"Demodicosis" Mimicking PreSeptal Cellulitis: Severe Periocular and Facial Inflammation Caused by "Normal" Skin Flora.

Due to their relatively high prevalence and commensalism, the pathogenicity of Demodex mites has been debated. Recent data, however, show Demodex to be associated with skin and ocular surface diseases such as rosacea, blepharitis, and keratitis. Here the authors report the first known case, to the best of the their knowledge, of Demodex infestation mimicking preseptal cellulitis in an adult human. A 29-year-old male bilaterally blind from advanced retinopathy of prematurity presented with a 2-month history of right-greater-than-left upper eyelid and periocular/cheek swelling, redness, and ocular discharge that did not resolve with oral antibiotics or oral steroids. Based on MRI findings, biopsies of the right lacrimal gland, right orbital fat, and right upper eyelid preseptal skin were obtained which revealed marked intrafollicular Demodex mite density and budding yeasts in the upper eyelid skin. This case serves to alert clinicians to this entity that may not otherwise be usually considered in ophthalmic clinical practice.

Chronic blepharitis due to Demodex: A prospective study in Sfax (Tunisia).

INTRODUCTION: Chronic blepharitis is a common cause of eye irritation and dryness. They are often treated without regard to causal factors such as parasites which are rarely mentioned. AIM: To describe the role of Demodex in the pathogenesis of chronic blepharitis, to analyze the epidemiological, clinical, diagnostic and therapeutic particularities. METHODS: This is a prospective, case-control study conducted in the mycology parasitology department at the Habib Bourguiba university hospital in Sfax covering 100 cases with chronic blepharitis and 87 control cases. Clinical examination and eyelash removal were performed with direct examination for qualitative and quantitative analysis, before and after treatment. RESULTS: Demodex was significantly more found in patients than in controls (48% vs 13.8%). The quantitative analysis showed a significant difference between the two groups with 52.1% of Demodex (+++) for patients versus 8.3% for controls. Demodex blepharitis were treated with yellow oxid mercure ophthalmic ointment with a good outcome in 81,3%. CONCLUSION: Although it is admitted to be a saprophyte of the skin, a large number of arguments argues for the incrimination of Demodex in the etiopathogenesis of chronic blepharitis, hence the interest of eyelashes examination and a parasitic research in front of any chronic blepharitis resistant to usual treatments. In case of positive research, a specific treatment should be prescribed. Its effectiveness is another argument for the etiological diagnosis.

Hotspot sheep scab management: A community-based regional approach in England.

BACKGROUND: Ovine psoroptic mange (sheep scab), caused by an infestation of the mite Psoroptes ovis, leads to clinical disease, economic loss and severely compromised animal welfare. Here, a community-based approach to the management of scab in three high-risk areas of England is described. METHODS: For each of the 254 farms included in the study, an initial survey of their clinical sheep scab history was followed up by a blood test (ELISA) to detect the presence of antibodies to P. ovis. This facilitated the coordination of treatment across groups of farms in each region. Blood testing was then repeated at the end of the treatment programme. RESULTS: On the first blood test in 2021/2022, 25.6% (±5.5%) of the flocks were positive for sheep scab. On the second test in 2022/2023, 9% (±3.94%) of the flocks tested were positive, showing a highly statistically significant reduction in prevalence overall, but with strong regional variation. LIMITATIONS: generating an understanding of the flock-level nature of the blood test and confidence in its detection of scab where clinical signs were not apparent provided ongoing challenges. CONCLUSIONS: The programme demonstrated that a focused community-based approach can be used to significantly reduce the prevalence of sheep scab in high-risk areas of England. The use of the blood test on all farms allowed the identification of subclinical sheep scab. The programme provides an effective model for sheep scab management on a national scale.

Double-Blind Comparison of Eyelash Epilation Techniques for the Purpose of Demodex folliculorum Mite Retrieval.

