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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.

Introduction: Spitz nevus is an uncommon, benign melanocytic proliferation that primarily appears on face, trunk or lower extremities of children. This lesion may share clinical and microscopical characteristics with melanoma, making it a diagnostic and management challenge. Case Report: A 13-year old male presented with an asymptomatic chronic dermatosis located on the third left-hand nail. Cutaneous examination revealed a homogeneous dark brown melanonychia which extended up to the cuticle. Upon dermoscopy, longitudinal bands measuring less than 3 mm wide of heterogeneous colors ranging from light to dark brown, and positive Hutchinson’s sign were observed. Discussion/Conclusion: We report the second case of a Spitz nevus ungually localized which strongly resembled an ungual melanoma with a positive Hutchinson’s sign upon dermoscopy. Describing the infrequent presentation and location of the Spitz nevus poses an opportunity to establish diagnostic and management criteria in the near future.

Pyoderma gangrenosum is a rare, neutrophil-mediated, auto-inflammatory dermatosis that wound care specialists must be prepared to recognise. This condition has clinical features analogous to infectious processes. There is no specific diagnostic test and the diagnosis is usually obtained from exclusion. Its early recognition and proper management with prompt initiation of immunosuppressive therapy are essential to improve the quality of life and the prognosis of patients.

Purpose of review. Inflammatory tinea is an uncommon group of dermatophyte entities that predominantly cause fungal infection of the skin and hair. This review intends to present all of the available evidence regarding its epidemiology, etiopathogenesis, clinical features, and diagnostic methods as well as treatments recommended for various inflammatory tinea infections. This article provides a review of Majocchi’s granuloma and dermatophytic or Hadida’s disease. Recent findings. The new phylogenetic classification of dermatophytes includes nine genera, and those that affect humans are Trichophyton, Microsporum, Epidermophyton, and Nannizzia. Furthermore, molecular advancements have revealed impaired antifungal immune responses caused by inflammatory tinea, which are detailed in this article. Summary. The common denominator in these pathologies is the presence of impaired immune responses and, consequently, an impaired inflammatory response by the host. It is necessary to be familiar with these immunological characteristics in order to use the appropriate diagnostic methods and to provide adequate treatment.

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive malignancy of the skin and hematopoietic system. There are few pediatric cases reported in the literature. Management of primary cutaneous BPDCN is challenging because, despite an apparently indolent clinical presentation, rapid dissemination with high mortality can occur. We describe a child with isolated cutaneous involvement who had a good response to chemotherapy as first-line treatment of BPDCN.

Pityriasis versicolor (PV) is a superficial mycosis that it can occur at any age, even in newborns. In this review, we will describe epidemiological data, mycological characteristics of yeast, pathogenesis and clinical characteristics of the disease, different diagnostic resources, and the current recommendations for treatment. The typical morphology and topography of PV allow us to make a quick diagnosis, but atypical presentations have been described. Diagnostic tools, such as dermoscopy, can also reveal patterns that allow the evaluation of characteristics of scales and pigment in lesions. The discovery of new species and new mechanisms of interaction with the host has broadened the panorama of aetiological possibilities. Although PV is a common disorder, extensive research is necessary to better understand the pathophysiology of the disease, immunological characteristics of the pathogen-host relationship and resources needed to precisely diagnose the disease, treat the disease, and avoid its chronic and recurrent course.

We present the case of an HIV-positive patient who developed polymorphous lesions in which the evidence in the skin biopsy corresponds to the diagnosis of bacillary angiomatosis, and further tests proved the pathological agent involved in this case is not the usual Bartonella species, B. henselae and B. quintana, but B. elizabethae. As far as we know, this is the first case of bacillary angiomatosis secondary to this etiological agent.

