Prevalence of Demodex spp. in patients with chronic blepharitis.

Blepharitis is a very common disease in ophthalmology, dermatology and allergy practice. It generally follows a chronic course and is frequently associated with objective and/or subjective symptoms such as epiphora, red eye, dandruff, gritty sensation, itching, burning, photophobia, and blurred vision. The purpose of this study is to analyze the prevalence of Demodex spp. in patients with symptoms of chronic blepharitis. An analytical cross-sectional study was conducted in the period between 2016 and 2020. All patients with symptoms of chronic blepharitis who underwent a parasitological test of eyelashes (Rapitest) in the Dermatology Department of the Hospital Italiano de Buenos Aires were included. Those with previously established blepharitis due to another infectious cause were excluded. We analyzed 972 patients. Sixty percent (n=585) underwent a positive Rapitest for the presence of Demodex spp. Seventy five percent (n=728) were women. There were no significant differences in the prevalence associated with sex (p=0.38). Among the patients positive for Demodex spp., 65% (n=628) were older than 60 years old. The most frequently associated symptom was itching, present in 35% (n=342). A statistically significant decrease in the number of consultations was observed during the cold months of the year (May-June-July-August). Our results show a high prevalence of Demodex spp. in patients with chronic blepharitis. As its presence reveals a direct association with age, we recommend looking for this parasite in this age group.

Prevalence of Demodex folliculorum and Demodex brevis in patients with blepharitis and chalazion.

PURPOSE: Demodex folliculorum and Demodex brevis are common ectoparasites on skin that also can lead to blepharitis and chalazion. The aim of our study is to determine the prevalence of Demodex spp. in eyelashes of patients diagnosed with chronic blepharitis and chalazion. METHODS: This study included 330 patients diagnosed with chronic blepharitis, 70 patients diagnosed with chalazion and 130 volunteers without any ocular problems. Patient eyelashes were examined under a light microscope at magnifications of × 40, × 100 and × 400. Demodex spp. were determined. RESULTS: Parasite prevalence was significantly higher in blepharitis (75.5%) and chalazion groups (70%) compared to the control group (16.2%) (p < 0.001). The prevalence of D. folliculorum in the blepharitis group and D. brevis in the chalazion group was found to be significantly higher compared to other groups (p < 0.05). The average number of mites per eyelash was found to be significantly higher in patients with Demodex positive blepharitis (p = 0.001) and in chalazion patients (p = 0.047) than in the control group. It has been determined that mite positivity increases with age in blepharitis and control groups (p < 0.05). In the group with blepharitis, it was found that mite positivity was significant in the presence of symptoms (p = 0.0001) and Demodex positivity decreased as the education level of individuals increased (p = 0.039). CONCLUSION: The results of the study show that Demodex spp infestations should be considered in chronic blepharitis and chalazion.

Tea tree oil for Demodex blepharitis.

