Bacterial community diversity in human Demodex mites / 中国血吸虫病防治杂志

Objective To investigate the bacterial community diversity in human Demodex mites, so as to provide insights into unraveling the role of human Demodex mites in them caused infectious diseases. Methods From June to July 2023, Demodex mites were collected from the faces of college students in a university in Wuhu City using the adhesive tape method, and the V4 region of 16S ribosomal RNA (16S rRNA) gene and the internal transcribed spacer (ITS) gene of nuclear ribosomal DNA were amplified on an Illumina PE250 high-throughput sequencing platform. Sequencing data were spliced according to the overlapping relations and filtered to yield effective sequences, and operational taxonomic units (OTUs) was clustered. The diversity index of obtained OUTs was analyzed, and the structure of the bacterial community was analyzed at various taxonomic levels. Results A total of 57 483 valid sequences were obtained using 16S rRNA gene sequencing, and 159 OUTs were classified according to similarity. Then, OUTs at a 97% similarity were included for taxonomic analyses, and the bacteria in Demodex mites belonged to 14 phyla, 20 classes, 51 orders, 72 families, and 94 genera. Proteobacteria was the dominant phylum, and Vibrio, Bradyrhizobium and Variovorax were dominant genera. A total of 56 362 valid sequences were obtained using ITS gene sequencing, and 147 OTUs were obtained, which belonged to 5 phyla, 17 classes, 34 orders, 68 families, and 93 genera and were annotated to Ascomycota, Basidiomycota and Chytridiomycota, with Ascomycota as the dominant phylum, and Alternaria alternata, Epicoccum, Penicillium, and Sarocladium as dominant genera. Conclusions There is a high diversity in the composition of bacterial communities in human Demodex mites, with multiple types of microorganisms and high species abundance.

Preferred practice patterns and review on rosacea

Rosacea is a chronic, inflammatory facial dermatosis commonly found in fair skin tone population. Recent studies have shown the increasing prevalence in the dark skin tone population as well. Ocular involvement is very common and can occur without cutaneous features. Common ocular features are chronic blepharoconjunctivitis with eyelid margin inflammation and meibomian gland dysfunction. Corneal complications include corneal vascularization, ulceration, scarring, and rarely, perforation. Diagnosis is largely based on clinical signs, although it is often delayed in the absence of cutaneous changes, particularly in children. The management ranges from local therapy to systemic treatment, depending on the severity of the disease. There is a positive association between demodicosis and rosacea; however, causality is always argued. In this review, we describe the epidemiology, clinical features, and treatment of rosacea and ocular rosacea.

Research progress on the diagnosis and treatment of demodex blepharitis / 国际眼科杂志(Guoji Yanke Zazhi)

Demodex is one of the most common parasites in the human body. It can be classified into demodex folliculorum and demodex brevis based on the parasitic sites. It is an opportunistic pathogenic microorganism, and clinical symptoms may not appear in part of infected people, but the parasite can cause multiple common ocular diseases represented by blepharitis. Its typical symptoms include dry eyes, foreign body sensation in eyes, secretion attached to eyelashes, and ocular surface irritation. The diagnosis of demodex blepharitis should be based on the clinical manifestations and the results of etiological tests. The treatment is related to many kinds of drugs including plant essential oil and physical therapy. At present, diagnosing and treating demodex blepharitis is increasingly sophisticated, but the relationship between demodex infection and its pathogenicity remains unclear. This paper summarizes the current characteristics of demodex and the clinical manifestation, diagnosis, treatment, and existing issues of demodex blepharitis, hoping to provide a reference for future studies in demodex.

Efficacy of optimal pulse technology in the treatment of demodex blepharitis and its effect on ocular surface function / 国际眼科杂志(Guoji Yanke Zazhi)

AIM: To investigate the efficacy of optimal pulse technology(OPT)in the treatment of demodex blepharitis and its influence on ocular surface function.METHODS: A retrospective study was conducted from February 2018 to October 2020. A total of 127 patients(254 eyes)with demodex blepharitis were assigned to the observation group and the control group according to the treatment method. The control group(63 patients, 126 eyes)were given conventional hot compress, eye cleansing and drug therapy. On this basis, the observation group(64 patients, 128 eyes)was treated with OPT. Both groups were given 6wk of continuous treatment. Demodex count, Marx's line scores, meibum character scores, ocular surface disease index(OSDI)scores, non-invasive tear break-up time(NIBUT), non-invasive tear meniscus height(NITMH)and lipid layer thickness(LLT)were compared between the two groups, and safety was evaluated.RESULTS: After 6wk of treatment, demodex count, Marx's line scores, meibum character scores and OSDI scores of the two groups decreased. NIBUT, NITMH and LLT increased. Meanwhile, demodex count, Marx's line scores, meibum character scores and OSDI scores of the observation group were significantly lower than those in the control group. NIBUT, NITMH and LLT were longer/larger than those in the control group(P<0.001). No obvious abnormality of intraocular pressure or conjunctival/corneal injury was observed in either group.CONCLUSION:OPT is effective and safe in the treatment of demodex blepharitis.

