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

Las especies Demodex folliculorum y Demodexbrevis, responsables de la demodicosis humana, afectan la piel y en ocasiones están vinculadas con afecciones oculares. El objetivo de este trabajo fue conocer si existe asociación significativa entre la presencia del ácaro y de patologías palpebrales, y el papel de factores como la edad y el sexo de los pacientes. Se analizaron las pestanas de un conjunto de pacientes sintomáticos y asintomáticos (n = 72) de entre 9 y 82 años. El 53% de los pacientes fueron positivos para la presencia del ácaro Demodex. De ellos, el 66% manifestó síntomas o patologías oculares, dentro de las cuales la blefaritis y el ojo seco resultaron prevalentes. Se observaron asociaciones significativas tanto entre la presencia de este ácaro y una edad mayor de 60 años (p < 0,001), como entre la presencia del ácaro y ojo seco o blefaritis o ambos (p <0,001). Consideramos necesaria la búsqueda de Demodex sp. en pacientes con síndrome de ojo seco o blefaritis, especialmente durante la inmunosenescencia, a fin de instaurar tratamientos antiparasitarios específicos.

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.

Demodex spp en pacientes con blefaritis crónica / Demodex spp in chronic blepharitis patients

Background: Blepharitis is a very common disease in the ophthalmologic practice generally taking a chronic course with intermittent exacerbations. Several studies have linked the presence of Demodex folliculorum with chronic blepharitis, since the mite has the capacity to perpetuate the follicular inflammatory process. The prevalence of infection by Demodex spp. is variable depending on the population. In Paraguay, information on the frequency of the infestation in patients with chronic blepharitis is not available. Aim : To determine the frequency of Demodex spp, and the ocular microbiota in patients with chronic blepharitis attending the Department of Ophthalmology at the Teaching Hospital of the National University of Asuncion. Patients and Methods: Consecutively, 28 patients with chronic blepharitis, who agreed to participate in the study, were included. Eyes lashes from the upper and lower eyelids were extracted for immediate mite search by direct observation under a light microscope. Samples from eyelids were taken with Kimura spatula and then cultured on blood agar and in enrichment media and incubated in 5% CO2 at 35° C for 72 hours. Results: Among participants, females were more frequent (64%), the age ranged from 17 to 87 years (mean: 38.0; SD: ±13.5 years). The prevalence of Demodex sp was 54%. Bacteria were isolated 92.9% of cases, most frequently coagulase-negative staphylococci (75%). No association was found between socio-demographic or clinical characteristics and the presence of Demodex sp. Conclusion: The observed high prevalence of infestation by Demodex spp in patients with chronic blepharitis is consistent with other studies.

Introducción: La blefaritis es una enfermedad muy común en la práctica oftalmológica, generalmente de curso crónico con exacerbaciones intermitentes. Varios estudios han relacionado la presencia del Demodex folliculorum con la blefaritis crónica, por su capacidad potencial de perpetuar el proceso inflamatorio a nivel folicular. La frecuencia de D. folliculorum varía de acuerdo a la población. Objetivo: Determinar la presencia de Demodex spp y, caracterizar la microbiota ocular en pacientes con blefaritis crónica y dar a conocer estos resultados. Pacientes y Métodos: Las muestras fueron obtenidas de pacientes que consultaron en la Cátedra de Oftalmología del Hospital de Clínicas de la Universidad Nacional de Asunción (UNA). Fueron incluidos en forma consecutiva 28 pacientes con blefaritis crónica que accedieron a participar en forma voluntaria en el estudio. Se extrajeron las pestañas del párpado superior e inferior de los pacientes para la búsqueda inmediata del ácaro por observación directa bajo el microscopio óptico. Para el cultivo de microorganismos se tomaron muestras del párpado con espátula de Kimura, las que fueron cultivadas en agar sangre y en medios de enriquecimiento e incubadas en CO2 al 5% a 35°C durante 72 h. Resultados: El sexo femenino fue más frecuente (64%), el rango de edad estuvo entre 17 y 87 años con una media de 37,9 ± 13,5. Se observó la presencia de Demodex sp en 54% y aislamiento de bacterias en 92,9%; Staphylococcus coagulasa negativa fue el más frecuente (75%). No se encontraron asociaciones entre las características socio-demográficas o clínicas y la presencia de Demodex sp. Conclusión: La alta infestación por Demodex spp observada en los pacientes con blefaritis crónica coincide con otros estudios.