BACKGROUND: Demodex blepharitis is a chronic condition commonly associated with recalcitrant dry eye symptoms though many people with Demodex mites are asymptomatic. The primary cause of this condition in humans is two types of Demodex mites: Demodex folliculorum and Demodex brevis. There are varying reports of the prevalence of Demodex blepharitis among adults, and it affects both men and women equally. While Demodex mites are commonly treated with tea tree oil, the effectiveness of tea tree oil for treating Demodex blepharitis is not well documented. OBJECTIVES: To evaluate the effects of tea tree oil on ocular Demodex infestation in people with Demodex blepharitis. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2019, Issue 6); Ovid MEDLINE; Embase.com; PubMed; LILACS; ClinicalTrials.gov; and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). We used no date or language restrictions in the electronic search for trials. We last searched the databases on 18 June 2019. SELECTION CRITERIA: We included randomized controlled trials (RCTs) that compared treatment with tea tree oil (or its components) versus another treatment or no treatment for people with Demodex blepharitis. DATA COLLECTION AND ANALYSIS: Two review authors independently screened the titles and abstracts and then full text of records to determine their eligibility. The review authors independently extracted data and assessed risk of bias using Covidence. A third review author resolved any conflicts at all stages. MAIN RESULTS: We included six RCTs (1124 eyes of 562 participants; 17 to 281 participants per study) from the US, Korea, China, Australia, Ireland, and Turkey. The RCTs compared some formulation of tea tree oil to another treatment or no treatment. Included participants were both men and women, ranging from 39 to 55 years of age. All RCTs were assessed at unclear or high risk of bias in one or more domains. We also identified two RCTs that are ongoing or awaiting publications. Data from three RCTs that reported a short-term mean change in the number of Demodex mites per eight eyelashes contributed to a meta-analysis. We are uncertain about the mean reduction for the groups that received the tea tree oil intervention (mean difference [MD] 0.70, 95% confidence interval [CI] 0.24 to 1.16) at four to six weeks as compared to other interventions. Only one RCT reported data for long-term changes, which found that the group that received intense pulse light as the treatment had complete eradication of Demodex mites at three months. We graded the certainty of the evidence for this outcome as very low. Three RCTs reported no evidence of a difference for participant reported symptoms measured on the Ocular Surface Disease Index (OSDI) between the tea tree oil group and the group receiving other forms of intervention. Mean differences in these studies ranged from -10.54 (95% CI - 24.19, 3.11) to 3.40 (95% CI -0.70 7.50). We did not conduct a meta-analysis for this outcome given substantial statistical heterogeneity and graded the certainty of the evidence as low. One RCT provided information concerning visual acuity but did not provide sufficient data for between-group comparisons. The authors noted that mean habitual LogMAR visual acuity for all study participants improved post-treatment (mean LogMAR 1.16, standard deviation 0.26 at 4 weeks). We graded the certainty of evidence for this outcome as low. No RCTs provided data on mean change in number of cylindrical dandruff or the proportion of participants experiencing conjunctival injection or experiencing meibomian gland dysfunction. Three RCTs provided information on adverse events. One reported no adverse events. The other two described a total of six participants randomized to treatment with tea tree oil who experienced ocular irritation or discomfort that resolved with re-educating the patient on application techniques and continuing use of the tea tree oil. We graded the certainty of the evidence for this outcome as very low. AUTHORS' CONCLUSIONS: The current review suggests that there is uncertainty related to the effectiveness of 5% to 50% tea tree oil for the short-term treatment of Demodex blepharitis; however, if used, lower concentrations may be preferable in the eye care arena to avoid induced ocular irritation. Future studies should be better controlled, assess outcomes at long term (e.g. 10 to 12 weeks or beyond), account for patient compliance, and study the effects of different tea tree oil concentrations.

Ocular Demodex: a systematic review of the clinical literature.

PURPOSE: There is increasing clinical and research interest in the potential contribution of Demodex to ocular surface disease. The aim of this systematic review was to summarise and synthesise current clinical evidence relating to the aetiology, diagnosis and treatment of ocular Demodex. RECENT FINDINGS: A comprehensive literature search was performed in OVID Medline, OVID Embase, and clinical trial registries, for studies published between 1990 and August 2019, examining Demodex on the ocular surface. The review included primary clinical research studies and systematic reviews of primary clinical research studies, where Demodex was considered in the context of the ocular surface and/or adnexa. Studies were categorised using the National Health and Medical Research Council evidence hierarchy. Risk of bias assessment was performed using validated tools for studies categorised as providing Level I or II evidence. A total of 87 studies were eligible for inclusion, including two systematic reviews. Most studies (60%) were observational, describing the prevalence of ocular Demodex in different clinical populations. There was a high degree of variability in the epidemiological data derived from cross-sectional aetiology studies. There was mostly consistent evidence to support an association between ocular Demodex and chronic blepharitis. Seven diagnostic test-accuracy studies were identified, which considered a range of techniques, including slit lamp examination for cylindrical eyelash collarettes and/or eyelash manipulation techniques, light microscopic evaluation of epilated eyelashes and in vivo confocal microscopy. There is currently no accepted gold-standard diagnostic method for ocular Demodex. For intervention studies, there was one systematic review, 11 published randomised trials, six trial registry entries, and nine case series. Despite a number of recent trials, the appropriate treatment regimen for ocular Demodex (including the optimal criteria and timing of an intervention) is not clearly established. CONCLUSIONS: This comprehensive narrative synthesis has captured the landscape of clinical evidence relating to the prevalence, aetiology, diagnosis and treatment of ocular Demodex. There remain opportunities to enhance understanding of its role in ocular surface disease, best diagnostic approaches and optimal treatment protocols.