OBJECTIVE: Demodex folliculorum blepharitis is typically confirmed with lash epilation and microscopic identification of mites. However, mite counts may vary with the epilation technique. As there is no gold standard to epilating lashes for the purposes of mite counts, the aim of this study was to compare three epilation techniques. METHOD: A prospective randomized double-blind study compared three epilation techniques on lashes with cylindrical dandruff. Techniques included (A) direct pulling of the lash; (B) rotating the lash before epilation; and (C) sliding the cylindrical dandruff away, lash rotation, and epilation. Mean mite counts were analyzed using a repeated-measures analysis of variance. RESULTS: Forty (n=40) participants (20 M: 20 F, mean age of 62.3±17.1 years) revealed similar mite counts between right (1.43±1.74) and left (1.35±1.59) eyes ( P =0.63). A significant difference ( P =0.03) in mite count was noted (technique A: 1.05 ± 1.60; technique B 1.76 ± 1.80; and technique C 1.36 ± 1.54) with technique B yielding the highest mite count ( P =0.04). CONCLUSION: Demodex mite count is a key parameter in establishing infestation or to determine treatment efficacy. This study revealed that rotating the lash before epilation yielded the highest mite count. Future studies should report the epilation technique used to allow for study comparisons.

Role of Topical 5-Fluorouracil in Demodex -Associated Blepharitis.

PURPOSE: The aim of this study was to report clinical observations suggesting the efficacy of topical 1% 5-fluorouracil (5-FU) in treating Demodex -associated blepharitis. METHODS: An observational retrospective review of 13 eyes from 13 individuals with conjunctival neoplastic lesions and concomitant Demodex lash infestation that received topical 1% 5-FU eye drops. Patients underwent slit-lamp examination at each follow-up visit. Clinical photographs of the lash line were obtained after treatment initiation. In a subset of patients, lashes were epilated bilaterally and microscopically analyzed for presence of Demodex mites before and after treatment initiation. RESULTS: The mean age of the population was 68 ± 14 years (range: 30-84 years) and 92% were male. In all 13 patients, a marked reduction in cylindrical dandruff was noted in the treated eye by slit-lamp examination after 2 cycles of 5-FU. There was complete resolution of cylindrical dandruff in 10 of 13 treated eyes compared with 0 resolution of cylindrical dandruff in untreated eyes ( P = 0.0001). In the 6 patients who received epilation, the lashes from the treated eye showed no Demodex , whereas lashes from the fellow untreated eye revealed persistent Demodex . CONCLUSIONS: Topical 1% 5-FU shows efficacy in treating Demodex -associated blepharitis. Further studies are indicated to reproduce our findings and evaluate the potential use of 5-FU as a treatment ingredient.

The effect of phototherapy on Demodex density: a case-control study.

BACKGROUND: Human Demodex mites, Demodex folliculorum and Demodex brevis, are microorganisms that reside in the pilosebaceous units, usually without causing symptoms. Phototherapy has been linked to demodicosis in previous studies. We aimed to determine whether there was an increase in the frequency of demodicosis and Demodex density after 20 phototherapy sessions. METHODS: A case-control study was conducted with 32 participants who received narrowband ultraviolet B or ultraviolet A-1 therapy for various dermatological indications. Standardized skin surface biopsies were performed before and after phototherapy to assess Demodex density. The presence of Demodex-related skin conditions was assessed before phototherapy. A statistical analysis was performed to compare the Demodex densities and prevalence of demodicosis between the baseline and 20th session of phototherapy. RESULTS: No significant change was observed in Demodex density after 20 sessions of phototherapy. The average Demodex density before treatment was 2.75 ± 4.48 (/cm2 ), and after treatment, it was 2.85 ± 4.81 (/cm2 ), indicating no significant difference (P = 0.879). The percentage of patients with demodicosis in at least one region of the face was 28.1% (9/32) before treatment, and after treatment, it was 31.3% (10/32), with no significant difference (P = 1.00). CONCLUSIONS: Our findings contradict previous studies that suggested an increased Demodex density and demodicosis prevalence after phototherapy. The data from previous studies are open to debate due to their selected samples, designs, and interpretations regarding the phototherapy-immunosuppression-Demodex relationship. Larger-scale longitudinal studies conducted on a homogeneous sample are warranted to better understand the relationship between phototherapy and demodicosis.