INTRODUCCIÓN: El lupus eritematoso (LE) es una enfermedad autoinmune poco frecuente en el sexo masculino, que presenta manifestaciones clínicas múltiples relacionadas al pronóstico de la enfermedad. La etiología es desconocida, sin embargo, se relaciona a la exposición de radiación ultravioleta y alteración en la función linfocítica. El lupus eritematoso profundo (LEP) es una variante clínica de LE cutáneo que se presenta entre el 1% al 3% de los pacientes y únicamente el 10% de los casos reportados en la literatura pertenecen al sexo masculino. Hasta el 50% de los pacientes con LEP presentan progresión a lupus eritematoso sistémico (LES) durante su evolución.PRESENTACIÓN DEL CASO: Adolescente 16 años, previamente sano, que presentó una placa eritematosas, induradas y asintomáticas en mejilla izquierda de evolución crónica. Se realizó biopsia incisional con diagnóstico de LEP. El resto del abordaje para descartar lupus eritematoso sistémico resultó negativo. El paciente recibió tratamiento con corticosteroide tópico por 4 semanas en esquema de reducción así como fotoprotección estricta con mejoría del eritema y disminución del área indurada. Actualmente el paciente continúa en seguimiento con atención a signos y síntomas sugerentes de lupus eritematoso sistémico.CONCLUSIÓN: El LEP es una dermatosis multifactorial poco frecuente en el sexo masculino, por lo que la literatura actual podría no ser representativa en este sexo. Es necesario realizar un abordaje amplio al momento del diagnóstico con pruebas de laboratorio séricas y reumatológicas. Es de suma importancia ser capaces de identificar de manera temprana signos y síntomas que sugieran progresión a LES o linfoma.

The onycholemmal horn is an exceedingly rare subungual tumor characterized by trichilemmal-like keratinization pattern. The only previous instance of onycholemmal horn dates back to 1983 when Haneke reported a keratotic subungual tumor clinically and histologically comparable to a trichilemmal horn. No other case of this condition has been reported so far. We present the case of a 72-year-old female patient, with a history of a slowly growing tumor originating from the nail bed epithelium of the left thumb. The lesion was surgically removed, and pathological examination was consistent with the diagnosis of an onycholemmal horn. Additionally, this study aims to elucidate the correlation between the onycholemmal and trichilemmal keratinization.

We present the case of a male infant diagnosed with IPEX (immune dysregulation, polyendocrinopathy, enteropathy, and X-linked) syndrome who presented a generalized rash with a BCG site reaction several months after vaccination. Erythema and induration at BCG site might be due to BCG which is a known complication of inborn errors of immunity with susceptibility to mycobacterial infection. However, in our patient this dermatological manifestation might be secondary to immune dysregulation, given the important role of Tregs and Th17 cells in mycobacterial immunity, similar to that observed in Kawasaki disease patients.

Introduction Hypohidrotic ectodermal dysplasia (HED) is a genetic condition typified by alterations in skin structures including sweat glands, hair, nails, and teeth. Hair findings in HED have been poorly characterized in larger series. Objective To characterize scalp and hair findings of patients with HED clinically and with trichoscopy and light microscopy. Methods A cross-sectional study in 21 pediatric HED patients was performed using available clinical and scalp dermatoscopic images, as well as pulled-hair samples for clinical evaluation, trichoscopic, and light microscopic analyses. Results Seventeen out of 21 patients (81%) were men. Twenty patients had straight hair. Sixteen patients had decreased hair density, 6 of whom had hair loss mainly in the temporal and occipital regions. Fourteen patients had hair whorls. On trichoscopy, we observed: single-hair follicular units (n = 19, 90%), scalp hyperpigmentation (n = 13, 62%), variable diameter of the hair shafts (n = 12, 57%), perifollicular scales (n = 8, 38%), scalp erythema (n = 8, 38%), and short curly pigtail hairs (n = 6, 29%). On light microscopy, findings included: hair shafts with irregular diameter (n = 7, 33%), heterogeneous hair color (n = 6, 29%), trichoptilosis (n = 2, 10%), and pili torti (n = 1, 5%). Conclusions In this series, hair findings in HED were similar to those described in previous studies. However, we describe two new clinical and two trichoscopic findings: decreased hair density mainly in the temporal and occipital regions, oblique upwards occipital hair follicles orientation, angled hairs, and short curly pigtail hairs. These heterogeneous findings may reflect the multiple factors and signaling pathways that can be affected in these syndromes.