The Clinical Use of Eyelash Manipulation in the Diagnosis of Demodex folliculorum Blepharitis.

OBJECTIVES: To compare the efficacy of using an eyelash manipulation technique to the traditional eyelash epilation and subsequent microscopic examination technique, when investigating for the presence of Demodex folliculorum in a clinical setting. METHODS: Four hundred twenty-eight eyelashes of 107 subjects were chosen to compare the quantity of D. folliculorum visible on eyelash manipulation with the slitlamp biomicroscope to that counted on microscopic examination of the same epilated eyelash. One eyelash from each eyelid was rotated with sterile forceps in situ, and the number of D. folliculorum seen emerging from the follicle was counted. The same eyelash was then epilated, and the number of D. folliculorum on the epilated eyelash was counted. Data were analyzed to check for agreement between the two techniques. RESULTS: Intraclass correlation coefficient showed moderately good agreement for assessing the quantity of D. folliculorum (0.78) between the techniques. However, the Bland-Altman plot suggested that consistently higher quantities were found on eyelash manipulation. The overall mean quantity of D. folliculorum was also greater on eyelash manipulation (1.45 mites; range, 0-13 mites) than on microscopic examination of the epilated eyelash (0.81 mites; range, 0-16; P= <0.001). Weighted kappa (κw=0.56) indicated weak levels of agreement between the two methods for addressing severity of infestation. CONCLUSION: Eyelash manipulation exhibited larger quantities of D. folliculorum than complete epilation of the eyelash. In a clinical setting, complete eyelash epilation is not necessary to accurately detect Demodex blepharitis requiring treatment.

In which rosacea patients should Demodex in the eyelashes be investigated?

AIM: The aim of this study was to investigate the relationship between the presence of Demodex on the face and within the eyelash follicles in patients with rosacea. SUBJECTS AND METHODS: This prospective cross-sectional study included 80 participants, 40 patients with rosacea and 40 individuals with no rosacea as controls. The presence of Demodex on the face was assessed by standard superficial skin biopsy. Sixteen eyelashes were epilated from each patient and control. RESULTS: The rate of Demodex infestation and severe infestation on the face in patients with rosacea was significantly higher than the control group. Demodex count within the eyelash follicle was significantly higher in patients with erythematotelangiectatic type rosacea than the control group. There was no increase in blepharitis in rosacea patients but when blepharitis was present, the rate of the presence of Demodex was higher in this group. There was a statistically significant relationship between the presence of Demodex within the eyelashes and itchy eyes in people without blepharitis. CONCLUSION: When at least one Demodex is found on the face in rosacea patients, the eyelashes should be examined for effective treatment of the mite. Itchy eyes may be an important sign of the presence of Demodex in people without blepharitis.

Evaluation of the ocular surface characteristics and Demodex infestation in paediatric and adult blepharokeratoconjunctivitis.

BACKGROUND: To evaluate the ocular surface characteristics and the infestation of Demodex in Chinese paediatric and adult blepharokeratoconjunctivitis (BKC). METHODS: Fifty consecutive patients with BKC and 50 age- and sex-matched healthy subjects were enrolled. Lid margin characteristics and corneal disorders were evaluated under slit-lamp illumination. Four eyelashes were collected from each eye to examine Demodex infestation by light microscopy. RESULTS: Corneal neovascularization (P = 0.001) and scarring (P = 0.040) were significantly worse in children than in adults with BKC, whereas meibum quality was worse in adults (P = 0.008). Diagnosis delay was longer in children with BKC than in adults (2.2 vs 1.2 years, P = 0.022). Demodex infestation was more frequent in subjects with BKC than in healthy subjects (56% vs 26%, P = 0.002). The lid margin inflammation and meibomian gland dysfunction were worse in Demodex-positive subjects than in Demodex-negative subjects with BKC. CONCLUSIONS: Children with BKC had severer corneal disorders compared with adult BKC patients, which may be caused by a long-delayed diagnosis. Ocular demodicosis was more common in subjects with BKC. Ocular Demodex infestation was associated with worse lid margin inflammation and meibomian gland dysfunction.

Ocular Demodex folliculorum: prevalence and associated symptoms in an Irish population.