Application of fluorescence staining in the detection of Demodex mites in the facial skin / 中华皮肤科杂志

Objective:To analyze the feasibility of fluorescence staining in the detection of Demodex mites. Methods:A single-center split-face study was conducted, and patients with clinically diagnosed rosacea or seborrheic dermatitis were enrolled from the Department of Dermatology, Southern University of Science and Technology Hospital from October 2020 to June 2021. Samples were obtained from the patients′ cheeks by using the squeeze-adhesion method, and Demodex mites were detected by fluorescence staining and direct microscopic examination separately. The detection rate, number of detected Demodex mites, and time for reading slides were compared between the above two detection methods, and the detection rate and number of detected Demodex mites were further compared between the fluorescence staining and standardized skin surface biopsy (SSSB). Chi-square test was used to compare enumeration data, and paired t-test for measurement data. Results:A total of 433 volunteers aged 28.3 ± 3.5 years were enrolled, including 185 males and 248 females. The performance of fluorescence staining was compared with that of direct microscopic examination in 338 pairs of samples obtained by the squeeze-adhesion method, and compared with that of SSSB in 95 pairs of samples obtained by the squeeze-adhesion method. The detection rate of Demodex mites by fluorescence staining was significantly higher (34.0%, 115/338) than that by direct microscopic examination (31.4%, 106/338; McNemar test, P = 0.004) ; among 118 positive samples, the number of detected Demodex mites by fluorescence staining ([8.0 ± 3.3]/cm 2) was also significantly higher than that by direct microscopic examination ([5.5 ± 2.9]/cm 2, t = 9.21, P < 0.001) ; the time for reading slides undergoing fluorescence staining was significantly shorter (8.3 ± 1.2 minutes) than that undergoing direct microscopic examination (17.3 ± 2.5 minutes, t = 38.44, P < 0.001) ; there was favorable consistency in fluorescence staining results between two clinical laboratorians (kappa value = 0.935, P < 0.001). The detection rate of Demodex mites by fluorescence staining (34.7%, 33/95) was higher than that by SSSB (33.7%, 32/95; McNemar test, P < 0.001) ; among 35 positive samples, the number of detected Demodex mites by fluorescence staining was also significantly higher ([11.4 ± 4.2]/cm 2) than that by SSSB ([9.8 ± 4.8]/cm 2; t = 4.77, P < 0.001) . Conclusion:Compared with direct microscopic examination and SSSB, fluorescence staining was more sensitive in the detection of Demodex mites, with better consistency between different observers and shorter time for reading slides.

Efficacy and safety evaluation of three medicated eye patches in Demodex blepharitis: a multicenter, double-blind, randomized controlled clinical trial / 中华实验眼科杂志

Objective:To evaluate and compare the clinical efficacy and safety of three different medicated eye patches in the treatment of Demodex blepharitis. Methods:A multicenter, randomized, double-blind, parallel-controlled clinical trial was conducted.A total of 140 patients (280 eyes) with Demodex blepharitis were recruited in Shanghai Jing'an District Shibei Hospital, Xi'an Fourth Hospital and Kunming First People's Hospital from July 2021 to December 2022.The affected eyes were randomly divided into tea tree oil group, okra oil group, basal fluid control group and metronidazole group by the random number table method.Eye patches containing 20% tea tree oil, 1% okra oil, prepared base solution and 2% metronidazole were applied to the eyes for 28 days by the double-blind method.The count of Demodex was evaluated before treatment and on days 14 and 28 of treatment.Ocular surface symptoms were scored according to Ocular Surface Disease Index (OSDI). The degree of congestion at the eyelid margin and cylindrical dandruff at the root of eyelashes were scored under a slit lamp microscope.The effective rate was calculated according to the comprehensive scores above, and the adverse reactions of the subjects were observed.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of Shanghai Jing'an District Shibei Hospital (No.YL-20200320-05). All the subjects were informed of the significance, purpose and method of the study.Written informed consent was obtained from each subject before any medical examination. Results:All subjects completed the treatment and follow-up, and the loss to follow-up rate was 0%.After 14 and 28 days of treatment, the Demodex count was significantly decreased in all groups compared with before treatment (all at P<0.05). After 28 days of treatment, the number of Demodex in tea tree oil group, okra oil group and metronidazole group were significantly lower than that in basal fluid control group, with statistically significant differences (all at P<0.05). The OSDI score, palpebral margin congestion score and cylindrical dandruff score on 14 and 28 days after treatment in tea tree oil group, okra oil group and metronidazole group were significantly lower than before treatment, showing statistically significant differences (all at P<0.05). After 28 days of treatment, the effective rates of tea tree oil group, okra oil group and metronidazole group were 71.4%, 71.4% and 62.9%, respectively, which were significantly higher than 25.7% in basal solution control group.No serious local or systemic adverse reactions were found during the treatment and follow-up. Conclusions:Eye patches containing tea tree oil, okra oil and metronidazole have significant effects on the treatment of Demodex blepharitis, which can improve the biological environment of the palpebral margin and eliminate the inflammation related to blepharitis.