Introduction: Onychomycosis is a frequent chronic nail infection, with a worldwide prevalence of 5.5% making it the most common nail disease, and its incidence increases with age. Clinically, it causes discoloration and thickening of the nail plate and may be accompanied by onycholysis. However, little is known of the subclinical infection. Methods: We studied adult male and female outpatients auto-referred as healthy and that had healthy appearing toenails. Nail distal clippings were obtained from the right first toenail. This sample was stained with PAS and observed by an expert dermatopathologist searching for fungal structures. Results: A total of 32 samples were included: 8 from men (25%) and 24 from women (75%), with ages ranging from 27 to 66 years (mean age of 43 years). Twenty-four patients did not present any histopathological finding suggestive of infection (75%), while 7 patients had a single finding (spores or hyphae) (21.8%), and 1 patient had both findings (3.12%). Discussion/Conclusion: We found 4 patients with yeasts, 3 with hyphae, and 1 patient with a combined infection with both yeasts and hyphae (3.1%). These add up to 25% of the clinically apparent healthy nails. Our results show that we still have much to learn from the initial stages of onychomycosis and that our population probably has higher incidence of this nail disease, so we must be alert to subtle nail changes. As our participants signed an informed consent, we will contact those that resulted positive for follow up consultations.

Griscelli syndrome type 2 (GS2) features silvery-grey hair, bronzed skin and immunodeficiency.1 The only curative treatment for GS2 is haematopoietic stem cell transplantation (HSCT) which corrects the immune and haematologic defects with persistence of oculocutaneous abnormalities.

Atopic dermatitis (AD) is a common chronic, inherited, relapsing, inflammatory skin condition. A multifactorial etiology has been postulated, including genetic and immunological factors, impaired skin barrier function and environmental triggers, all of them are relevant in the pathogenesis. Malassezia spp. is the most common fungi of the skin microbiome. Most of the studies comparing the skin colonization with Malassezia spp. in healthy people and AD patients did not show difference between both groups. This review aims to show the studies carried out in this regard and the reported evidence about the role of Malassezia spp. in the pathogenesis of AD. The rate of IgE-mediated sensitization Malassezia spp. is very high in AD patients, mainly in adult patients and in patients with involvement in the head and neck. Different mechanisms have been postulated to explain the interaction of Malassezia spp. with human skin cells and immune cells and how its interaction contributes to the inflammation process in AD. Systemic and topical azole antifungals have been used with doubtful results showing beneficial effects in some AD patients. There is no clear explanation for the high frequency of Malassezia spp. sensitization in AD patients in relation with healthy individuals. Further research is necessary to determine the specific role of Malassezia in AD and the indication for the use of antifungals in this disease.

Dermatobia hominis is a fly endemic to and widely distributed throughout the Americas; it is found from the southern regions of Mexico to Argentina. However, because of widespread travel, myiasis has become common in countries where neither the disease nor the species that cause this infection are endemic. Central Mexico, for instance, is not a region where myiasis is endemic. We, thus, describe three cases of D. hominis myiasis: two autochthonous cases from the southern part of Mexico and one imported from Costa Rica. In addition, morphological and genetic identification was performed on the maggots extracted from the patients.

Resumen Antecedentes El carcinoma de piel no melanoma basocelular y el carcinoma epidermoide o espinocelular (CEC) son tumores frecuentes. El carcinoma basocelular es el cancer mas frecuente y el menos agresivo; en algunas ocasiones, a pesar del tratamiento quirurgico con margenes amplios, un porcentaje bajo tiene comportamiento agresivo, como invasion local extensa, recurrencias y metastasis. El CEC tiene un comportamiento mas agresivo, primero en piel, despues en ganglios linfaticos y, raramente, con metastasis a otros organos. Objetivo Identificar las caracteristicas de los CEC recurrentes y la frecuencia de aparicion de nuevos tumores, tras el tratamiento quirurgico con cirugia convencional y cierre diferido de herida hasta obtener el resultado histologico libre de tumor (transoperatorio tardio), esto con la finalidad de tener mejores opciones de tratamiento en la poblacion mexicana. Material y metodo Se revisaron los expedientes de 10 anos y se incluyeron aquellos que tenian diagnostico de CEC. Resultados Se incluyeron 114 tumores en 103 pacientes. Utilizando un analisis descriptivo, se encontro que la media de diagnostico de casos nuevos por ano fue 32.2. Pacientes masculinos 48 (46.6%) y 55 (53.4%) femeninos. La edad diagnostica fue entre 19 y 91 anos (media = 71.94; DE = 13.34) con un tiempo de evolucion de 1 a 112 meses (media = 12 meses; DE = 2.65). El mas frecuente es en la mejilla y la variedad histologica invasiva se da en el 54%. En 14 pacientes se encontro un segundo CEC. Solo tuvimos 4 recurrencias, que aparecieron entre el primer y el cuarto ano de seguimiento, y 3 de estos fueron tratados con cirugia con transoperatorio tardio. Conclusion Este estudio demostro que la tecnica de cirugia con transoperatorio tardio es adaptable para el tratamiento de CEC con buenos resultados y bajo porcentaje de recurrencia en un seguimiento a 10 anos.