PURPOSE: To investigate the prevalence of ocular Demodex folliculorum (DF) in an Irish population. To validate a modified Ocular Surface Disease Index questionnaire and employ it to evaluate the relationship between dry eye symptoms and the presence of DF. METHODS: One hundred and fifty-six subjects were enrolled in an epidemiological cross-sectional prevalence study. Each subject completed a novel questionnaire on ocular symptoms and was assessed for the presence of DF. Data was analysed to assess prevalence and to search for significant links between each symptom and DF. RESULTS: An overall prevalence of 68% was found. Total mean number of DF found on microscopic examination was 3.83 mites per subject (range 0-25). The presence of symptoms was higher among individuals with DF (P = 0.04). Itch was found to be the symptom most significantly associated with the presence and number of DF (P = 0.025 and P = 0.035, respectively). The questionnaire showed good internal consistency (Cronbach's alpha; α > 0.7) and good reliability (Intra-class Correlation Co-efficient; ICC > 0.7). The sensitivity and specificity of a positive symptom result using the questionnaire were 70.8% and 46.9%, respectively. CONCLUSION: There is a strong association between the prevalence of DF and symptoms, in particular itchy eyes. However, not all patients with DF will be symptomatic. The newly developed questionnaire is a reliable instrument for measuring change in symptoms over a period of time and suitable for observing patient reported outcomes in interventional treatment studies.

[DEMODEX PARASITES AND CHRONIC BLEPHARITIS].

INTRODUCTION: In the current issue of 'Harefuah', Livny et al present an article on the prevalence of Demodex parasites in patients with chronic blepharitis and healthy controls in Israel. This prospective case controlled study describes the quantitative connection between the number of parasites found on 6-8 sample eyelashes and chronic blepharitis, one of the most prevalent conditions in the general population and especially prevalent in the ophthalmologist office visits. Blepharitis symptoms may vary from being asymptomatic, chronic condition, dry eye, and sometimes even a severe compromise of ocular surface with a morbid impact on patient quality of life. In recent decades, progress was presented in a number of published articles including one meta-analysis that connects blepharitis with Demodex and the treatment of both with tea tree oil. Also, two different species of Demodex were identified which prefer to inhabit different areas of the eyelid. While the presented data do indicate a quantitative connection between Demodex and blepharitis, questions are raised as to whether there is a causative relationship between them? Can Demodex cause chronic blepharitis as an only factor? Or a symbiotic parasite which proliferate in blepharitis by consuming the debris and byproducts of blepharitis? Is it both? Although many theories exist, the answer is yet to be proven, but the consensus today is to combine anti-Demodex products while treating refractory chronic blepharitis.

[PREVALENCE OF DEMODEX PARASITES IN PATIENTS WITH CHRONIC BLEPHARITIS AND HEALTHY CONTROLS IN ISRAEL].

INTRODUCTION: Previous studies demonstrated the potential pathogenic relationship between infestation of the eyelashes by the parasite Demodex and chronic blepharitis, whereas other studies did not demonstrate such relations and concluded that Demodex is a normal eyelid flora. AIMS: This study examines the prevalence of Demodex in patients with blepharitis compared to a healthy control group in Israel, in order to further explore and establish its pathogenic role in cases of chronic blepharitis. METHODS: A case-control study was conducted including 110 participants: 60 patients with chronic blepharitis attending a tertiary medical center and 50 subjects with no signs of blepharitis. Six to eight eyelashes were epilated from each participant and studied microscopically for the presence of Demodex by a blinded examiner. Fluorescein stain was added to the "clean" samples in order to reduce the false negative results. RESULTS: Demodex were identified on the eyelashes of 44 patients with blepharitis (73.3%) and 20 controls (40%) (p<0.001). After adjusting for age, blepharitis was still a significant risk factor for the presence of Demodex (OR=2.96, CI 95% 1.2-7.3). CONCLUSIONS: This study supports previous studies demonstrating pathogenic relationship between Demodex infestation of the eyelashes to chronic blepharitis. The authors recommend epilating 6-8 lashes of patients with blepharitis for microscopic identification of these parasites. Fluorescein stain may have a limited role in the recognition of Demodex in parasite free samples.

[Demodex genus: colonizing parasites of healthy people or mites associated with ocular pathology?] / Ácaros del género Demodex: ¿parásitos colonizadores de personas sanas o asociados a patología ocular?

