Resumen ANTECEDENTES: La enfermedad de Paget pigmentada de la mama es una variante poco frecuente de este padecimiento cutáneo, una dermatosis que afecta al complejo areola-pezón de manera típicamente unilateral. La importancia del reconocimiento de esta dermatosis pigmentada inespecífica es que forma parte del diagnóstico diferencial del melanoma cutáneo, por manifestarse como una mácula pigmentada irregular, cuyo estudio histopatológico muestra una proliferación de melanocitos en los estratos suprabasales de la epidermis, fagocitosis de melanina y melanófagos en dermis, hallazgos muy similares al melanoma cutáneo, además de la coexistencia de células claras malignas, características de la enfermedad de Paget. La inmunohistoquímica es una técnica auxiliar en la dermatopatología, que forma parte del proceso diagnóstico de los pacientes para lograr el diagnóstico certero que, al correlacionar la clínica y el estudio histopatológico, le permite al dermatólogo tratar a los pacientes con enfermedad de Paget pigmentada de la mama junto con un equipo multidisciplinario para la búsqueda, diagnóstico y, en su caso, tratamiento quirúrgico de las neoplasias subyacentes que suelen relacionarse con esta variante pigmentada. CASO CLÍNICO: Paciente de 35 años con una lesión pigmentada que afectaba el complejo areola-pezón derecho. Con la correlación histopatológica e inmunohistoquímica se estableció el diagnóstico de enfermedad de Paget pigmentada de la mama y posterior al procedimiento ginecológico, se asoció esta dermatosis con un adenocarcinoma microinvasor triple negativo. CONCLUSIONES: La enfermedad de Paget pigmentada de la mama es un diagnóstico complejo que requiere correlación clínico-patológica y estudios de extensión para valorar su asociación con neoplasias subyacentes.

Abstract BACKGROUND: Pigmented Mammary Paget’s Disease is a rare variant of this skin condition, an unilateral dermatosis that typically affects the areola-nipple complex. The importance of recognizing this nonspecific pigmented dermatosis resides in its differential diagnosis of cutaneous melanoma, as it presents as an irregular pigmented macula. The histopathological study shows proliferation of melanocytes in the suprabasal layers of epidermis, phagocytosis of melanin and melanophages in dermis. These findings are very similar to cutaneous melanoma, in addition to the presence of malignant clear epitelial cells that are characteristic of Paget’s disease. Immunohistochemistry is part of the approach of patients with lesions that shows proliferating melanocytes to rule out other neoplasms. Making an accurate diagnosis by correlating the clinical, histopathological study and immunohistochemistry allows the dermatologist to approach patients with mammary pigmented mammary Paget’s disease with a multidisciplinary team for the diagnosis and surgical treatment of the underlying neoplasms that are usually related to this pigmented variant. CASE REPORT: We report the case of a 35 years old woman with a pigmented lesion that affected the right areola-nipple complex. With the histopathological and immunohistochemical correlation, the diagnosis of pigmented mammary Paget’s disease was made and after the gynecological approach, this dermatosis was associated with a triple negative microinvasive adenocarcinoma. CONCLUSION: Pigmented mammary Paget’s disease is a complicated diagnosis that requires clinicopathological correlation and extension studies to assess its association to underlying neoplasms.

Abstract Introduction: neurofibromatosis is a genetic disorder that affects the growth of neural tissues, with an incidence of 1 in 4 000, with impact on life expectancy due its association with neoplasms and vascular disease. segmental neurofibromatosis is a subtype of neurofibromatosis type 1, with an approximate incidence of 1 in 20 000 to 25 000 people, it is characterized by skin lesions that affects a body segment without crossing midline, they generally have no family history or systemic involvement. Clinical case: a 63-year-old female patient with dermatosis affecting the posterior trunk unilaterally at the level of dermatomes t10-t11, characterized by multiple exophytic, dome-shaped, millimeter sized neoformations, soft in consistency and depressible on palpation. the histopatologic study of one of them confirmed the diagnosis of neurofibroma. the patient did not present neurological or ocular involvement, without affection in relatives. diagnosis of segmental neurofibromatosis was made. Conclusions: segmental neurofibromatosis is a rare pathology, although it is possibly underdiagnosed due its asymptomatic nature, which causes an apparent low incidence. patients may present variable systemic penetrance and a similar risk of neoplasm compared to patients with neurofibromatosis type 1. despite the benign nature reported in the literature, we suggest a multidisciplinary approach to patients.