Advance in the risk factors and pathogenesis of Demodex blepharitis / 中华实验眼科杂志

Demodex is a common small parasite in the human body, with a body length of about 150-350 μm and mainly found in human sebaceous glands and skin hair follicles.In recent years, numerous studies in dermatology and ophthalmology have shown that Demodex is related to the occurrence and development of rosacea, blepharitis and other diseases. Demodex blepharitis has become one of the clinical concerns. Demodex blepharitis is an inflammation in the skin of the eyelid margin caused by Demodex infection.In severe cases, cornea and conjunctiva can be involved, and vision can be affected. Demodex blepharitis is a widespread and easily overlooked disease.Up to 90% of patients with blepharitis are infected with Demodex, and the main pathogenic diagnostic methods are light microscopy and in vivo confocal microscopy.At present, the treatment of Demodex blepharitis is mainly to remove mites by metronidazole and tea tree oil etc.Its risk factors and pathogenesis are not fully understood yet.This article mainly summarized and analyzed the research progress on the risk factors for Demodex blepharitis and its possible pathogenesis at home and abroad in order to provide references for further research and clinical treatment.

Analysis of infection of fungi, bacteria and Demodex in eyelid margin of non-blepharitis and blepharitis / 中华实验眼科杂志

Objective:To observe the distribution characteristics of fungi, bacteria and Demodex in the eyelid margin of patients with blepharitis and without blepharitis at different ages. Methods:A cross-sectional study was conducted.A total of 98 patients diagnosed with anterior blepharitis and 99 patients diagnosed with posterior blepharitis in Henan Eye Hospital from March 2021 to June 2022 were enrolled as anterior blepharitis group and posterior blepharitis, respectively.Additionally, 100 patients with an initial diagnosis of refractive error and 200 patients with vitreous opacity were enrolled during the same period as a non-blepharitis group.All patients underwent examinations for lid margin fungi, bacteria and eyelash Demodex, as well as fungal spores and ciliary Demodex count.The differences in the positive rate and load of palpebral fungi, bacteria and eyelash Demodex were compared between anterior and posterior blepharitis groups, as well as across different ages in non-blepharitis group.This study protocol was approved by the Ethics Committee of Henan Eye Hospital (No.HNEECKY-2019[18]).All patients were informed about the purpose and methods of the study.Written informed consent was obtained from each patient. Results:There were significant differences in the positive rates of bacteria, fungi and Demodex and the load of Demodex in the non-blepharitis group at different ages ( χ2=28.34, 10.36, 51.57, H=35.66; all at P<0.01).The positive rates of palpebral bacteria and ciliary Demodex and the load of Demodex were significantly higher and the palpebral fungi positive rate was significantly lower in the ≥60 years old than in the <60 years old (all at P<0.05).There were significant differences in the positive rates of bacteria and fungi among anterior blepharitis, posterior blepharitis and non-blepharitis groups ( χ2=18.99, 6.36; all at P<0.01).The palpebral bacteria positive rate was significantly higher in anterior blepharitis group than in posterior blepharitis and non-blepharitis groups, and the palpebral fungi positive rate was significantly higher in anterior blepharitis and posterior blepharitis groups than in non-blepharitis group (all at P<0.05).There was no significant difference in the ciliary Demodex detection rate among the three groups ( χ2=0.16, P=0.74).The number of palpebral fungi spores and eyelash Demodex counts were higher in anterior and posterior blepharitis groups than in non-blepharitis group, and the differences were statistically significant (all at P<0.05).The positive rate of palpebral margin bacteria in ciliary Demodex-positive group was 45.7%(156/341), which was significantly higher than 25.6%(40/156) in ciliary Demodex-negative group ( χ2=17.20, P<0.01), and there was no significant difference in the positive rate of palpebral margin fungi between them ( χ2=0.11, P=0.70). Conclusions:In the population with normal eyelid margin, the infection of Demodex and bacteria in lid margin increases and fungal infection decreases in the ≥60 years old.Fungal and bacterial infections are the main sources of palpebral infection in patients with blepharitis, and positive detection of Demodex increases the chance of bacterial infection.