Demodex folliculorum and Demodex brevis are mites that are responsible for human demodicosis affecting skin and frequently linked to ocular diseasess. The aim of this work was to determine the association between Demodex sp. and eyelid and eyelash diseases and to establish the predisposing factors for acquiring this parasitic disease. Eyelashes from symptomatic and asymptomatic patients (n=72) between 9 and 82 years old were analyzed, where 53% were positive for Demodex sp., of which 66% manifested ocular symptoms and pathologies, blepharitis and dry eye being prevalent. Significant correlations between Demodex and patients over 60 years of age (p<0.001) and between Demodex sp. and dry eye patients / blepharitis (p<0.001) were observed. We consider that it is necessary to search for Demodex sp. especially in those patients suffering from dry eye and blepharitis and/or during immunosenescence in order to implement specific antiparasitic treatments.

The Effect of Demodex Infestation on Blepharitis and the Ocular Symptoms.

OBJECTIVE: This study aimed to determine the frequency of Demodex infestation of eyelashes in patients with and without blepharitis and to determine the effects of Demodex infestation on blepharitis and the ocular symptoms. METHODS: The study included patients with chronic mixed (anterior + posterior) blepharitis who presented to our clinic. Patients with refractive error and no ocular disease were enrolled as the control group. From each participant, a total of 4 eyelashes were removed and were then examined under a light microscope for Demodex infestation. Symptoms, fluorescein tear breakup time, and ocular surface staining pattern were recorded. RESULTS: The prevalence of Demodex infection in the blepharitis group was 67.2%, versus 54.9% in the control group (P=0.18). The incidence of itching in the blepharitis group was significantly higher in the Demodex (+) patients than in the Demodex (-) patients (P<0.001). Fluorescein tear breakup time in the Demodex (+) patients was significantly shorter than in the Demodex (-) patients (P<0.001). There was not a significant difference in the fluorescein staining pattern between the 2 groups (P=0.57). The incidence of advanced stage blepharitis was significantly higher among the Demodex (+) patients (P=0.007). The incidence of cylindrical eyelash dandruff in the blepharitis group was significantly higher in the Demodex (+) patients (P<0.001). There was a significant difference in meibomian gland dysfunction between the 2 groups (P=0.039). CONCLUSION: Demodex infestation must be investigated in patients with advanced stage blepharitis, itching, and shorter than normal fluorescein tear breakup time.

Demodex species in human ocular disease: new clinicopathological aspects.

Demodex brevis and Demodex folliculorum are likely ubiquitous organisms associated with human eyelashes. However, they have also been implicated in the pathogenesis of external ocular diseases. This article reviews the current literature in regards to life cycle, morphology, pathogenesis and treatment of underlying Demodex spp. infestation and outlines the previously undescribed in vivo behaviour of the mites. Images were obtained from the epilation of lashes from 404 patients seen in clinical practice. Epilated lashes were placed on a microscope slide which had been coated with optically clear hypromellose/carbomer gel (Genteal gel, Novartis pharmaceuticals corporation, East Hanover, New Jersey). Adults were identified with either dark field or standard transmission microscopy at 40-100×. Eggs and other life-cycle stages were examined at 250× magnification, with transmission microscopy giving the best image resolution. The life cycle of the mite has been reviewed and simplified according to clinical observations. Clinical signs suggestive of underlying Demodex spp. infestation have been described, and their pathogenesis was explained based on the micrographic digital images obtained. The problem of symptomatic Demodex spp. disease likely reflects an imbalance in the external ocular ecology; however, the role of Demodex spp. as a commensal should not be overlooked. Treatment should not be aimed at total eradication of the mite but rather restoring the ocular ecology to a balanced state. By revisiting the life cycle of the mite, we can identify areas where possible intervention may be effective.

[Diagnostic criteria of demodex blepharitis].

Demodex infestation is a common cause of blepharitis and now is drawing more and more attention from clinicians. Demodex mite is the most common age-related ectoparasite of human being and may be detected from asymptomatic normal population. Furthermore, the pathogenesis of demodicosis remains unclear. Therefore, the commonly accepted diagnostic criteria of demodex infestation related blepharitis have not been established. Herein, we summarize the related studies about ocular demodicosis and comment the debates about the diagnosis of the disease. We also propose diagnostic criteria of demodex blepharitis. (Chin J Ophthalmol, 2017, 53: 648-652).