Resumen Introducción: la neurofibromatosis es un desorden genético, que afecta el crecimiento de tejidos neurales, con una incidencia de 1 en 4 000 personas, con impacto en la esperanza de vida por su asociación con neoplasias y enfermedad vascular. La neurofibromatosis segmentaria es una variante de la neurofibromatosis tipo 1, con una incidencia aproximada de 1 en 20 000 a 25,000 personas, se caracteriza por lesiones cutáneas que afectan un segmento corporal sin cruzar la línea media. Generalmente no tienen historia familiar ni compromiso sistémico. Caso clínico: paciente de sexo femenino de 63 años con dermatosis que afecta el tronco posterior de manera unilateral a nivel de los dermatomas T10-T11, caracterizada por múltiples neoformaciones exofíticas milimétricas en forma de domo, de consistencia blanda y depresibles a la palpación. El estudio histopatológico de una de ellas confirmó el diagnóstico de neurofibroma. La paciente no presentaba afectación neurológica ni ocular, además, sin afección en familiares, por lo que se establece diagnóstico de neurofibromatosis segmentaria. Conclusiones: la neurofibromatosis segmentaria es una patología poco frecuente, Aunque posiblemente sea subdiagnosticada por su carácter asintomático, lo que ocasiona una aparente baja incidencia. Los pacientes que la padecen pueden presentar penetrancia sistémica variable y un riesgo similar de neoplasias al descrito en pacientes con neurofibromatosis tipo 1. Pese al carácter benigno reportado en la literatura sugerimos un abordaje multidisciplinario de los pacientes.

Resumen OBJETIVO: Describir las dermatosis de la región mamaria que para su diagnóstico durante la consulta dermatológica ameritaron estudio histopatológico. MATERIALES Y MÉTODOS: Estudio retrospectivo llevado a cabo con base en los expedientes electrónicos de pacientes atendidas en el servicio de Dermatopatología entre 1992 y 2021. Los términos de búsqueda fueron: “mama”, “seno”, “areola” y “pezón”. RESULTADOS: Se reunieron 171 reportes histopatológicos. El diagnóstico clínico de envío más común en mujeres fue la infiltración cutánea por cáncer de mama y en hombres el pezón supernumerario. Las dermatosis más frecuentes pertenecieron al grupo de tumoraciones benignas (78 de 171), seguidas de las dermatosis inflamatorias no infecciosas (48 de 171), en tercer lugar las neoplasias malignas (39 de 171) y 6 de 171 correspondieron a dermatosis inflamatorias infecciosas. CONCLUSIONES: Las enfermedades cutáneas de la mama tienen diversas manifestaciones clínicas que, en ocasiones, ameritan un estudio histopatológico, sobre todo para un diagnóstico oportuno de neoplasias malignas.

Abstract OBJECTIVE: Describe dermatoses of the mammary region that warranted histopathological diagnosis in dermatologic consults. MATERIALS AND METHODS: The Hospital “Dr. Manuel Gea Gonzalez” Dermatopathology Department record database was reviewed in the 1992 to 2021 period, using the search engine terms “breast,” “mammary,” “nipple,” and “areola.” Lesions were classified as benign, malignant, infectious and noninfectious inflammatory tumors. RESULTS: 171 histopathological reports were reviewed. There was a female predominance in histopathological studies (153/171). The most frequent clinical diagnosis for referral in female patients was breast cancer with cutaneous infiltration; supernumerary nipple was the most frequent clinical diagnosis for male patients. The most frequent dermatoses belonged to the benign tumor category (78/171), followed by noninfectious inflammatory dermatoses (48/171). Malignant neoplasms were in third place (39/171), and 3.5% of dermatoses were infectious inflammatory dermatoses. CONCLUSIONS: Cutaneous mammary disease has diverse clinical presentations that might occasionally warrant histopathological studies, mainly for the early diagnosis of malignant neoplasms.