Ivermectina para Demodex folliculorum / Ivermectin for Demodex folliculorum

Objetivo: Evaluar el efecto de la ivermectina sobre Demodex folliculorum in vitro. Materiales y métodos: Bajo microscopio de luz se evaluó el movimiento y anatomía de los parásitos durante 90 minutos. En una lámina portaobjetos no se aplicó nada y sirvió como control. En las otras láminas se aplicó ivermectina al 0.6 y 1%, respectivamente. Resultados: Los parásitos en la placa de control no presentaron cambios en su movilidad ni en su estructura anatómica. Los parásitos a los que se les aplicó ivermectina en concentraciones de 0.6% presentaron alteraciones de movilidad y estructura después del minuto 30 y aquellos sometidos a la concentración al 1% presentaron alteraciones de movilidad y estructura después del minuto 15. Conclusiones: Nuestro estudio demuestra que la ivermectina al 0.6 y 1% afecta la estructura y función de Demodex folliculorum in vitro.

Objective: To evaluate the effect of Ivermectin on Demodex folliculorum in vitro. Materials and methods: Under a light microscope, the movement and anatomy of parasites was evaluated during 90 minutes. On one plate nothing was applied and served as a control. In the other two plates, ivermectin was applied at 0.6% and 1%, respectively. Results: The parasites on the control plate showed no changes in their mobility or anatomical structure. The parasites to which ivermectin was applied in concentrations of 0.6% presented alterations of mobility and structure after the 30th minute and those subjected to the 1% concentration presented alterations of mobility and structure after the 15th minute. Conclusions: Our study shows that ivermectin at 0.6 and 1% affects the structure and function of Demodex folliculorum in vitro.

Efficacy and safety of tea tree essential oil with different concentrations in the treatment of Demodex blepharitis / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To analyze the effectiveness and safety of different concentrations of tea tree essential oil in the treatment of Demodex blepharitis. <p>METHODS: The clinical data of 120 patients(240 eyes)with blepharitis caused by Demodex infection in our hospital from June 2017 to June 2019 were retrospectively analyzed. According to the use of tea tree essential oil concentrations of 10%, 15%, 20% and 25%, patients were divided into 4 groups(group A, group B, group C, group D), each group with 30 people. All patients were given meibomian gland massage, eyelid margin cleaning, and then scrubbed with different concentrations of tea tree oil to clean the eyelid margin. The number of demodex mites, clinical symptom score, clinical sign score, tear film break-up time(BUT), corneal fluorescein staining(FL)and SchirmerⅠtest(SⅠt)were compared before and 2, 4wk after treatment.<p>RESULTS: The number of Demodex mites, clinical symptom score, clinical sign score, BUT, FL and SⅠt were not statistically significant in the four groups before treatment(<i>P</i>>0.05). After treatment, the number of Dmodex mites, clinical symptom score, and clinical sign score in each group were lower than those before treatment, and the number of Demodex mites, clinical symptom score, and clinical sign score after 4wk of treatment in each group were lower than those after 2wk of treatment(all <i>P</i><0.008). After 2 and 4wk of treatment, the number, clinical symptom score and clinical signs score of Demodex mites in group A were the highest, while those in group D were the lowest(all <i>P</i><0.008). After treatment, the BUT of each group was higher than before treatment, and reached the peak in the 4wk. After 2 and 4wk of treatment, BUT among groups was highest in group D and lowest in group A(all <i>P</i><0.008). After treatment, FL and S I t of each group were lower than before treatment, and reached the lowest value in the 4wk. After 2 and 4wk of treatment, FL among the groups was the lowest in group D and the highest in group A(all <i>P</i><0.008). <p>CONCLUSION: Compared with 10% tea tree essential oil, 15% tea tree essential oil can effectively repel mites, relieve clinical symptoms and eye signs in patients with Demodex blepharitis, and is safer than 20% and 25% tea tree essential oils. As the preferred concentration of tea tree essential oil against Demodex blepharitis.

Demodex spp / Dermodex spp

Los ácaros ectoparásitos del género Demodex spp (>140 especies) pertenecen a la familia Demodicidae, superfamilia Cheyletoidea, suborden Prostigmata, orden Trombidiformes, superorden Acariformes. Fueron descritos por primera vez en 1841 por Henle y Berger. El término Demodex deriva del griego: demos = grasa y dex = gusano incrustado. Tienen una longitud de 0.2- 0.4 mm, son transparentes y elongados. Su cuerpo se divide en tres secciones principales: 1) gnatosoma, región anterior, en donde se encuentra la apertura bucal; 2) podosoma, región en la que se encuentran sus cuatro pares de patas; y 3) el opistoma, región caudal o cola. Se adquieren poco después del nacimiento y se consideran parte del microbiota normal de muchos mamíferos, así como también del ser humano, en particular de la unidad pilosebácea. Por lo tanto, se ubican principalmente en el rostro, cuero cabelludo y región superior del tronco. Todas estas áreas corporales se caracterizan por la alta secreción sebácea, alimento primordial para el crecimiento y desarrollo de este ácaro; razón por la cual, además, su densidad aumenta durante la pubertad, periodo cuando proliferan las glándulas sebáceas. Dentro de las especies del género, encontramos exclusivamente en humanos, a D. folliculorum (440 µm), habitando frecuentemente el infundíbulo folicular y D. brevis (240 µm), que se localiza predominantemente en los ductos sebáceos y glándulas tarsales a nivel ocular.(AU)