Topical ivermectin 1.0% cream in the treatment of ocular demodicosis.

PURPOSE: Ocular demodicosis can cause debilitating ocular surface disease. As ivermectin is effective at reducing Demodex proliferation in rosacea, this study investigated the efficacy of topical ivermectin 1.0% cream in treating ocular demodicosis. METHODS: This retrospective single-centre clinical practice chart analysis involved the off-label treatment of patients who had ocular demodicosis with topical ivermectin 1.0 % cream (Soolantra, Galderma Ltd, UK) applied nightly to the lid margins of both eyes for 3 months. Ocular surface health was assessed at baseline when the treatment was prescribed and followed up at 3 and 12 months after baseline. Slit lamp biomicroscopy was used to take digital images of the upper eyelid lashes. Manual image analysis with ImageJ was conducted by a masked assessor to quantify signs of ocular demodicosis including the number of lashes with collarettes, with visible Demodex tails and with follicle pouting. RESULTS: Data from a total of 75 patients with ocular demodicosis were analysed for this study (mean age 66.6 ± 13.9 years, 44 female). The numbers of lashes with collarettes (Median [Interquartile range]: 8 [4-13] at baseline to 0 [0-2] at the final visit, p < 0.001) and lashes with follicle pouting (3 [1-5] at baseline to 0 [0-1.8] at the final visit, p < 0.001) decreased with treatment. Any sign of lashes with visible tails was eliminated by the final visit (p < 0.007). Fluorescein staining severity score also improved, particularly from baseline (1 [0-2]) to the second visit (0 [0-1], p < 0.001). CONCLUSIONS: The findings of this study show evidence for the efficacy of a 3-month course of topical ivermectin 1.0% cream in treating ocular demodicosis as indicated by reduction in collarettes, follicle pouting and visible Demodex tails. More research is warranted to improve the diagnosis, management and monitoring of this condition which is often overlooked or misdiagnosed.

A Delphi approach to establishing consensus on best practice for the diagnosis and treatment of Demodex blepharitis.

Demodex blepharitis does not have agreed standardized guidelines. The aim of this study was to classify signs and symptoms and to develop appropriate management strategies for Demodex blepharitis from a consensus of expert advice. METHODS: A total of 11 anterior segment experts (ophthalmologists, optometrists and a contact lens optician) working in the United Kingdom participated in a modified 2-round Delphi panel. A mixed-methods approach was adopted and a survey questionnaire for round 1 was formulated, constructed from information in the available literature. Based on panel responses from round 1, feedback was provided and a round 2 questionnaire was formulated. More than two-thirds majority (72%) was used for consensus building. RESULTS: Based on the clinical presentation of signs and symptoms along with associated conditions and risk factors, a diagnostic algorithm was proposed for the clinical investigation of Demodex blepharitis. A treatment algorithm was also proposed with first-line and second-line treatment recommendations for Demodex blepharitis. CONCLUSION: The recommendation from this study provides the first effort in formulating clinical diagnostic algorithm and management guidelines for Demodex blepharitis. The guidelines include appropriate magnification on the slit lamp, associated signs, symptoms, risk factors and suggested management options. These guidelines can be used in a routine eyecare setting to encourage eyecare practitioners in tailoring the investigation and management of Demodex blepharitis.

Topical ivermectin ointment treatment of Demodex blepharitis: a 6-year retrospective study.