ABSTRACT Actinic prurigo (AP) is a type of photodermatosis that primarily affects the Latin American mestizo population. Histologically, AP cheilitis exhibits acanthosis with spongiosis and vacuolation of the basal cell layer overlying a dense lymphocytic inflammatory infiltrate that forms well-defined lymphoid follicles. Toluidine blue is a thiazide, acidophilic, and metachromatic dye used in vivo to selectively stain the acidic components of tissues such as sulfates, carboxylates, and phosphate radicals that are incorporated into DNA and RNA. It is necessary to develop a method that allows detecting, on clinical grounds the area of the lesion in which it is more feasible to find such structures. Thus to increase the sensitivity of the biopsy, in AP cheilitis to accurately identify where the lymphoid follicles reside, based on the higher concentration of DNA in such structures and thus confirm the diagnosis. In this study, staining was positive in 85% of patients with AP cheilitis, in 14 of whom 82% lymphoid follicles were observed by histopathology. One of the pathologist’s problems in establishing the diagnosis of AP is that the main histopathological characteristics are not always identified in the submitted samples because it is not easy to clinically identify the most representative site of the lesion selected for performing a biopsy. Based on our results, we propose using toluidine blue as an auxiliary method to choose a tissue sample to facilitate the diagnosis and allow clinicians to make clinical correlations between the histopathological and therapeutic findings.

Abstract Introduction: CD30+ anaplastic large T cell lymphoma is a cutaneous primary lymphoma in which there is no evidence of systemic disease; histopathological study is required for its diagnosis. Objective: To present the cases diagnosed with primary cutaneous CD30+ anaplastic large T-cell lymphoma over a 24-year period in Hospital General “Dr. Manuel Gea González” Department of Dermatology. Method: Retrospective study. Descriptive statistics was carried out. Information was collected on gender, age, clinical characteristics, complementary test results, previous and current treatments, histopathological studies reports and immunohistochemistry test results. Results: Of 29 309 records, nine patients (0.000034%) with a diagnosis of CD30+ anaplastic T cell lymphoma were found. Histopathological and immunohistochemical diagnosis was confirmed by two certified dermatopathologists. Average age was 61.2 years, and there was a predominance of the female gender, with initial clinical presentation as a papular or nodular lesion and varied topography. Conclusions: The prognosis of CD30+ anaplastic large T cell lymphoma in the studied population was dependent on clinical stage. The treatment at early stages has favorable results.

Resumen Introducción: El linfoma anaplásico de células T grandes CD30+ es un linfoma primario cutáneo en el cual no hay evidencia de enfermedad sistémica; para su diagnóstico es necesario el estudio histopatológico. Objetivo: Presentar los casos diagnosticados en el Departamento de Dermatología del Hospital General “Dr. Manuel Gea González” con linfomas anaplásicos de células T grandes primarios cutáneos CD30+ durante un periodo de 24 años. Método: Estudio retrospectivo en el que realizó estadística descriptiva. Se recopiló información de sexo, edad, características clínicas, resultados de pruebas complementarias, tratamientos previos y actuales, reportes de los estudios histopatológicos y de inmunohistoquímica. Resultados: Entre 29 309 expedientes, se encontraron nueve casos (0.000034 %) con diagnóstico de linfoma anaplásico de células T CD30+. Se hizo la confirmación del diagnóstico histopatológico e inmunohistoquímico por dos dermatopatólogos certificados. La edad promedio fue de 61.2 años, hubo predominio del sexo femenino y de lesión papular o nodular y topografía variada como presentación clínica inicial. Conclusiones: El pronóstico del linfoma anaplásico de células T grandes CD30+ en la población estudiada fue dependiente del estadio clínico. El tratamiento en etapas tempranas tiene resultados favorables.

ABSTRACT Myiasis caused by Dermatobia hominis , the human botfly, is frequent in the Americas, however, scarce morphological and molecular information exist regarding this dipteran. We describe three cases in urban areas of Mexico were D. hominis is not endemic. Morphological and genetic identification were performed using the cytochrome oxidase I as a molecular marker. The mitochondrial cytochrome oxidase I gene is useful for inferring the genetic divergence of D. hominis .

Abstract: Fox-Fordyce disease is a relatively infrequent pathology of the apocrine glands that affects almost exclusively young women. The disease is characterized by the presence of pruritic follicular papules mainly in the armpits that respond poorly to treatment and severely affect the patient’s quality of life. We report two cases with clinical diagnosis and histopathological confirmation, presenting perifollicular xanthomatosis on histological examination, recently described as a distinctive, consistent, and specific feature of this disease.

Abstract Background Malassezia folliculitis (FM) is an infection of the hair follicle caused mainly by M. furfur. It affects adolescents and adults, it is characterized by itchy papulopustular follicular skin lesions affecting the trunk. Objective To describe the clinical and epidemiological characteristics of patients of the Dermatologic Center of Yucatan (CDY), which diagnosis of FM was made by direct microscopy (EMD). Methods A Cross-sectional, descriptive and retrospective study was performed between January 2009 and December 2015. EMDs records of the Laboratory of Micology of CDY were reviewed. Results and conclusions We identified 56 cases, the 78.6% were males, trunk was the most frequent topography (94.6%), followed by face (16.1%), neck (12.5%), upper limbs (10.7%) and lower limbs (3.6%). Twenty-two cases (39.3%) were observed in 2015, and 86.3% of these cases were observed between June and September. Six cases (27.7%) had a history of having used topical steroids and 3 cases (13.6%) of systemic antibiotics. All cases were diagnosed by EMD with methylene blue, a fast and non-invasive technique that allows early treatment.

