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Cutaneous leishmaniasis is atypical in Sri Lanka because Leishmania donovani, which typically causes visceral disease, is the causative agent. The origins of recently described hybrids between L. donovani and other Leishmania spp. usually responsible for cutaneous leishmaniasis remain unknown. Other endemic dermotropic Leishmania spp. have not been reported in Sri Lanka. Genome analysis of 27 clinical isolates from Sri Lanka and 32 Old World Leishmania spp. strains found 8 patient isolates clustered with L. tropica and 19 with L. donovani. The L. tropica isolates from Sri Lanka shared markers with strain LtK26 reported decades ago in India, indicating they were not products of recent interspecies hybridization. Because L. tropica was isolated from patients with leishmaniasis in Sri Lanka, our findings indicate L. donovani is not the only cause of cutaneous leishmaniasis in Sri Lanka and potentially explains a haplotype that led to interspecies dermotropic L. donovani hybrids.

Metastatic Crohn\'s disease is the rarest cutaneous manifestation of Crohn\'s disease, it presents as cutaneous lesions in areas that are anatomically non-contiguous with the gastrointestinal tract. It requires a high index of suspicion for diagnosis which is confirmed on histopathology. Infliximab can be an effective treatment.

BACKGROUND: Cutaneous squamous cell carcinoma (cSCC) is one of the most common skin cancers worldwide. Due to the ever-increasing sun exposure and life expectancy, cSCCs are increasing worldwide. The aim of our study was to identify specific risk factors leading to local and regional recurrences, determine patients\' survival rates, and identify best practices for the management of cSCC.
METHODS: This study retrospectively analyzed 1197 head and neck cSCCs in 945 patients who consecutively presented to the clinics from January 2007 to December 2016. Patients were followed up for a minimum of 18 months.
RESULTS: A total of 29 patients (3%) developed loco-regional recurrences (26 local, one regional, and two both local and regional) with a median time to recurrence of 25 (range, 1-81) months. The mean follow-up was 32 (range, 5-90) months. Treatment modality (p=0.027), depth of invasion (p<0.001), diameter > 20 mm (p<0.001), gender (p=0.022), histological differentiation (p<0.001), site of the lesion (p<0.001), perineural and intravascular invasion (p<0.001), positive lymphadenopathy (p=0.021), immunosuppression (p<0.001), and history of treatment (p=0.008) proved to be strong predictors for loco-regional recurrences. At one and five years after diagnosis, 95.6% and 59.9% of all patients were recurrence-free, respectively. The median survival time from recurrence was 2.6 years.
CONCLUSIONS: Our study identifies prognostic indicators for reoccurrence by analyzing data from a large continuous cohort in the management of cSCCs.

Scalp lesions associated with psoriasis and cutaneous leishmaniasis can be clinically indistinguishable, leading to misdiagnosis. Herein, we highlight a 70-year-old male initially misdiagnosed with psoriasis but subsequently confirmed to have cutaneous leishmaniasis. This emphasizes the importance of considering alternative diagnoses, especially in atypical presentations, to ensure accurate treatment.

Rosai-Dorfman disease (RDD) is a rare disorder characterized by excessive growth of histiocytes. We present a case of a 14-year-old female with cutaneous RDD who had a subcutaneous lump on her left arm for three years. The lump became tender and progressively larger over the past year. She had no systemic symptoms, and her physical examination revealed a mobile, tender lump. Laboratory tests were normal. Surgical excision of the lump was performed, and histopathological examination confirmed RDD with the presence of epithelioid histiocytes with eosinophilic and clear cytoplasm, along with emperipolesis and positive staining for CD68, CD163, S100, and OCT2. The patient was referred for follow-up and required no further treatment. RDD can present with subcutaneous masses without systemic symptoms, and it is important to consider RDD in the differential diagnosis of such cases. Surgical excision is the main treatment, and long-term monitoring is necessary due to the potential for disease recurrence. Awareness of cutaneous RDD presentations is crucial for accurate diagnosis and management.

