Abstract Background: Vitiligo is characterized by an autoimmune response targeting melanocytes, thus resulting in skin depigmentation. There are several genetic components involved in the development of vitiligo, of which various gene polymorphisms are currently considered as risk factors. For example, the CTLA4 (T-lymphocyte antigen 4) +49A/G (rs231775) and CT60 (rs3087243) gene variants have been associated with a predisposition for autoimmune diseases in different populations; however, their involvement in the development of vitiligo remains controversial. Objective: We evaluated the association between vitiligo and the CTLA4 +49A/G (rs231775) and CT60 (rs3087243) gene variants in a Mexican population. Methods: A total of 116 vitiligo patients and 117 control subjects from northeast Mexico were included in the study and analyzed through PCR-RFLP to determine whether there is an association between vitiligo and CTLA4 +49A/G (rs231775) and CT60 (rs3087243) gene variants. Results: No statistical difference was observed for both gene polymorphisms between vitiligo patients and controls (p > 0.05). Otherwise, vitiligo activity, family history of vitiligo, personal history of autoimmune diseases, or sex did not show any difference (p > 0.05). Conclusion: As suggested by the analysis of a northeastern Mexican population, the CTLA4 +49A/G (rs231775) and CT60 (rs3087243) gene variants do not constitute a risk factor in the development of vitiligo.

Abstract We report a 40-year-old man, with an unremarkable personal and family history, who presented for evaluation of an asymptomatic papule located on his right cheek. Histopathology revealed an encapsulated neoplasm within the dermis; composed by narrow, elongated, and wavy cells with an ill-defined cytoplasm, dense chromatin and tapered ends interspersed with collagen fibers. Pathologic findings were consistent with tissue of Antoni B pattern. The diagnosis was an infraorbital schwannoma. The incidental finding of rare tumors like this, should make clinicians consider a greater spectrum of differential diagnoses for a unilateral skin-colored papule on the cheek of patients.

Abstract This is a narrative review of azathioprine. This medication is immunomodulatory and immunosuppressive, and it has been used widely through different medical specialties to modify disease. It has been proven useful for several dermatoses and it has encountered success when used as an off-label indication for other dermatologic diseases. Its mechanism of action is described thoroughly, as well as precautions for monitoring adequate levels in patients using it. Dermatologists should also be aware of the possible adverse events it may present. In dermatology it can be used in bullous and autoimmune diseases, and in other conditions, including intractable pruritus, atopic dermatitis, photodermatoses, psoriasis, and others. Azathioprine offers an alternative as a steroid-sparing agent and this review helps dermatologists prescribe it safely to all patients who require it.

Abstract Background: Alopecia areata is an autoimmune disease that produces non-scarring hair loss around the body. Gene variants of the cytotoxic T-lymphocyte antigen 4 (CTLA4) gene, a negative regulator of T-cell response, have been associated with a predisposition to autoimmune diseases in different populations; however, the involvement of these genetic variants in the development of AA is controversial. Objective: The present study evaluated the potential association of two CTLA4 gene variants with alopecia areata in a Mexican population. Methods: We genotyped +49AG (rs231775) and CT60 (rs3087243) variants in 50 AA patients and 100 healthy control participants through PCR-RFLP. Results: No statistical difference was observed for either of the gene variants regarding allele or genotype frequencies between AA patients and the controls when the parameters of family/personal history of autoimmune diseases or gender were considered (p > 0.05). Study limitations: Small sample size of patients and the data were obtained from Northeast Mexico population. Conclusion: The genetic variants rs231775 and rs3087243 of the CTLA4 gene are not a risk factor for the development of alopecia areata in the analyzed Mexican population.

Abstract Capecitabine is a prodrug used primarily as a chemotherapeutic agent. Despite its good tolerance, it has several adverse effects, including the appearance of eruptive nevi. We present the case of a patient, with a history of EC IV breast adenocarcinoma and superficial extension melanoma, which developed 2 weeks after the start of therapy with capecitabine multiple eruptive palmoplantar pigmented lesions, with diverse benign dermatoscopic patterns. With the increasing incidence of solid tumors, these agents are being more used. It is important that the treating physician knows its adverse effects and apply non-invasive diagnostic tools like dermoscopy to avoid unnecessary biopsies.

Resumen La capecitabina es un profármaco utilizado sobre todo como medicamento quimioterapéutico. A pesar de su buena tolerancia, produce diversos efectos adversos como la aparición de nevos eruptivos. Se presenta el caso de una paciente, con antecedentes de adenocarcinoma de mama (EC IV) y melanoma de extensión superficial, que desarrolló dos semanas posteriores al inicio del tratamiento con capecitabina múltiples lesiones eruptivas pigmentadas palmoplantares, con patrones variados benignos a la dermatoscopia. Con el incremento de las neoplasias sólidas, estos agentes se utilizan cada vez más. Es importante que el médico tratante conozca sus efectos adversos y aplique herramientas diagnósticas no invasivas como la dermatoscopia para evitar biopsias innecesarias.