BACKGROUND: To evaluate the efficacy of topical ivermectin 1% ointment, for the treatment of Demodex blepharitis. METHODS: A retrospective study was designed to review electronic medical records of patients seen between January 2017 and December 2022, who had a diagnosis of Demodex blepharitis, treated with topical ivermectin 1% with at least 6 months of follow-up (Centro de Ojos Quilmes, Buenos Aires, Argentina). The presence of collarettes was graded from 0 to 4. An imaging system (Keratograph) was used, to evaluate tear meniscus height (TMH), non-invasive tear break-up time (NIKBUT), and degree of conjunctival redness. In addition, the ocular surface disease index (OSDI) test was performed. Results were compared before and after ivermectin treatment, which was performed once a day for 2 months. RESULTS: A total of 2157 patients (4314 eyes) were included. The mean age was 50.43 ± 15.3 years, and the follow-up time was 26.1 ± 8.5 months. No one discontinued treatment due to intolerance, although 14 cases (0.6 %) reported occasional discomfort. The grade of collarettes decreased with statistical significance, from 3.37 ± 0.7 to 0.1 ± 0.3 (p < 0.01), as well as conjunctival redness from 1.32 ± 0.3 to 0.94 ± 0.4 (p < 0.01) and OSDI score from 58.74 ± 17.9 to 17.1 ± 10.5 (p = 0.02). TMH and NIKBUT improved without statistical difference. CONCLUSION: Treatment with ivermectin 1% topical ointment, once daily for 2 months, was effective in reducing the presence of collarettes and in improving symptoms in patients with Demodex blepharitis.

Correlation between Demodex species in primary and recurrent chalazia.

OBJECTIVE: To determine the correlation between the infestation by species of Demodex spp. and the occurrence of primary and recurrent chalazia. METHODS: Prospective and observational study. Patients with primary or recurrent chalazia were included. Eyelash samples were taken to determine the microscopic presence of Demodex spp. The correlation between the recurrence of the chalazia and the infestation by Demodex spp. mites was determined using Spearman's rank correlation coefficient test. RESULTS: Sixty-eight adult patients diagnosed with chalazia were included. In 63.2% of the total cases, the presence of one or more parasites of the genus Demodex spp. was documented. In the quantitative parasitological study, it was found that 25% of all cases presented infestation by Demodex spp. defined by an index greater than or equal to 0.5 parasites per eyelash. The most frequently found species was Demodex folliculorum. Of the 14 patients with recurrent chalazia, 50% presented infestation by Demodex spp. and in 91.7% of the cases the infestation was by D. folliculorum. There is a positive, directly proportional correlation between these factors (rθ=+0.665, P<.05). In the group of patients with primary chalazion, only 18.5% presented infestation by Demodex spp., and in 81.6% of these cases it was caused by D. folliculorum. There is a non-statistically significant correlation between these two factors. CONCLUSION: There is a direct, high and statistically significant correlation between the recurrence of the chalazion and the infestation by Demodex spp., there is no statistically significant correlation between the primary chalazia and the presence of Demodex spp.

The Use of Digital PCR for the Diagnosis of Demodex Blepharitis.

PURPOSE: This was a pilot study to evaluate the efficacy of digital polymerase chain reaction detection of Demodex in eyelid margin swabs for the diagnosis of Demodex blepharitis. This study aims to explore the possibility of digital polymerase chain reaction detection to improve the diagnostic accuracy of Demodex blepharitis detection. METHODS: Volunteers were prospectively recruited and classified by experienced doctors into suspected Demodex blepharitis or healthy controls using slit-lamp evaluation of the eyelid margin and an inquiry about symptoms. Three eyelashes from each eyelid were epilated from participants in each group for microscopic observation and mite counting. Then, swabs from the eyelid margins of each eye were collected after the eyelashes were epilated and stored at -80 °C for future DNA extraction and digital polymerase chain reaction detection. The positive or negative results of both methods were compared for diagnostic accuracy, and the Kappa value was also calculated to evaluate their consistency. RESULTS: The accuracy of the digital polymerase chain reaction detection was 71.6% and that of the mite counting method was 75%. Their combined accuracy was improved to 77.3%. The Kappa value of the two methods was 0.505, indicating moderate consistency. CONCLUSION: Digital polymerase chain reaction detection of Demodex from ocular surface swabs was painless and noninvasive and is a potentially accurate quantitative method available for diagnosing Demodex blepharitis. This method is also complementary to the conventional mite counting method, particularly when a sufficient number of eyelashes cannot be effectively epilated.