Correlation analysis of the degree of demodex infection with corneal cell density and ocular surface function in BKC patients / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To investigate the correlation between demodex infection with corneal cell density changes and ocular surface function in patients with blepharo kerato conjunctivitis(BKC). <p>METHODS: Ninety-four patients with BKC(BKC group)at Department of Ophthalmology of our hospital from July 2019 to July 2020 were selected as the research objects, in addition, 80 matched healthy volunteers were selected as control group. The BKC patients were divided into infected group(45 cases)and uninfected group(49 cases)according to whether they were infected with demodex. According to the number of demodex detected in eyelashes, there were 17 cases of suspicious infection, 18 cases of moderate infection and 10 cases of severe infection. All subjects were examined by laser confocal microscopy, and the cell density in the superficial stromal layer of the central cornea and peripheral cornea was calculated. The ocular surface function \〖Schirmer test, Ocular Surface Disease Index(OSDI)\〗, eyelid margin abnormality score, corneal fluorescence stain and tear film break-up time(TF-BUT)of patients with BKC were examined, and the correlation between demodex infection with corneal cell density and ocular surface function in patients with BKC was analyzed. <p>RESULTS: Compared with those in the control group, the cell density in the superficial stromal layer of the central cornea and peripheral cornea was lower in the BKC group(<i>P</i><0.05), and the OSDI, eyelid margin abnormality score and corneal fluorescence stain score were higher(<i>P</i><0.05); the cell density in the superficial stromal layer of the central cornea and peripheral cornea of patients in uninfected group, patients with suspicious demodex infection, moderate demodex infection and severe demodex infection decreased in turn(<i>P</i><0.05), and the OSDI, eyelid margin abnormality score and corneal fluorescence stain score increased significantly in turn(<i>P</i><0.05); the degree of demodex infection was negatively correlated with the cell density in the superficial stromal layer of the central cornea and peripheral cornea in patients with BKC(<i>P</i><0.05), and was positively correlated with OSDI, eyelid margin abnormality score and corneal fluorescence stain score(<i>P</i><0.05).<p>CONCLUSION: The severity of demodex infection has a significant negative correlation with the cell density in the superficial stromal layer of the central cornea and peripheral cornea in patients with BKC, has a significant positive correlation in patients with ocular surface dysfunction.

Correlation analysis of the degree of demodex infection with corneal cell density and ocular surface function in BKC patients / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To investigate the correlation between demodex infection with corneal cell density changes and ocular surface function in patients with blepharo kerato conjunctivitis(BKC). <p>METHODS: Ninety-four patients with BKC(BKC group)at Department of Ophthalmology of our hospital from July 2019 to July 2020 were selected as the research objects, in addition, 80 matched healthy volunteers were selected as control group. The BKC patients were divided into infected group(45 cases)and uninfected group(49 cases)according to whether they were infected with demodex. According to the number of demodex detected in eyelashes, there were 17 cases of suspicious infection, 18 cases of moderate infection and 10 cases of severe infection. All subjects were examined by laser confocal microscopy, and the cell density in the superficial stromal layer of the central cornea and peripheral cornea was calculated. The ocular surface function \〖Schirmer test, Ocular Surface Disease Index(OSDI)\〗, eyelid margin abnormality score, corneal fluorescence stain and tear film break-up time(TF-BUT)of patients with BKC were examined, and the correlation between demodex infection with corneal cell density and ocular surface function in patients with BKC was analyzed. <p>RESULTS: Compared with those in the control group, the cell density in the superficial stromal layer of the central cornea and peripheral cornea was lower in the BKC group(<i>P</i><0.05), and the OSDI, eyelid margin abnormality score and corneal fluorescence stain score were higher(<i>P</i><0.05); the cell density in the superficial stromal layer of the central cornea and peripheral cornea of patients in uninfected group, patients with suspicious demodex infection, moderate demodex infection and severe demodex infection decreased in turn(<i>P</i><0.05), and the OSDI, eyelid margin abnormality score and corneal fluorescence stain score increased significantly in turn(<i>P</i><0.05); the degree of demodex infection was negatively correlated with the cell density in the superficial stromal layer of the central cornea and peripheral cornea in patients with BKC(<i>P</i><0.05), and was positively correlated with OSDI, eyelid margin abnormality score and corneal fluorescence stain score(<i>P</i><0.05).<p>CONCLUSION: The severity of demodex infection has a significant negative correlation with the cell density in the superficial stromal layer of the central cornea and peripheral cornea in patients with BKC, has a significant positive correlation in patients with ocular surface dysfunction.