Determinación de índice de infestación por Demodex spp, en pacientes con blefaritis crónica y en pacientes sin otra patología ocular / Measurement of the index of infection by Demodex spp in patients with chronic blepharitis and in patients without other ocular diseases

Infestation by Demodex spp. in the palpebral edge follicles in humans is common. However, these mites are not routinely diagnosed in patients with or without ocular pathologies in Chile and their relevance is unclear. One of the eye diseases most related to infestation by Demodex spp. is blepharitis, a chronic inflammation of the eyelid margin with intermittent exacerbations, which is very common in ophthalmic practice. Its management is prolonged treatment, which is often ineffective, leading to relapses and frustration of patient and treating physician. Blepharitis can be typed by its etiology into various types, one of them is caused by Demodex folliculorum and another species, D. brevis. Objective: The overall objective was to detect the presence and estimate the rate of infestation of Demodex spp. in healthy subjects and in patients with ocular pathology such as blepharitis, bacterial conjunctivitis, chalazion, and stye. Patients and Methods: Samples of tabs from both lower eyelids of ophthalmologically healthy patients (23) and patients with ocular pathologies (9) were mounted in immersion oil as described in literature, then visualized with a 10x objective and confirmed with 40x objective. Results. Detection rates of eggs, nymphs or adults of Demodex spp. in patients with and without ophthalmological problems were above and below 0.5 mites per tab, respectively. D.folliculorum was the species most frequently found. Discussion: The results are consistent with the international literature on both the rate of infestation as the predominant species. Conclusion: This paper is the first study in Chile on this subject and represents a significant contribution to ophthalmic clinical diagnosis and treatment of patients with this disease.

La infestación por Demodex spp. en los folículos del borde palpebral en humanos es frecuente; no obstante, en Chile no se diagnostica de rutina la presencia de estos ácaros en pacientes sin o con patologías oculares por lo cual no se conocen aspectos de esta parasitosis. Una de las patologías oculares que más se relaciona con infestación por Demodex spp. es la blefaritis, enfermedad muy común en la práctica oftalmológica, que cursa con inflamación crónica del borde palpebral, con exacerbaciones intermitentes de los síntomas. Su manejo suele llevar mucho tiempo frecuentemente ineficaz, con múltiples recaídas que terminan desmoralizando al paciente y, al médico que las trata. De acuerdo a la etiología, se caracterizan varios tipos de blefaritis y una de ellas es asociada a Demodexfolliculorum, existiendo también la especie D. brevis. Objetivo: Detectar la presencia y calcular el índice de infestación de Demodex spp. en pacientes sanos y en pacientes con alguna patología ocular como blefaritis crónica, conjuntivitis bacteriana, chalazión y orzuelo. Pacientes y Métodos: Se tomaron muestras de pestañas desde el párpado inferior de ambos ojos en pacientes oftalmológicamente sanos23 y pacientes con patologías oculares9 las que fueron montadas en aceite de inmersión según técnica descrita en la literatura, visualizadas con objetivo 10x y confirmadas con objetivo 40x. Resultados: Se encontró la presencia de huevos, ninfas y ejemplares adultos de D. folliculorum y D. brevis, tanto en pacientes normales como en pacientes oftalmológicos siendo el índice de infestación menor a 0,5 ácaros por pestaña en los pacientes sanos y mayor o igual a 0,5 en pacientes oftalmológicos. La especie más frecuentemente encontrada fue D. folliculorum. Discusión: Los resultados encontrados coinciden con la literatura internacional tanto en el índice de infestación como en la especie predominante. Conclusión: Este trabajo constituye el primero realizado en Chile en esta temática, de acuerdo a la literatura revisada, lo cual constituye un gran aporte al diagnóstico clínico oftalmológico con implicancias en el tratamiento de estos pacientes.