Comorbidity of Ocular and Facial Demodicosis.

PURPOSE: To determine the association between ocular and facial demodicosis, and the effect of facial treatment on ocular demodicosis. DESIGN: Prospective clinical cohort study. METHODS: Ocular demodicosis outpatients from a tertiary medical center were enrolled from April to December 2020. The diagnosis was based on epilation of 4 eyelashes from each upper eyelid. High ocular Demodex load (ODL) was defined as ≥8 mites per eye. Facial infestation was assessed by direct microscopic examination, with facial Demodex overgrowth (FDO) defined as a density >5 mites/cm2. All patients were prescribed 3 months of ocular treatment, and FDO patients received dermatologic treatment. RESULTS: Eighty-nine patients were enrolled. Among those that completed the treatment course, 39 presented high ODL. Lower cylindrical sleeve counts were found in low ODL patients (low ODL vs high ODL: 8 vs 14, P = .009). FDO was less prevalent in this group (49% vs 77%, P = .012). The Ocular Surface Disease Index score decreased in patients without FDO (20.0 ± 17.1 to 14.0 ± 16.6, P = .027) after 3 months of topical tea tree oil treatment. Topical ivermectin treatment on the facial skin provided a higher ocular Demodex eradication rate in FDO patients (76% vs 16%, P < .001). CONCLUSION: Concurrence of ocular and facial demodicosis is common, especially in cases of severe ocular demodicosis. Although ocular treatment alone is effective for patients with ocular demodicosis only, cotreatment with topical ivermectin on the facial skin enhances ocular Demodex eradication in patients with comorbid facial Demodex overgrowth.

Chicago sky blue gel for better visualization of Demodex in patients with Demodex blepharitis.

Background: Demodex blepharitis is a common chronic disease. The number of mites is associated with ocular discomfort. The accurate number derived from well-stained specimens is, hence, in favor of diagnosing, monitoring, and determining treatment responses. Methods: A cross-sectional study was conducted between April and July 2022 at the dermatology and ophthalmology clinic, Walailak University, Thailand. Adult participants with clinical suspicion of Demodex blepharitis were recruited. We examined eyelashes under light microscopy to quantify the number of Demodex mites before and after adding CSB gel. The mite counts, evaluated by an untrained investigator and an experienced investigator, were recorded and compared. Results: A total of 30 participants were included for final analysis, among which 25 (83.3%) were female. The median age was 64.0 years (IQR, 61.0-68.0). The median Demodex counts evaluated by the experienced investigator before and after adding CSB gel were 1.0 (IQR, 0.0-1.0) and 2.5 (IQR, 2.0-3.0), respectively (p < 0.001). Moreover, the median Demodex counts evaluated by the untrained investigator before and after adding CSB gel were 1.0 (IQR, 0.0-1.0) and 2.0 (IQR, 1.0-3.0), respectively (p < 0.001). The correlation coefficient between Demodex counts after the addition of CSB counted by the experienced investigator and those counted by the untrained investigator was 0.92 (p < 0.001). CSB gel is a promising product to identify and quantify the number of Demodex mites. The findings supported the consideration of CSB gel as one of the diagnostic stains.

What's Eating You? Tropical Rat Mite (Ornithonyssus bacoti).