Introduction Craniosynostosis and clavicular hypoplasia, delayed closure of the fontanelle, cranial defects, anal and genitourinary abnormalities, and skin (CDAGS), is an infrequent autosomal recessive entity with only 10 cases reported; no associated gene has been identified so far. Case Report The proband is a 2-year-old Mexican female with brachycephaly, cleft palate, anal malformation with rectovestibular fistula, and clinodactyly of the third toe overlapping the second. At 4 months of age, she developed a disseminated dermatosis with erythematous scaly nummular plaques, elevated keratotic sharp borders with thin to broad flaking, hematic crusts, and keratotic surface in others. The lesions were slightly pruritic and began at the lower limbs with posterior dissemination to the upper limbs, head, and trunk; palms and soles were unaffected. A skin biopsy showed hyperkeratosis, parakeratosis, acanthosis, and perivascular inflammatory infiltration in the upper reticular dermis among other alterations. She also presented mild bilateral neurosensory hypoacusia and enamel dysplasia. Her karyotype was normal. Treatment with topical hydrating creams partially improved the skin lesions at their center, while the sharply keratotic borders remained, giving a clinical resemblance to porokeratosis. Discussion The patient suffers from CDAGS syndrome but has normal development, and feet abnormality was described in only one other patient. The treatment with topical hydrating creams improved the skin lesions at their center, while porokeratotic characteristics persisted. CDAGS remains a diagnostic challenge; a comparison with previously reported cases is discussed. The timely detection of the syndrome will allow early treatment that may improve the condition of the patients.

An accessory tragus (AT) is a congenital flesh-colored nodule occasionally covered with vellus hair. It can arise anywhere along the line from the preauricular area to the corner of the mouth. It can also be found on the glabella or suprasternal region. The tragus is derived from the first branchial arch, which also develops into the mandible and mouth. The rest of the external ear develops from the second branchial arch. AT may occur as an isolated defect or in chromosomal first branchial arch syndromes with ear anomalies, cleft lip and palate, and mandibular hypoplasia.

Resumen Las mascotas exóticas, como el erizo de tierra, son capaces de transmitir al ser humano diferentes infecciones, como salmonelosis, micobacterias, protozoos como Cryptosporidium parvum, y dermatofitosis. Presentamos el caso de un paciente adulto masculino, que recientemente había adquirido un erizo de tierra, que presentó en la mano una lesión de tiña incógnita y un granuloma de Majocchi. Se identificó el agente etiológico como Trichophyton erinacei, por cultivo micológico y biología molecular. El paciente se trató con terbinafina por vía oral, por seis meses, con excelente respuesta.

Foreign modelling agent reactions (FMAR) are the result of the injection of unapproved high-viscosity fluids with the purpose of cosmetic body modelling. Its consequences lead to ulceration, disfigurement and even death, and it has reached epidemic proportions in several regions of the world. We describe a series of patients treated for FMARs in a specialised wound care centre and a thorough review of the literature. A retrospective chart review was performed from January 1999 to September 2015 of patients who had been injected with non-medical foreign agents and who developed cutaneous ulceration needing treatment at the dermatology wound care centre. This study involved 23 patients whose ages ranged from 22 to 67 years with higher proportion of women and homosexual men. The most commonly injected sites were the buttocks (38·5%), legs (18%), thighs (15·4%) and breasts (11·8%). Mineral oil (39%) and other unknown substances (30·4%) were the most commonly injected. The latency period ranged from 1 week to 17 years. Complications included several skin changes such as sclerosis and ulceration as well as systemic complications. FMAR is a severe syndrome that may lead to deadly complications, and is still very common in Latin America.