Resumen Antecedentes La foliculitis por Malassezia spp. (FM) es una infección del folículo piloso causada principalmente por M. furfur. Afecta a adolescentes y adultos y se caracteriza por la presencia de pápulas y pústulas foliculares pruriginosas localizadas en el tronco. Objetivo Describir las características epidemiológicas y clínicas de los pacientes con FM diagnosticados por examen directo (EMD) en el Centro Dermatológico de Yucatán (CDY). Métodos Se realizó un estudio transversal, descriptivo y retrospectivo en el que se revisaron los registros de los EMDs realizados en el Laboratorio de Micología del CDY durante enero 2009 - diciembre 2015. Resultados y conclusiones Se documentaron 56 casos, el 78.6% fueron hombres. La edad promedio fue de 21.4 años. La topografía más frecuente fue el tronco (94.6%), seguido de cara (16.1%), cuello (12.5%), extremidades superiores (10.7%) e inferiores (3.6%). Durante el 2015 se documentaron 22 casos (39.3%) de los cuales el 86.3% se presentaron en junio-septiembre. Seis casos (27.7%) utilizaron previamente esteroides tópicos y 3 casos (13.6%) antibióticos sistémicos. Todos los casos fueron diagnosticados mediante EMD con azul de metileno, el cual es una técnica rápida y no invasiva que permite iniciar un tratamiento temprano.

Abstract BACKGROUND: Comedonic nevus is a rare benign tumor of the pilo-sebaceous unit which can occur in unusual topography such as the mammary region. It can have an isolated presentation or as part of the nevus comedonic syndrome. There is no treat-ment except for aesthetic reasons or secondary complications. CLINICAL CASE: A 45- year-old patient presented with a unilateral, linearly arranged dermatosis located on the trunk, affecting the axillary midline and the right mam-mary region. Characterized by a plaque of 4 x 1 cm, formed by open comedons. Starts from childhood and referred as asymptomatic, it has not presented changes during life. By dermoscopy 3mm diameter black keratin plugs were observed. An incisional biopsy was performed and sent to a histopathological study, which reported as comedonic nevus. CONCLUSION: Comedonic nevus is a rare tumor that can occur in the mammary region and must be recognized as a benign entity.

Resumen ANTECEDENTES: El nevo comedónico es un tumor benigno del aparato pilosebáceo. Puede aparecer en topografía poco habitual, como la región mamaria. Es de manifes-tación aislada o puede formar parte del síndrome de nevo comedónico. No precisa tratamiento, salvo por motivos estéticos o complicaciones. CASO CLINICO: Paciente de 45 años que acudió a consulta por una dermatosis locali-zada en el tronco, unilateral, dispuesta linealmente, que afectaba la línea axilar media y la región mamaria derecha. Caracterizada por una placa de 4 x 1 cm, conformada por comedones abiertos. El padecimiento se inició durante la infancia, asintomático, sin aumento de la dermatosis. En la dermoscopia se observaron tapones de queratina color negro de 3 mm de diámetro. La biopsia incisional reportó que se trataba de un nevo comedónico. CONCLUSION: El nevo comedónico es un tumor poco frecuente que puede aparecer en la región mamaria y debe reconocerse como padecimiento benigno.

Abstract Tuberculosis has been overtime public health problem. The World Health Organization reports annually about 8 million new cases and 3 million deaths. In Mexico, an estimation of around 64,000 prevalent cases of this disease are reported annually. Tuberculosis can affect different organs with clinica presentations that mimic other diseases. A patient presents a history of normal pregnancy and vaginal delivery without complications for 4 months. The clinical picture begins in the postpartum period with the presence of cough accesses registered a month later accompanied by fatigue, weight loss, diffuse abdominal pain, diarrhea and fever syndrome. She received multiple treatments without improvement. She was ad missioned to our hospital and an acute abdomen laparotomy was performed with findings of abdominal frozen thickened parietal peritoneum, fixed adhesions, collections of pelvic cavity with whitish, slightly fetid pus, friable tissue, presence of granulomas in bowel loop. A subtotal abdominal hysterectomy with bilateral oophorectomy was performed. The postoperative evolution showed a slow improvement after the reportand was corroborated bya histopathological diagnosis of pelvic tuberculosis culture and the initiation of a specific treatment.