The tropical rat mite (Ornithonyssus bacoti) commonly infests wild and pet rodents, but they are not host specific. Bodily contact with wild or domesticated rodents is the most common source of infestation. Mites can live off many mammal hosts for a long period of time; therefore, living in quarters infested by mice can lead to mite exposure. Human infestation presents as urticarial, pruritic, cutaneous lesions that may be misdiagnosed as an arthropod bite, an infection, or contact dermatitis. Symptomatic relief of pruritus can be provided with a topical corticosteroid or antihistamine. The most effective treatment is an antiparasitic, such as permethrin cream, as well as extermination of rodents, mites, and any other pests in the patient's living space.

Development of the first PCR for detection of Psoroptes ovis var. cuniculi infection and its comparison to microscopic examination and serological assay in rabbits.

Psoroptes mites are the common ecto-parasites of wild and domestic animals worldwide, which causes considerable economic losses in livestock industry. Microscopy is deemed to be the 'gold standard' for the diagnosis of Psoroptes mite infection but it has poor sensitivity for low mite infections and/or sub-clinical infections. To overcome these shortcomings, we screened four genes to develop a sensitive and specific PCR for the detection of Psoroptes mite infection in rabbits, and confirmed its practicability in detecting early infection and monitoring treatment outcome with traditional microscopy and serological tests. Results showed that PCR assay targeting ITS2 (ITS2-PCR) had a high specificity and sensitivity (detection limit: 40.3 pg/µL DNA) for detecting P. ovis DNA. In rabbits artificially infected with P. ovis, all three diagnostic tests showed the same detection rate from 14 days post infection (dpi) to 42 days dpi. However, these diagnostic tests behave differently at 7 dpi and after treatment: at 7 dpi, the detection rate of ITS2-PCR was higher than rPsoSP3-based iELISA and traditional microscopy (ITS2-PCR: 88.9%, rPsoSP3-iELISA: 77.7%, microscopy: 33.3%); at 7 days post treatment (dpt), positivity rates of ITS2-PCR and microscopy rapidly decreased to 0.00% and 11.1%, whereas rPsoSP3-iELISA remained 100% positive rate. Furthermore, the comprehensive comparisons of diagnostic performance and features of three diagnostic tests at 7 dpi were performed. Compared to ITS2-PCR or rPsoSP3-iELISA, microscopy had the lowest sensitivity, and the agreement between these assays was low (κ < 0.3). Field study showed that ITS2-PCR showed a higher detection rate than microscopy (19.4% and 11.1%, respectively). Our results suggested that the ITS2-PCR developed in this study provided a new laboratory tool for diagnosis of P. ovis var. cuniculi infection, and it had advantages over microscopic examination in detection low-level mite infections and serological assay in monitoring treatment outcome.

Demodex Blepharitis: A Comprehensive Review of the Disease, Current Management, and Emerging Therapies.

ABSTRACT: Demodex blepharitis is a common disease of the eyelid, affecting approximately 25 million Americans. This article reviews what is known about the mechanisms and impact of Demodex blepharitis, risk factors, signs and symptoms, diagnostic techniques, current management options, and emerging treatments. Demodex mites contribute to blepharitis in several ways: direct mechanical damage, as a vector for bacteria, and by inducing hypersensitivity and inflammation. Risk factors for Demodex blepharitis include increasing age, rosacea, and diabetes. The costs, symptom burden, and psychosocial effects of Demodex blepharitis are considerable. The presence of collarettes is pathognomonic for Demodex blepharitis. Redness, dryness, discomfort, foreign body sensation, lash anomalies, and itching are also hallmarks of the disease. Although a number of oral, topical, eyelid hygiene and device-based options have been used clinically and evaluated in studies for the management of Demodex blepharitis, none have been FDA approved to treat the disease. Recent randomized controlled clinical trials suggest that lotilaner ophthalmic solution, 0.25%, is a topical treatment with the potential to eradicate Demodex mites and eliminate collarettes and eyelid redness for an extended period.