Actinic prurigo (AP) is an idiopathic photodermatosis; the initial manifestations usually occur during the first decades of life but can appear at any age. Cases are usually diagnosed late once the lesions have exacerbated; due to the extensive involvement of the vermilion border and the etiology, it has been confused with and related to a potentially malignant process. Syndecan-1 and E-cadherin were positive in the epidermis, with moderate-to-intense staining in 100% of samples. Ki67 and MCM3 were expressed in the lower third of the epidermis and showed greater immunolabeling in samples that contained lymphoid follicles (Ki 67: epidermis [17.7% ± 6.79%] and dermis [7.73% ± 6.69%]; MCM3: epidermis [22.92% ± 10.12%] and dermis [6.13% ± 6.27%]). In conclusion AP is a disease in which there is no evidence that the lesions are potentially cancerous. AP cheilitis should not be confused with actinic cheilitis because they are separate entities.

espanolIntroduccion: El linfoma anaplasico de celulas T grandes CD30+ es un linfoma primario cutaneo en el cual no hay evidencia de enfermedad sistemica; para su diagnostico es necesario el estudio histopatologico. Objetivo: Presentar los casos diagnosticados en el Departamento de Dermatologia del Hospital General “Dr. Manuel Gea Gonzalez” con linfomas anaplasicos de celulas T grandes primarios cutaneos CD30+ durante un periodo de 24 anos. Metodo: Estudio retrospectivo en el que realizo estadistica descriptiva. Se recopilo informacion de sexo, edad, caracteristicas clinicas, resultados de pruebas complementarias, tratamientos previos y actuales, reportes de los estudios histopatologicos y de inmunohistoquimica. Resultados: Entre 29 309 expedientes, se encontraron nueve casos (0.000034 %) con diagnostico de linfoma anaplasico de celulas T CD30+. Se hizo la confirmacion del diagnostico histopatologico e inmunohistoquimico por dos dermatopatologos certificados. La edad promedio fue de 61.2 anos, hubo predominio del sexo femenino y de lesion papular o nodular y topografia variada como presentacion clinica inicial. Conclusiones: El pronostico del linfoma anaplasico de celulas T grandes CD30+ en la poblacion estudiada fue dependiente del estadio clinico. El tratamiento en etapas tempranas tiene resultados favorables. EnglishIntroduction: 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 Gonzalez” 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.

espanolIntroduccion: Las discrasias linfoides epiteliotropicas de celulas T son un grupo de dermatosis inflamatorias poco frecuentes que pueden progresar a linfomas cutaneos. El tratamiento con radiacion ultravioleta ha sido descrito como seguro y eficaz. Objetivo: Describir la respuesta al tratamiento, sus efectos secundarios y complicaciones. Metodo: Se administro radiacion ultravioleta A con psoralenos (PUVA) a dos pacientes y radiacion ultravioleta B de banda estrecha (NB-UVB) a nueve pacien- tes, con diferentes discrasias. Resultados: Conformaron la serie siete mujeres y cuatro hombres, con edades de 5 a 30 anos y con fototipos III y IV, con diagnostico de discrasia linfoide epiteliotropica hipopigmentada, pitiriasis liquenoide cronica, pa- rapsoriasis hipopigmentada y purpura pigmentada. Dos recibieron PUVA y nueve recibieron NB-UVB. Ocho alcanzaron res- puesta completa y tres respuesta parcial con 10 a 119 sesiones de tratamiento. Ningun paciente presento reactivacion de la enfermedad despues de 34 a 247 sesiones, y ninguno en tratamiento o seguimiento evoluciono a linfoma cutaneo. Los efectos secundarios fueron xerosis y prurito. Conclusion: El tratamiento de las discrasias linfoides con radiacion ultravioleta es eficaz y seguro, con efectos secundarios leves y con respuestas exitosas en la mayoria de los pacientes, en tiempo y numero de sesiones variables. EnglishIntroduction: T-cell lymphoid dyscrasia is a group of different, infrequent, epitheliotropic inflammatory dermatosis that prece- de cutaneous T-cell lymphomas. Treatment with ultraviolet radiation is safe and efficacious. Objective: To describe responses to treatment, secondary effects and complications. Method: Eleven patients with different T-cell lymphoid dyscrasias were treated. Two received psoralens plus ultraviolet A radiation (PUVA) and nine narrow band ultraviolet B radiation (NB-UVB). Results: Seven women and four men from 5 to 30 years-old and phototypes III and IV were included. They had hypopigmen- ted epitheliotropic lymphoid dyscrasia, chronic pityriasis lichenoides, hypopigmented parapsoriasis and pigmented purpuric dermatoses. Two received PUVA and 9 NB-UVB. Eight achieved complete response and three partial response with 10 to 119 sessions. Any patient presented neither relapse nor progression to cutaneous T-cell lymphoma during treatment or in the follow up period after 34 to 247 sessions. Secondary effects were xerosis and mild pruritus. Conclusions: The majority of patients with T-cell lymphoid dyscrasias can be successfully and safely treated with minimal secondary effects after a variable number of sessions and periods of time with ultraviolet radiation.