Demodex folliculorum on the eyelash follicule of diabetic patients / Demodex folliculorum nos cílios de pacientes diabéticos

PURPOSE: To compare the prevalence of Demodex folliculorum on the eyelashes of patients with proliferative diabetic retinopathy and healthy voluntaries. METHODS: Type 2 diabetic patients with proliferative retinopathy and age- and gender-matched healthy voluntaries (group control) underwent a slit lamp examination which three eyelashes containing cylindrical dandruff were removed from each lid by fine forceps. The lashes were dyed with fluorescein and the presence of Demodex folliculorum was verified by direct visualization under a light microscope. The mites were recognized based on its morphology and peculiar movement. The results were expressed in "positive" when at least one mite on one lash was found and "negative" when no mite was identified. The Chi-square test was used for comparing mites' presence in both groups. RESULTS: Forty-two patients were included in each group. The age ranged from 50 to 60 years old, with a mean of 56.4 ± 5.2 years. The male:female ratio was 0.6:1. There was no statistically significant difference with regard to age and gender in both groups (p>0.05). Demodex folliculorum was significantly more prevalent in diabetic patients (54.8 percent) than in control patients (38.1 percent) (p=0.048). CONCLUSION: Demodex folliculorum was more prevalent in diabetic patients than in healthy voluntaries, independently of gender and age.

OBJETIVO: Comparar a prevalência de Demodex folliculorum nos cílios de pacientes com retinopatia diabética proliferativa e voluntários normais. MÉTODOS: Pacientes com diabetes mellitus tipo 2 apresentando retinopatia proliferativa e voluntários normais com mesma distribuição de sexo e idade (grupo controle) foram submetidos a exame em lâmpada de fenda. Três cílios com secreção "em colarete" foram removidos de cada pálpebra com pinça delicada. Os cílios foram corados com fluoresceína e a presença de Demodex folliculorum foi verificada por visualização direta através de microscópio de luz. As larvas foram reconhecidas baseadas em sua morfologia e movimentos peculiares. Os resultados foram expressos em "positivo" quando foi encontrada pelo menos uma larva em um cílio e "negativo" quando nenhuma larva foi encontrada. O teste de Chi quadrado foi utilizado para comparar a presença das larvas nos dois grupos. RESULTADOS: Quarenta e dois pacientes foram incluídos em cada grupo. A idade variou de 50 a 60 anos com média de 56,4 ± 5,2 anos. A relação masculino:feminino foi de 0,6:1. Não houve diferença estatisticamente significante com relação ao sexo e idade entre os dois grupos (p>0,05). Demodex folliculorum foi significantemente mais prevalente em pacientes com diabetes (54,8 por cento) que no grupo controle (38,1 por cento) (p=0,048). CONCLUSÃO: Demodex foliculorum foi mais prevalente em pacientes diabéticos que em voluntários normais, independentemente do sexo e da idade.

Prevalencia de infección por Demodex folliculorum en pacientes que acuden a consulta general de oftalmología / The prevalence of Demodex folliculorum infection in patients attending a general ophthalmological consultation

Objetivos Determinar la prevalencia de infección por Demodex folliculorum en pacientes que asisten a consulta general de oftalmología, y su asociación con blefaritis. Métodos Estudio descriptivo de prevalencia. En forma aleatoria se seleccionaron 128 sujetos que asistieron al Centro Oftalmológico Virgilio Galvis y se determinó la presencia de Demodex folliculorum en 4 pestañas de cada uno. Resultados La prevalencia de infección por Demodex folliculorum fue 42,1 % (n= 54). Se diagnosticó blefaritis en el 38,3 % de los pacientes (n=49) y el 63,2 % de ellos (n=31) fueron positivos para D. folliculorum. En el grupo sin blefaritis (n=79) solo el 29,2 % de los individuos tenían el ácaro (n=23) (p=0.0003). Además se encontró una mayor cantidad de parásitos en los pacientes con blefaritis (índice de carga parasitaria 12,7 vs 5,1 (p=0.0001). El 25 % (n=32) de los participantes presentaban descamación en forma de cilindros y en estos el 96,9 % tenían el ácaro (n= 31), mientras que en los sujetos que no tenían cilindros (n=96) el ácaro estuvo presente solo en el 24 % (n=23). Conclusiones El Demodex folliculorum es un parásito que se encuentra en personas sin lesiones oculares, pero que es más frecuente y presenta una mayor carga parasitaria en pacientes con blefaritis. Nuestros resultados sugieren la necesidad de investigar la presencia de Demodex folliculorum en todo paciente con blefaritis y especialmente en los casos en que se observe presencia de descamación en forma de cilindros en las pestañas.

