP-1, MMP-9, arylesterase (ARES), interleukin-1β (IL-1β), paraoxonase-1 (PON-1), and tumor necrosis factor-α (TNF-α) levels were also analyzed. The patients with rosacea had significantly higher serum TOC and lower TAC levels (p < 0.001). The serum ARES and PON-1 levels were significantly lower (p = 0.045 and p < 0.001, respectively); however, the serum levels of MMP-1, MMP-9, IL-1β and MPO were higher in the patient group. Demodex parameters were higher in the patient group compared to the control group. There was no significant correlation between the number of mites and disease severity. In addition, the number of mites was not correlated with the serum levels of TAC, TOC, OSI, MPO, MMP-1, MMP-9, ARES, PON-1, TNF-α, and IL-1β. However, sebum levels were directly proportional to the number of mites. Photoaging severity was similar between the patients and control subjects. The changing sebaceous microenvironment in rosacea leads to an increase in the number of demodex mites. However, increased demodex density does not alter disease severity, level of oxidative stress, or inflammation. Although none of the patients with rosacea had any underlying systemic disease, patients' systemic oxidative stress and inflammation parameters were found high in systemic circulation. It is assumed that the patients with rosacea are more prone to systemic diseases.

Dermatoscopy and Reflectance Confocal Microscopy Correlations in Nonmelanocytic Disorders

Dermatoscopy and in vivo reflectance confocal microscopy are noninvasive techniques that provide a horizontal approach, with an en face view of the skin structures. Both techniques assist in the clinical diagnosis of a variety of inflammatory and infectious cutaneous disorders. In many cases, they have shown concordance. Their combined use represents, in several instances, a promising option to reach the final diagnosis without the need for invasive procedures.

Demodex mites in acne rosacea: reflectance confocal microscopic study

BACKGROUND/OBJECTIVES

Demodex mite density is emphasised in the aetiopathogenesis of acne rosacea. Reflectance confocal microscopy (RCM) has been shown to be a good method for determining demodex mite density. The objective was to determine demodex mite density using RCM in acne rosacea patients and compare them with controls.

METHODS

In all, 30 papulopustular rosacea (PPR) and 30 erythematotelangiectatic rosacea (ETR) totally 60 acne rosacea patients and 40 controls, were enrolled in the study. The right cheek was selected for imaging and RCM was used for scanning. Ten images of 1000 × 1000 μm (total 10 mm² ) area were scanned from adjacent areas. The numbers of follicles, infested follicles and mites were counted. The mean numbers of mites per follicle and infested follicles were calculated and compared in the patients and control groups.

RESULTS

The mean number of mites was 44.30 ± 23.22 in PPR, 14.57 ± 15.86 in ETR and 3.55 ± 6.48 in the control group (P < 0.001). The mean number of mites per follicle was 1.77 ± 0.90 in PPR, 0.57 ± 0.63 in ETR and 0.13 ± 0.23 in the control group (P < 0.001). The cut-off for the mean number of mites for determining mite infestation was 0.17 and above.

CONCLUSIONS

Demodex mite density was markedly increased in both ETR and PPR patients. It is believed that the presence of demodex mites plays an important role in rosacea aetiopathogenesis. Demodex mite treatment may reduce the severity of the disease and slow its progressive nature.

Modern demodicosis diagnostics methods

An overview of the modern demodicosis diagnostics methods and in-house demodicosis diagnosis with intravital laser scanning confocal microscopy effectiveness studies. The study included 60 patients with acne and rosacea, complicated demodicosis, 60 patients with acne and rosacea and no demodicosis, and 30 healthy volunteers. All the patients underwent skin scraping, eyebrows and/or eyelashes hair removal and confocal laser-scanning microscopy. the advantages of confocal laser-scanning microscopy in vivo in comparison with conventional methods of research are shown.