Background Hypopigmented dermatoses, more evident in dark-skinned people, are a frequent cause of consultation. Their etiology includes a wide range of dermatoses, from benign to malignant diseases. The clinical presentation appears very similar between them, making the correct diagnoses and management a challenge. Methodology Clinical records and histopathological biopsies were identified and compared in patients of the "Dr. Manuel Gea Gonzalez" General Hospital throughout a 16-year period with the presumptive diagnosis of hypopigmented epitheliotropic T-cell dyscrasia (HTCD) or hypopigmented mycosis fungoides (HMF). Immunostaining analysis was performed in each specimen, the panel of antibodies used was: CD3, CD4, CD7, CD8, CD20, and CD62L. Results Thirty cases of 81 patients found in the registries were included in this study. The main age group was formed by children younger than 15 years old. The main clinical differences between both entities were gender, presence of plaques, and neck lesions. The most significant histopathological parameters used to differentiate both diagnoses were: severity of lymphocytic infiltration, the extent of epidermotropism, folliculotropism, presence of Pautrier's microabscesses, lymphocytes with cerebriform nuclei, and dermal fibroplasia. No immunohistochemical differences were found between them. Conclusion The clinical distinction between HTCD and HMF continues to be a challenge, therefore an extensive clinicopathological correlation must be performed. AbCD7 and AbCD62L were not useful to differentiate both dermatoses. This paper suggests that HTCD and HMF should be considered as the beginning and the end of the same clinical spectrum.

Background: Onychomycosis is one of the most common nail diseases and constitutes up to 50% of all nail conditions. It is a chronic fungal nail infection common in the HIV-infected population. Few studies have found fungal organisms in the nail without clinical evidence, and thus, termed subclinical onychomycosis. Objectives: We analyzed the nails of the HIV population in our hospital, searching for subclinical onychomycosis. Method: A distal nail clipping was stained with PAS and observed by a trained dermatopathologist. Results: All of our samples (n = 48) turned out to be negative for fungal structures. Conclusions: The epidemiology of onychomycosis is changing, treatment options are much better now, and diagnosis and infection detection are being done earlier. Therefore, we will continue to further study this disease in other patient populations so that we can compare our results and see whether the incidence of onychomycosis in the HIV population is now similar to that in those without HIV infection of the same age.

Introduction: There are no reports of the density of hair follicles in the scalp of Mexican mestizo population, necessitating the determination of normal references values for this population compared with other ethnic groups. Objective: To determine the average hair follicle count on the scalp in Mexican mestizo population. Materials and Methods: A total of 50 scalp samples (25 men and 25 women) from Mexican mestizo individuals aged between 19 and 60 years, with no clinical evidence of hair disease, obtained by biopsy punch at General Hospital “Dr. Manuel Gea González” were collected over 2 years. The total follicular density, vellus and terminal hair follicles, and the percentage in anagen and catagen-telogen phase were measured. χ2 was used as the basic statistical test. Results: The mean number of total hair follicles in our Mexican mestizo population was 23.2 ± 4.2, which is lower compared with Thais, Iranians, and Caucasians. However, the ratio of terminal and vellus hair follicles was higher than in Thais, Caucasians, and African-Americans. The percentage of terminal hairs in anagen phase was lower than in the other populations, and higher in telogen, without exceeding 15%, established as the normal reference value. There was an association between sex and terminal hairs in telogen phase (p < 0.05). The average follicular density per mm2 was slightly higher compared with African-Americans and Asians. Women had more terminal hairs than men. Conclusions: The density of total follicles is lower in the Mexican mestizo population compared with Iranians, Thais, and Caucasians. However, the greater number of terminal hairs compared to vellus hairs gives the appearance of greater overall volume. The results of this study can be used as a reference for diseases of the scalp in the Mexican population.