Resumen A lo largo del tiempo, la tuberculosis ha sido un problema de salud pública. La Organización Mundial de la Salud reporta anualmente alrededor de 8 millones de casos nuevos y 3 millones de muertes. En México se estima que anualmente prevalecen cerca de 64,000 casos de esta enfermedad gue puede afectar diferentes órganos con presentaciones clínicas gue simulan otras patologías. Se presenta el caso de una paciente de 22 años de edad con antecedente de embarazo normo evolutivo y parto vaginal 4 meses antes sin complicaciones, gue inició su cuadro clínico en el puerperio con presencia de tos en accesos gue remitió un mes posterior acompañado de síndrome de desgaste, pérdida de peso, dolor abdominal difuso, diarrea y fiebre. Recibió múltiples tratamientos sin mejoría, ingresó a nuestro hospita con cuadro de síndrome abdominal agudo y se le realizó laparotomía exploradora con hallazgos de abdomen congelado, engrosamiento de peritoneo parietal, adherencias fijas, colecciones en hueco pélvico, con material purulento caseoso, blanquecino, poco fétido, tejido friable, presencia de granulomas en asas de intestino; se realizó histerectomía subtotal abdominal con ooforectomía bilateral, la evolución posquirúrgica fue lenta hacia la mejoría tras corroborar por reporte histopatológico y cultivo el diagnóstico de tuberculosis pélvica e iniciar tratamiento específico.

Abstract BACKGROUND: Actinic prurigo is an idiopathic photodermatosis, the pathophysiology of which has been hypothesized to involve subtype IV type b (Th2) hypersensitive response, whereby IL4, IL5, and IL13 are secreted and mediate the production of B cells, IgE, and IgG4. OBJECTIVES: To examine the association of serum IgE levels and the clinical severity of injuries. METHODS: This case-control study comprised patients with a clinical and histopathological diagnosis of actinic prurigo, as well as clinically healthy subjects, from whom 3cc of peripheral blood was taken for immunoassay. Cases were classified by lesion severity as mild, moderate, and severe. Descriptive statistics were analyzed, and chi-square test was performed. RESULTS: We included 21 actinic prurigo patients and 21 subjects without disease; 11 patients with actinic prurigo had elevated serum IgE levels, and 10 had low serum levels. Six actinic prurigo (AP) patients with elevated serum levels of IgE had moderate injuries, 4 had severe injuries, and 1 had minor injuries. Eight out of 10 patients with normal IgE levels presented with minor injuries in the clinical evaluation. The 21 controls did not have increased serum IgE levels. CONCLUSIONS: Elevated IgE levels are associated with moderate to severe clinical lesions, suggesting that actinic prurigo entails a type IV subtype b hypersensitivity response in which Th2 cells predominate.

The myofibroma is defined as a benign neoplasm formed by myoid contractile cells localized around the wall of thin blood vessels, it is a tumor that presents itself mostly in infancy although it may occur at any age and it is most common in head and neck; it is uncommon to be localized in the oral cavity and even less common if it is intraosseous. It may also be associated to miofibromatosis or present itself as a solitary lesion. The differential diagnosis depends on the localization and the radiographic characteristics; it would be very difficult to include, at first hand, myofibroma as an intraosseous lesion. Histopathologically, a neoplasm with a biphasic pattern formed by spindle cells in fascicles and bundles, spindle nucleus with eosinophilic cytoplasm inside a hyalinized stroma was found. In lesions of neoplasms of spindle cells histological studies should be supported by an immunohistochemical panel and show positive results to antibodies Actin, smooth muscle Actin and Vimentin.

El miofibroma es una neoplasia benigna compuesta por células mioides contráctiles localizadas alrededor de la pared de vasos sanguíneos delgados, es un tumor que se presenta sobre todo en la infancia aunque puede ocurrir a cualquier edad, tiene predilección en cabeza y cuello, sin embargo en cavidad oral es raro y aún más si es intraóseo, puede estar asociado a miofibromatosis o bien presentarse de manera solitaria. Los diagnósticos diferenciales dependen de la localización y de las características radiográficas y de primera instancia es muy difícil incluir al miofibroma entre las lesiones intraóseas. Histológicamente presenta patrón bifásico conformado por células fusiformes dispuestas en fascículos y haces así como núcleos fusiformes con citoplasma eosinófilo dentro de un estroma hialinizado. Es necesario recurrir al panel de inmunohistoquímica en neoplasias de células fusiformes, positivo a Acs Actina, Actina músculo liso y Vimentina. Reportamos el caso de una mujer de 45 año con un miofibroma en la mandíbula.