Roles and action mechanisms of skin microbiota in the occurrence of rosacea / 中华皮肤科杂志

The role of skin microbiota in the occurrence of rosacea remains unclear. This review summarizes several important skin microorganisms that have been reported to be possibly related to the occurrence of rosacea, including Demodex, Bacillus oleronius, Propionibacterium acnes, Corynebacterium kroppenstedtii, etc., and further elaborates on the potential mechanisms of action.

Optimal pulse technology combined with tea tree essential oil paste in the treatment of Demodex blepharitis / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM: To investigate the therapeutic effect of optimal pulse technology combined with tea tree essential oil paste in the treatment of Demodex blepharitis.<p>METHODS: Prospective clinical study. Totally 283 patients(566 eyes)with Demodex blepharitis were selected and randomly divided into three groups. Group A(94 cases, 188 eyes)was treated with optimal pulse technology, group B(96 cases, 192 eyes)was treated with tea tree essential oil paste, and group C(93 cases, 186 eyes)was treated with optimal pulse technology combined with tea tree essential oil paste. After 6wk of treatment, the number of Demodex, subjective symptom score, clinical sign score, tear film rupture time and corneal fluorescein staining were analyzed.<p>RESULTS: There was no significant difference in Demodex count, symptom score, sign score, tear film rupture time and corneal fluorescein staining among the three groups before treatment(<i>P</i>>0.05). After treatment, the number of Demodex among the three groups were significantly reduced(<i>P</i><0.05), and there were significant differences among group C, group A and group B(<i>P</i><0.05). The scores of subjective symptoms and signs of the three groups were significantly improved after treatment(<i>P</i><0.05), and the improvement of group C was more significant than that of group A and group B(<i>P</i><0.05). After treatment, tear break-up time of the group B not significantly improved, tear break-up time that of group C was significantly longer than that of groups A and B(<i>P</i><0.05); Fluorescent staining scores of three groups before and after treatment were significantly improved(<i>P</i><0.05). The statistical results of group C were better than those of groups A and B, but there was no difference among the three groups. No obvious complications occurred in all patients.<p>CONCLUSION: The effect of optimal pulse technology combined with tea tree essential oil in the treatment of acariasis blepharitis is significant, which is significantly better than that of single optimal pulse technology therapy and single use of tea tree essential oil.

Ivermectina para Demodex y condiciones oculares asociadas: revisión de la literatura / Ivermectin for Demodex and related ocular conditions: Review of the literature

Introducción: Existe creciente interés en Demodex y su asociación con condiciones como rosácea, blefaritis, chalazión, meibomitis y queratoconjuntivitis. El manejo con ivermectina ha sido ampliamente reportado tanto en dermatología como en oftalmología. Objetivo: Revisar la literatura para determinar el papel de Demodex en la inflamación de la superficie ocular y el uso de ivermectina en su tratamiento. Diseño del estudio: Revisión de la literatura. Método: Búsqueda de artículos en PubMed con los siguientes términos: Demodex, rosácea ocular, chalazión, rosácea pediátrica, meibomitis, queratoconjuntivitis e ivermectina. Resultados: Se presenta una revisión de generalidades, epidemiología y fisiopatología de la inflamación ocular asociada a Demodex. Se resume el conocimiento actual sobre rosácea y Demodex, y el papel de este como disparador de procesos inflamatorios como chalazión, blefaritis, meibomitis, queratoconjuntivitis y rosácea ocular. Se citan estudios relevantes sobre el manejo de ivermectina en las condiciones mencionadas. Conclusiones: La evidencia reciente otorga a Demodex el papel de un agente disparador de varias condiciones inflamatorias de la superficie ocular. Si bien se requieren más estudios para determinar la efectividad de la ivermectina tópica, el conocimiento actual permite pensar que puede ser útil contra Demodex por su capacidad acaricida

Background: There has been increasing interest in Demodex and its association with conditions such as rosacea, blepharitis, chalazion, meibomitis and keratoconjunctivitis; and ivermectin as a treatment has been reported both in dermatology and ophthalmology. Objective: To review the literature in order to determine the role of Demodex in ocular surface inflammation and the use of ivermectin for its treatment. Study design: Review of the literature. Methods: An article search was done in PubMed with the following terms: Demodex, ocular rosacea, chalazion, pediatric rosacea, meibomitis, keratoconjunctivitis and ivermectin. Results: A review including the epidemiology and pathophysiology of ocular inflammation associated with Demodex is presented. Current knowledge on Demodex and rosacea, chalazion, blepharitis, meibomitis, keratoconjunctivitis and ocular rosacea is summarized. Relevant articles on the use of ivermectin for these conditions are listed. Conclusions: Recent evidence suggests Demodex is a trigger for a number of ocular surface inflammatory conditions. Although more studies are necessary to determine the effectiveness of topical ivermectin, current knowledge supports its acaricidal action against Demodex