Diagnostic value of the confocal laser scanning microscopy in vivo

The confocal laser scanning microscopy in vivo is a promising study method to visualize cell structures of epidermis and papillary dermis without affecting the skin integrity, which provides for a resolution and contrast similar to those characteristic of the classical histology examination. Goal. To assess the confocal laser scanning microscopy in vivo (CLSM) technique for diagnosing actinic keratosis, psoriasis vulgaris and rosacea vs. the classical histology examination. Study materials. The article describes the results obtained by using the confocal laser scanning microscopy in vivo technique vs. the histology examination in 10 patients with erythematous actinic keratosis, 10 patients with extensive psoriasis and 10 patients with erythematous and papulous rosacea. Results. The article describes diagnostically significant signs of the diseases detected by using the confocal laser scanning microscopy in vivo as well as the potential of this method in terms of diagnosing inflammatory skin diseases.

Reflectance confocal microscopy for monitoring the density of Demodex mites in patients with rosacea before and after treatment

BACKGROUND

Demodex mites seem to serve as a pathogenic trigger in many Demodex-associated diseases such as rosacea. In facial skin of patients with rosacea significantly higher numbers of Demodex mites have been shown compared with healthy controls. Reflectance confocal microscopy (RCM) allows the detection and quantification of Demodex mites in vivo noninvasively. It is hypothesized that a reduction of Demodex mites under rosacea therapy can be monitored by RCM.

OBJECTIVES

To use RCM to monitor the density of Demodex mites in patients with rosacea before and after treatment.

METHODS

In 25 patients with facial rosacea RCM was performed before and after therapy. Mosaics of 5 × 5 mm(2) and 8 × 8 mm(2) were scanned, and the total numbers of mites per follicle and per area were counted, along with the number of follicles per area.

RESULTS

In all patients Demodex folliculorum could be detected and quantified using RCM. RCM showed significant differences pre- and post-treatment (P = 0.0053 for 5 × 5 mm(2) and P < 0.001 for 8 × 8 mm(2)). The mean numbers of mites per follicle were 0.63 (range 0.16-2.28) per 8 × 8 mm(2) area and 0.70 (range 0.11-2.20) per 5 × 5 mm(2) area before treatment, and 0.41 (range 0.074-1.75) and 0.51 (range 0.094-1.70), respectively, after treatment. The corresponding mean numbers of mites were 155 (range 45-446) and 86.2 (range 12-286), respectively, before treatment and 96.2 (range 18-363) and 58.5 (range 12-230), respectively, after treatment.

CONCLUSIONS

By RCM, a reduction in the density of Demodex mites in facial skin of patients with rosacea under therapy, correlating to clinical improvement, can be quantified and monitored noninvasively. Possible reasons for this therapeutic effect are discussed.

Are Demodex mites principal, conspirator, accomplice, witness or bystander in the cause of rosacea?

As the only permanent human ectoparasite, the role of human Demodex mites in health and diseases remains largely unclarified. In view of the ecological interaction between organisms of two different species, a type of commensalism between Demodex mites and humans (the former benefit, the latter unaffected) is most likely, while parasitism occurs temporarily and spatially in the diseased state (the former benefit, the latter harmed). As part of normal skin microbiota, the causal role of Demodex mites in the initiation of rosacea can neither fulfill the classical Henle-Koch's principal nor the advanced criteria proposed by Fredericks and Relman for molecular detection of non-cultivatable microorganisms. Epidemiological analysis using Hill's criteria fails to support the causative role of Demodex mites in rosacea regarding the strength of association, specificity and temporality of association, biological gradient and plausibility as well as clinical coherence, therapeutic experimentation and medical analogy. In application of Rothman's sufficient cause model to evaluate the contribution of Demodex mites to rosacea on a population basis, Demodex mites can be regarded as a non-necessary, non-sufficient causal factor for certain forms of rosacea. Further strategies to dissect the association between Demodex mites and rosacea may include studying the possible existence of more virulent forms of mites with a higher pathogenicity, the endosymbiotic bacteria in certain life periods of mites, the interactions between mites and human hosts or between mites and environment, and to set up ex vivo culture models for Demodex mites.