Objectives Determining Demodex folliculorum infection prevalence in patients attending general ophthalmological consultation and such infection's association with blepharitis. Methods This was a descriptive study of such prevalence. 128 subjects who attended the Virgilio Galvis Eye Centre were randomly selected and the presence of D. folliculorum was determined in 4 eyelashes taken from each of them. Results D. folliculorum infection prevalence was 42.1 % (n=54); blepharitis was diagnosed in 38.3 % of the patients (n=49) and 63.2 % of them (n=31) were positive for D. folliculorum. Only 29.2 % of the individuals in the group without blepharitis (n=79) had mites (n=23) (p=0.0003). A higher number of parasites was found in patients with blepharitis (12.7 parasitic load index cf 5.1; p=0.0001); 25 % (n=32) of the participants had scaling in the form of cylinders and 96.9 % of these had the mites (n=31), whereas the mite was only present in 24 % (n=23) of subjects who had no cylinder-type scaling (n=96). Conclusions Demodex folliculorum is a parasite found in people without ocular lesions; however, it is more frequent and has a higher parasite burden in patients with blepharitis. Our results suggested the need for investigating the presence of D. folliculorum in all patients suffering from blepharitis, especially in cases where cylinder-type scaling has been observed in their eyelashes.

[Diagnosis and treatment of demodectic belpharitis, the first case in Syria]

Demodex is an acarina parasite belongs to family of Tromidiformes, It is worm-like, with a length of 100-400 micron. There are many kind of Demodex affect on animals, and just two types infect humans and they are: Demodex folliculorum and Demodex brives. This mite, living in the hair follicle, in sebaceous gland of human, on the face, nose, neck and lids. Its complete the whole lifecycle, which is approximately 15 days in hair follicle and it spreads via direct contact. Many researches have shown that Demodex is involved in many kinds of dermatitis especially acne rosacea, and a lot of cases have been diagnosed in our country, that were published in scientific journals. Recently, it has been reported that Demodex mites play an active role in the pathogenesis of Blepharitis. It has been suggested that this parasite cause acne, pityriasis folliculorum, papullo-pustular rosacea, granulomatous rosacea, inflammatory papule and folliculitis. This study is about a female case in twenty year old, explained of a huge dropping of her eyelashes, thick squamous in the base of eyelashes and oedema in the edge of the lids. The case was treated with metronidazole ointment and it is recovered within two months

[Demodex blepharitis about two cases]

Demodex is a mite commonly found in eyelash hair follicles and sebaceous glands of healthy people. This mite has been reported in many chronic cases of blepharitis. Two cases of very long term observation and clinical findings of chronic blepharitis caused by demodex folliculorum are presented. A 60 year old woman suffered from recurrent blepharoconjunctivitis during ten years treated locally with antibiotics and steroids. We carried out microbiological test results from the epilated eyelashes. The second case was a 25 year old man who was treated for over five years for blepharitis and repetitive chalazions treated by topically steroids and antibiotics. A significant thickening of the blood vessels in the eyelid and numerous cylindrical cuffs of dry discharge around the base of the eyelashes persuaded us to carry out microbiological tests result from the epilated eyelashes. Demodex folliculorum considered as saprophytic mite may play a pathogenic role in ocular diseases

Phthiriasis palpebrum presenting as chronic atypical unilateral blepharitis

To report a case of phthiriasis palpebrum presenting as unilateral blepharitis in a 4-year-old male child. Materials and Observational case report. A 4-year-old child presented to the emergency room of King Khaled Eye Specialist Hospital complaining of persistent redness after he had trivial trauma to his right eye one day earlier. Live crab lice and their nits were found attached to the eyelashes of the right upper lid. They were removed mechanically by jeweler's forceps under slit lamp and topical anesthesia, and treated with application of erythromycin eye ointment for two weeks. Infestation of the right upper eyelid by phthiriasis palpebrum was diagnosed and treated successfully. Meticulous examination of the eye lids may help early diagnosis and treatment of such communicable diseases. Screening of family members for possible sources of infection, and health education are important issues in the prevention of such diseases

Blefaritis acárica / Blepharitis acarica

En este trabajo se describe el Demodex folliculorum, la blefaritis demodética y se presentan el resultado del estudio de 230 pacientes, analizándose la sintomatología y el tratamiento de los 90 casos encontrados positivos