IgE AND IgG antibody responses to Dermatophagoides pteronyssinus in dogs with demodicosis and atopic dermatitis / Respostas de anticorpos IgE E IgG específicos à Dermatophagoides pteronyssinus em soros de cães com demodicose e dermatite atópica

Canine demodicosis is a common inflammatory parasitic skin disease caused by Demodex mites. House dust mites, such as Dermatophagoides spp., play an important role in the pathogenesis of canine atopic dermatitis (AD). The goal of this experimental work was to investigate whether demodectic dogs could be previously exposed/sensitized to house dust mites' antigens. First the prevalence of demodicosis in a southeastern region of Brazil was investigated by analyzing clinical files of dogs that were admitted to a Veterinary Hospital. Subsequently, the IgG responses to Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df) and IgE to D.pteronyssinus (Dp) were evaluatedin two groups, AD or demodicosis dogs. Additionally, the major IgE-binding Dp proteins that are recognized by sera from dogs with demodicosis and AD were evaluated. A total of 2,599 clinical files were analyzed to identify the major parasitic skin diseases in dogs from this region, considering the age, sex and breed of the animals. The epidemiological study identified 111 animals with skin diseases; from these 20.7% presented demodicosis. Afterwards, serum samples were obtained from another groups of demodicosis, AD, and healthy dogs, and analyzed for Dp and Df-specific IgG, and IgE antibody levels, Dp IgG avidity by ELISA and IgE-binding Dp-specific proteins by immunoblot. IgG and IgE antibodies to Dp were detected in sera from additional groups of dogs with AD, demodicosis or healthy, with higher IgE levels to Dp in AD than demodectic or healthy dogs. IgG to Df was detected, despite with smaller levels compared to Dp in sera from demodectic dogs, and also in healthy dogs. Immunoblot showed IgE-binding to Dp proteins in sera of dogs with demodicosis and AD; with strong reactivity for the 72 and 116 kDa antigens detected by sera from demodicosis dogs. However, sera from healthy dogs >12 months old also presented reactivity to these bands. In conclusion, the detection of Dp-IgG and IgE antibodies in sera from demodectic dogs indicates previous exposure and sensitization to the house dust mite, respectively, more than cross-reactivity between demodex mites and Dp antigens detected by canine antibodies. Additionally, higher Dp-specific IgE levels were found in dogs with AD compared with those with demodicosis or healthy, suggesting that Dp-specific IgE could better discriminate dogs with AD from healthy ones or even those with demodicosis.

Demodicose canina é uma doença inflamatória comum da pele causada por ácaros do gênero Demodex. Ácaros da poeira doméstica como Dermatophagoides spp. desempenham papel importante na patogênese da dermatite atópica canina (DA). O objetivo desse trabalho experimental foi investigar se cães com demodicose poderiam ser previamente expostos/sensibilizados com antígenos de ácaros da poeira doméstica. A princípio, investigou-se a prevalência de demodicose em uma região sudeste do Brasil, analisando-se prontuários clínicos de cães admitidos em um Hospital Veterinário. Posteriormente, as respostas de IgG a Dermatophagoides pteronyssinus (Dp) e D. farinae (Df) e IgE a D. pteronyssinus (Dp) foram avaliadas em dois grupos, DA ou demodicose. Também foram avaliadas as principais proteínas Dp reconhecidas por anticorpo IgE presente em soros de cães com demodicose e DA. Um total de 2.599 prontuários clínicos foram analisados para identificar as principais doenças parasitárias da pele em cães dessa região, considerando a idade, sexo e raça dos animais. O estudo epidemiológico detectou 111 animais com doenças de pele e destes, 20,7% apresentavam demodicose. Posteriormente, amostras de soro foram obtidas de outros grupos de cães com demodicose, DA ou saudáveis, e analisadas quanto aos níveis de IgG e IgE específicos para Dp e Df, avidez de IgG a Dp por ELISA e proteínas específicas de Dp reconhecidas por IgE por immunoblot. Anticorpos IgG e IgE para Dp foram detectados em soros de grupos adicionais de cães com DA, demodicose ou saudáveis, com níveis mais altos de IgE para Dp na DA do que no soro de animais saudáveis. Níveis de IgG específicos para Df foram detectados, apesar serem menores em comparação com os detectados para Dp em soros de cães demodéticos, e também em cães saudáveis. A análise de immunoblot demonstrou detecção de IgE para proteinas de Dp em soros de cães com demodicose e DA; com forte reatividade para os antígenos de 72 e 116 kDa detectados por soros de cães com demodicose. No entanto, soros de cães saudáveis > 12 meses de idade também apresentaram reatividade a essas bandas. Em conclusão, a detecção de anticorpos Dp-IgG e IgE específicos em soros de cães demodéticos indica exposição prévia e sensibilização aos ácaros, respectivamente, mais do que reatividade cruzada entre ácaros Demodex e antígenos Dp detectados por anticorpos caninos. Além disso, níveis de Dp-IgE específicos mais elevados encontrados em cães com DA, sugerem que esses anticorpos poderiam discriminar melhor cães com DA daqueles saudáveis ou mesmo demodéticos.