Abstract: Background: Vitiligo is characterized by a lack of pigmentation in the skin. To date, there are no studies that analyze the changes in gene expression in the skin of vitiligo patients in response to narrow-band ultraviolet B (nb-UVB) phototherapy treatment. Objective: Explore the usefulness of new generation RNA sequencing in the identification of gene expression changes in the skin of vitiligo patients treated with nb-UVB phototherapy. Methods: Four skin biopsies (4mm in diameter) were collected from 45 Mexican vitiligo vulgaris patients, 2 specimens before and 2 after treatment with nb-UVB phototherapy, obtained from pigmented and non-pigmented tissue. RNA extracted from the biopsies was analyzed using the Illumina TruSeq Targeted RNA Expression protocol to study the expression of genes that participate in pathways of skin homeostasis. The 2 groups were compared using Student's t-test and the Mann-Whitney U-test. Results: The expression analysis identified differences in 12 genes included in this study after comparing the samples obtained before and after treatment: 5 genes involved in skin pigmentation, 2 genes involved in apoptosis, 2 genes involved in cell survival, 2 genes involved in oxidative stress responses and 1 gene involved in signal transduction mechanisms (p<0.05). Study limitations: The small size of skin biopsies limits the amount of RNA obtained, the number of genes to be analyzed and the use of conventional techniques such as RT-qPCR. Conclusion: We demonstrated usefulness of new generation RNA sequencing in the identification of gene expression changes, in addition to identifying new targets in the study of vitiligo.

Abstract: Background: Pigmented lesions on acral sites are common; clinical differentiation of nevi and early melanoma can be challenging. In these cases, dermoscopy can provide a more accurate diagnosis. Most dermoscopic patterns on acral skin have been described in Asian and European populations, while there are few studies in Latin American populations. Objectives: To determine the frequency of pigmented lesions in volar skin and their dermoscopic patterns in a Mexican population. Methods: An observational, descriptive, cross-sectional study was performed in Hispanic patients with the presence of at least one pigmented lesion on acral skin. Clinical and dermoscopic images were obtained. These were subsequently evaluated independently by two dermatologists trained and experienced in dermoscopy. Results: A total of 582 pigmented lesions on volar skin were diagnosed in 321 patients. Overall, prevalence of acral pigmented lesions on volar skin was 6.8%. For both observers, parallel furrows were the most frequent pattern described, but for observer 2, a lattice-like pattern was prevalent on the toes and a homogeneous pattern on the sides of the feet. There was lower inter-observer agreement, with a kappa index of 0.144. Study limitations: The lesions were not biopsied, so clinical-histological correlation could not be performed. The study did not correlate dermoscopic patterns with age. Conclusions. As previously reported by other authors, parallel furrows were the most frequently found dermoscopic pattern on palmoplantar skin.

Abstract: Purpura is defined as a visible hemorrhage in the skin or mucosa, which is not evanescent upon pressure. Proper classification allows a better patient approach due to its multiple diagnoses. Purpuras can be categorized by size, morphology, and other characteristics. The course varies according to the etiology, as do the diagnostic approach and treatment. This review discusses pigmented purpuras and some cutaneous vascular occlusion syndromes.

Abstract: Ecthyma gangrenosum is a rare skin infection classically associated with Pseudomonas aeruginosa. We performed a retrospective study of all cases diagnosed with ecthyma gangrenosum from 2004-2010 in a university hospital in Mexico (8 cases, 5 female patients and 3 male patients, ages between 4 months and 2 years). The most common risk factor for ecthyma gangrenosum is neutropenia in immunocompromised patients. In previously healthy patients, immunological evaluation is important to rule out underlying immunodeficiency. Ecthyma gangrenosum in healthy patients has a high mortality rate and early diagnosis and aggressive antibiotic treatment is imperative as it can improve patients' prognosis.

Abstract Cutaneous mucormycosis is an emerging fungal infection caused by opportunistic fungi of the phylum Glomeromycota. It is frequent in poorly controlled diabetic patients and individuals with immunosuppression. It is usually acquired by direct inoculation through trauma. The clinical presentation is nonspecific, but an indurated plaque that rapidly evolves to necrosis is a common finding. Diagnosis should be confirmed by demonstration of the etiological agent and new molecular diagnostic tools have recently been described. It is an invasive life-threatening disease and in order to improve survival, a prompt diagnosis and multidisciplinary management should be provided. The treatment of choice is amphotericin B, but new azoles, such as posaconazole and isavuconazole, must be considered.

Abstract: Acrospiroma, also known as hidradenoma, is a rare cutaneous tumor that has several histological characteristics. As a consequence, a high index of suspicion is necessary for its diagnosis. Here we report a case that illustrates the importance of a good clinical-pathologic correlation in order to recognize this disease.

AbstractCoccidioidomycosis is a highly prevalent disease in the Western hemisphere. It is considered one of the most virulent primary fungal infections. Coccidioides species live in arid and semi-arid regions, causing mainly pulmonary infection through inhalation of arthroconidia although many other organs can be affected. Primary inoculation is rare. Since the first case of coccidioidomycosis was reported in 1892, the skin has been identified as an important target of this disease. Knowledge of cutaneous clinical forms of this infection is important and very useful for establishing prompt diagnosis and treatment. The purpose of this article is to provide a review of this infection, emphasizing its cutaneous manifestations, diagnostic methods and current treatment.