A diagnosis of dermatomyositis requires recognition of distinct patterns of skin disease in combination with, and sometimes without, muscle weakness. Often, a striking contrast between involved and uninvolved areas is observed. Familiar patterns include eyelid and midfacial eruptions, Gottron papules/sign, and upper back (shawl sign), central chest (V/open collar sign), and lateral thigh (holster sign) involvement. More recently, new specific antibody/phenotype-associated patterns have been reported. We describe a case series of two distinct patterns of skin involvement in six adult patients with both classical and amyopathic dermatomyositis. Three had paraneoplastic disease. All had intermediate to richly pigmented skin; five were of Afro-Caribbean and one was of Asian-Caribbean descent. Four were men, and two were women. Ages ranged from 41 to 89 years. All patients had concomitant hallmark signs (facial, hand, and/or trunk signs). Three were amyopathic. The first pattern involved a sharply demarcated, horizontally oriented hyperpigmented patch/thin plaque across the shoulders and upper chest, extending up the anterior neck. The second was the combination of the classical upper back shawl distribution with distinct mid-back sparing and diffuse involvement of the lower back. Named patterns help with the recognition of skin rashes in dermatomyositis. Based on the current lexicon describing items of apparel, we liken the first pattern to a \"fur stole and turtleneck\" sign and the latter to a \"halter-back\" or \"reflected-shawl\" sign. Biopsies revealed hyperkeratosis and interface dermatitis, often with epidermal atrophy, compatible with dermatomyositis. These patterns perhaps represent the coalescence of already well-described signs, photo-exacerbation, koebnerization, mechanical stretch, and other currently unclear factors contributing to patterning in dermatomyositis. Pattern distribution recognition is particularly valuable in individuals with richly pigmented skin who may lack typical violaceous erythema. The distinct demarcation led to the initial misdiagnosis of allergic contact dermatitis or other exogenous dermatitis in most of our patients. Further work involves evaluation of antibody phenotype and internal involvement associations. Limitations include lack of specific antibody panels and longitudinal follow-up data.

Paraconiothyrium cyclothyrioides is a coelomycetous fungus species that was recently identified. We present a case of an elderly farmer with chronic skin lesions of the opisthenar caused by P. cyclothyrioides.

Histoplasmosis is a fungal infection caused by the fungus Histoplasma capsulatum. It can manifest in various ways, ranging from pulmonary to disseminated presentations. Most of the disseminated cases are seen in immunocompromised patients; here, we present an unusual case of an 81-year-old Mexican male with a history of cave exposure in his childhood, with 75 years of incubation period of the disease, who developed disseminated cutaneous histoplasmosis with no evident immunocompromising conditions. We considered the hypotheses of transient immunosuppression, CD4+ T lymphocytopenia, and immune senescence as the cause of this manifestation. The present case is also notable for its recurrence following therapy. This report underscores the challenges in diagnosing histoplasmosis in immunocompetent individuals and highlights the importance of long-term treatment and follow-up.

The CCR4 receptor is a pivotal target in cutaneous T-cell lymphoma (CTCL) therapy due to its role in impairing immune responses against malignant T-cells and expression profiles. Monoclonal antibodies like mogamulizumab effectively bind to CCR4, reducing tumour burden and enhancing patient outcomes by inhibiting the receptor\'s interaction with ligands, thereby hindering malignant T-cell migration and survival. Combining CCR4 antibodies with chemotherapy, radiation, and other drugs is being explored for synergistic effects. Additionally, small-molecular inhibitors, old pharmacological agents interacting with CCR4, and CAR-T therapies are under investigation. Challenges include drug resistance, off-target effects, and patient selection, addressed through ongoing trials refining protocols and identifying biomarkers. Despite advancements, real-life data for most of the emerging treatments are needed to temper expectations. In conclusion, CCR4-targeted therapies show promise for CTCL management, but challenges persist. Continued research aims to optimise treatments, enhance outcomes, and transform CTCL management. This review aims to elucidate the biological rationale and the several agents under various stages of development and clinical evaluation with the actual known data.