Ocular surface diseases related to Demodex and their diagnosis and treatment / 国际眼科杂志(Guoji Yanke Zazhi)

@#Ocular Demodex infection is mainly manifested as ocular surface diseases, including meibomian gland dysfunction, dry eye disease, Demodex blepharitis, chalazion, keratoconjunctivitis,<i> etc</i>. The diagnosis is relatively simple and can be realized under the microscope, but it is easy to be misdiagnosed due to the subjective and objective factors such as similar symptoms, missing examination, experience diagnosis and treatment. There are many treatment methods for ocular Demodex infection, including external tea tree oil and other plant extracts, oral or external drugs, physical therapy(represented by strong pulse light therapy, moxibustion therapy), combined therapy,<i> etc</i>. In this paper, we reviewed the diagnosis and treatment of Demodex related ocular surface diseases, and discussed the latest research trends of this disease.

Effect of wearing overnight orthokeratology lens on the meibomian gland and detection rate of Demodex / 国际眼科杂志(Guoji Yanke Zazhi)

@#AIM:To observe the effect of different time of wearing overnight orthokeratology lens(OOK lens)on the meibomian gland and detection rate of demodex.<p>METHODS:Case-control study. Totally 47(91 eyes)patients who wearing keratoscopy were enrolled from June 2019 to December 2019 in Hanyang Aier Eye Hospital. According to the wearing time, they were divided into short-term group(wearing time <2a)and long-term group(wearing time≥2a). Meanwhile, patients wearing frame glasses with gender, age and diopter matching with the two groups above were selected as the control group. All patients had non-invasive tear film rupture time(NI-BUT)examination, meibomial gland infrared photography, bulbar redness score(BRS), and eyelash sampling.<p>RESULTS: The three groups of NI-BUT were 12.68±4.59s, 12.37±4.97s, 10.45±6.04s,(<i>P</i>>0.05). BRS respectively were 0.99±0.41, 0.90±0.37, 0.84±0.35,(<i>P</i>>0.05). Meibomian gland score for all three groups: 1(0, 1)(<i>P</i>>0.05). In the three groups, the detection rate and quantity of demodex were 42%, 1(1, 2); 39%, 2(1, 2); 33%, 1(1, 2),(<i>P</i>>0.05). Among the patients with corneal staining, 5 were mite positive and 11 were mite negative(<i>P</i>>0.05). Meibomian gland score: 4 eyes were 0 grade, 12 eyes were 1 grade above(<i>P</i>>0.05). Short-term group 6 eyes, long-term group 10 eyes(<i>P</i>>0.05). <p>CONCLUSION:There was no significant effect on meibomian gland, the detection rate and quantity of demodex in patients wearing OOK lens. Whereas no significant relationship between meibomian gland score/ demodex detection rate and corneal staining.

Investigation on Demodex infections among university students in Kunming City / 中国血吸虫病防治杂志

Objective To investigate the prevalence of Demodex infection among students in Kunming Medical University, and identify the factors affecting Demodex infections, so as to provide the evidence for the development of the strategy for the prevention of Demodex infections. Methods A total of 1 463 students from Grade 2014 who studied Medical Parasitology in Kunming Medical University were included in the survey. Demodex was examined in students’facial skin using the cellophane tape method, and the species was identified using microscopy. The students’gender, ethnicity, place of origin and skin type were captured using a questionnaire survey. Results The overall prevalence of Demodex infections was 19.07% (279/1 463) on the facial skin among the university students, and a higher prevalence was seen in girls (21.16%, 183/865) than in boys (16.05%, 96/598) (χ2 =5.965,P <0.05).TheprevalenceofDemodex infectionswas18.33%(66/360)amongminorethnicstudents,andnoethnicity-specific prevalence was seen (P > 0.05). Demodex folliculorum was the predominant species, with a prevalence of 50.54% (141/279), and mild infections were predominant among all infections (96.77%, 270/279), without severe infections seen. Multivariate nonconditional logistic regression analysis revealed that gender and roommates with Demodex infections were risk factors of Demodex infections, and the infection was not associated with ethnicity, place of origin or skin type. There were only 2.53% (37/1 463) of the subjects understanding the knowledge pertaining to the prevention and control of Demodex infection. Conclusions A relatively low prevalence of Demodex infection is detected in the facial skin of students from Kunming Medical University, and Demodex infection is associated with gender and roommates with Demodex infections. Health education pertaining to the prevention of Demodex infections is suggested to be intensified among university students.