Background. Hyperimmunoglobulin E syndrome is a rare systemic immunodeficiency characterized by eczematous dermatitis, recurrent cold abscesses, lung infections with pneumatoceles, coarse facial appearance, high IgE levels and eosinophilia. Case reports. Case 1: We report the case of an 11-year-old female with a history of recurrent lung infections, recurrent gastroenteritis, eczematous dermatitis affecting the skin folds and cold abscesses. Laboratory studies showed elevated eosinophils (16 070) and IgE 4864 IU. The patient received treatment with g-globulin, showing adequate clinic response to treatment. Case 2: We present the case of a 12-year-old female with a history of recurrent otitis and suppurative conjunctivitis, showing widespread and chronic infected eczema. Laboratory studies showed elevated IgE (3 000 IU). She was treated with dapsone, trimethoprim/sulfamethoxazole and methotrexate. Conclusions. We presented two patients with eczematous skin, recurrent infections and increased IgE levels, which are compatible with hyperimmunoglobulin E autosomal recessive syndrome.

Introducción. El síndrome de hiperinmunoglobulinemia E es una inmunodeficiencia sistémica poco frecuente, caracterizada por dermatitis eccematosa, abscesos fríos recurrentes, infecciones pulmonares con formación de neumatoceles, facies tosca, niveles elevados de inmunoglobulina E (IgE) en suero y eosinofilia. Casos clínicos. Caso 1. Femenino de 11 años de edad con antecedentes de neumonía recurrente, gastroenteritis de repetición, dermatitis eccematosa de predominio en pliegues, y abscesos fríos; en estudios de laboratorio destacó el hallazgo de 16 070 eosinófilos e IgE de 4 864 Ul. Manejada con gammaglobulina se observó buena respuesta clínica. Caso 2. Femenino de 12 años de edad con historia de otitis recurrente y conjuntivitis supurativa, presentaba eccema crónico generalizado e impetiginizado. En estudios de laboratorio se reportó IgE de 3 000 UI; fue manejada con dapsona, trimetropim/sulfametoxazol y metotrexate. Conclusión. Los 2 casos aquí informados presentaron piel eccematosa, infecciones recurrentes e incremento de los niveles de IgE, compatibles con síndrome de hiperinmunoglobulinemia E en la forma autosómica recesiva.

Introduction: The etiology of lichen planus (LP) is unknown. The possible role of hepatitis C virus (HCV) has been studied with controversial results. Materials and Methods: The aim of this study was to determine the prevalence of HCV infection in 36 patients with lichen planus (LP) confirmed by histopathology, 12 in a retrospective way, and 24 in a prospective one. The controls were 60 consecutive blood donors from the Blood Bank of the hospital. Third generation enzyme immunoassay screening test was employed for determination of antibodies against HCV. Results: A prevalence of HCV infection of 2.77% in LP patients, and 0% in control group (Fisher's exact test -p=0.375). Conclusions: We found in our patients with LP a lower prevalence of positive serology for HCV than that reported in the literature. Since all studies have found patients with LP without infection by HC V, we think that other factors in the pathogenesis of this dermatosis need to be studied.

Antecedentes: la causa de liquen plano (LP) es desconocida. Se ha estudiado el posible papel del virus de hepatitis C (VHC) con resultados controvertidos. Material y métodos: el objetivo de este estudio fue determinar la prevalencia de infección por virus de hepatitis C en 36 pacientes con LP confirmado por histopatología, 12 en forma retrospectiva, y 24 en forma prospectiva. El grupo control constó de 60 donadores de sangre consecutivos del Banco de sangre del hospital. La prueba de inmunoensayo ligado a enzima de tercera generación fue utilizada para la determinación de anticuerpos contra VHC. Resultados:una prevalencia de infección por VHC de 2.77% en pacientes con LP, y 0% en el grupo control (Prueba exacta de Fisher - p=0.375). Conclusiones: en nuestro grupo de pacientes con LP se encontró prevalencia de serología positiva para VHC menor a la reportada en la literatura. Como en todos los estudios se han encontrado pacientes con LP sin infección por VHC, consideramos que existen otros factores en la patogénesis de esta dermatosis que deben ser estudiados.