Over 25 Years of Clinical Experience With Ivermectin: An Overview of Safety for an Increasing Number of Indications.

Although the broad-spectrum anti-parasitic effects of the avermectin derivative ivermectin are well documented, its anti-inflammatory activity has only recently been demonstrated. For over 25 years, ivermectin has been used to treat parasitic infections in mammals, with a good safety profile that may be attributed to its high affinity to invertebrate neuronal ion channels and its inability to cross the blood-brain barrier in humans and other mammals. Numerous studies report low rates of adverse events, as an oral treatment for parasitic infections, scabies and head lice. Ivermectin has been used off-label to treat diseases associated with Demodex mites, such as blepharitis and demodicidosis. New evidence has linked Demodex mites to rosacea, a chronic inflammatory disease. Ivermectin has recently received FDA and EU approval for the treatment of adult patients with inflammatory lesions of rosacea, a disease in which this agent has been shown to be well tolerated. After more than 25 years of use, ivermectin continues to provide a high margin of safety for a growing number of indications based on its anti-parasitic and anti-inflammatory activities.

Recent advances on ocular Demodex infestation.

PURPOSE OF REVIEW: To summarize recent advances on ocular Demodex infestation. RECENT FINDINGS: Demodex infestation is a potential cause of ocular surface inflammation. The pathogenesis of Demodex in eliciting ocular surface inflammation has been further clarified. Cliradex is currently the treatment of choice, it comprises the most active ingredient of tea tree oil, that is terpinen-4-ol, which helps eradicate Demodex mites and reduce ocular surface inflammation. SUMMARY: Ocular demodicosis is a common but overlooked eye disease that manifests a number of morbidities. Demodex folliculorum causes chronic anterior blepharitis whereas Demodex brevis causes posterior blepharitis, meibomian gland dysfunction, recurrent chalazia, and refractory keratoconjunctivitis. The lash sampling and microscopic counting method and in-vivo confocal microscopy are key diagnostic methods. Cliradex shows promising potential to reduce Demodex counts with additional antibacterial, antifungal, and anti-inflammatory actions.

Treatment options for demodex blepharitis: patient choice and efficacy.

BACKGROUND: Demodex mites are microscopic parasites that live around hair follicles or sebaceous glands and may cause chronic blepharitis. The aim of this outcome analysis was to assess the efficacy and patient preferences with regard to the currently recommended treatment options. METHODS: All patients with microscopic evidence for Demodex blepharitis were informed about the currently published treatments and instructed about daily lid hygiene. Additional topical treatment options included tea tree oil (TTO) 5%, a cleansing foam containing 0.02% TTO (Naviblef®), and metronidazole 2% ointment. Systemic treatment options included oral ivermectin 6 mg on day 1 and 14 and metronidazole 500 mg twice daily for 10 days. All patients were reviewed after 2 months for symptoms and for a mite count on 10 epilated lashes. RESULTS: Ninety-four of 96 patients with Demodex blepharitis opted for an additional treatment. The mean mite count after 2 months of treatment were 13.3 with 5% TTO (n=6), 12.0 with 0.02% TTO (n=38), 9.4 with metronidazole ointment (n=5), 12.8 with ivermectin (n=27) and 22.0 with oral metronidazole (n=5). CONCLUSION: While there are several published treatment options available, none of these options seem to be clearly effective in Demodex blepharitis.

Phthiriasis palpebrarum masquerading as blepharitis.

Pthiriasis palpebrarum, a rare condition caused by Phthirus pubis, can mimic blepharitis and manifest as intense itching, inflammation and eyelid redness. We describe a case of Pthiriasis palpebrarum in a young girl with right upper eyelid discomfort. A slit lamp examination revealed eggs on her eyelashes and adult lice on the eyelids' surface. Dermatology consultation confirmed the diagnosis and successful treatment followed. Family evaluation uncovered genital Phthiriasis pubis in her parents, who received appropriate treatment. This report emphasises the importance of accurate diagnosis and management of this masquerading condition by careful slit lamp and microscopic evaluation. It also highlights the significance of comprehensive family history and examination.