Luis Daniel Mazzuoccolo

Background: Dupilumab provides substantial clinical benefit in moderate‐to‐severe atopic dermatitis, but whether clinical improvement is accompanied by microstructural resolution on reflectance confocal microscopy (RCM) remains unclear. Objectives: To describe baseline clinical and RCM findings, evaluate longitudinal clinical and microstructural changes and explore associations between baseline RCM features and week 24 outcomes. Methods: We conducted a prospective real‐world cohort study at a tertiary academic hospital in Buenos Aires, Argentina. Consecutive paediatric and adult patients aged ≥6 months with moderate‐to‐severe atopic dermatitis initiating dupilumab were assessed at baseline, week 12 and week 24. Clinician‐reported outcomes, patient‐reported outcomes and prespecified binary RCM features were summarized at each visit. Paired baseline‐to‐week 24 analyses assessed within‐patient clinical changes and RCM feature transitions. Associations between baseline RCM findings and week 24 outcomes were explored using Fisher's exact tests and linear regression models. Results: Thirty‐seven patients were included; 19 (51.4%) were paediatric and 25 (67.6%) were male. Baseline disease burden was high, with median EASI 28.0 (IQR 19.0–33.0). Baseline RCM showed epidermal disorganization, spongiosis and dilated vessels in all patients, with dermo‐epidermal junction inflammation in 34/37 (91.9%). In paired baseline‐to‐week 24 analyses, median EASI decreased from 28 (IQR 18–32) to 2 (IQR 1–6), with a median individual improvement of 22 points; EASI‐75 was achieved by 76.2%. Several baseline‐positive confocal features resolved by week 24, including acanthosis (81.8%), hyperkeratosis (72.7%), parakeratosis (66.7%) and epidermal inflammation/exocytosis (64.7%). However, epidermal disorganization, spongiosis and dilated vessels remained frequent, including among EASI‐75 responders. Conclusions: Persistent RCM abnormalities, particularly epidermal disorganization, spongiosis and dilated vessels, were observed at week 24, even among EASI‐75 responders. These findings suggest that clinical response to dupilumab may not always coincide with complete microstructural normalization and that RCM may provide complementary information beyond clinical outcomes.

Introducción: En muchas oportunidades, se requiere establecer el grado de acuerdo entre dos o más observadores, ya sea como un fin en sí mismo o como paso intermedio en una investigación. En este tipo de estudios, la elección del diseño adecuado es crucial, ya que influye en la aplicabilidad y generalización de los métodos. Objetivos: En este artículo presentaremos -a propósito de un caso real de un trabajo que todavía está en curso- la metodología para estimar el grado de acuerdo entre dos o más observadores respecto de una variable categórica. Materiales y métodos: Para la definición de los coeficientes utilizados se realizó una búsqueda bibliográfica en Pubmed y en Google Scholar. Resultados: Se propone el uso del kappa de Fleiss ponderado y el AC2 de Gwet como métricas de acuerdo para este problema. El AC2 es un coeficiente nuevo que permite superar algunas de las limitaciones relacionadas con el kappa, en particular las paradojas descritas por Feinstein y Cichetti. Conclusión: En este artículo presentamos el diseño de un estudio para evaluar el grado de acuerdo interobservador y describimos en forma detallada la metodología, incluyendo las características de las jueces, de los sujetos y las categorías a evaluar, la elección del coeficiente de acuerdo y su interpretación y el cálculo de los intervalos de confianza.

OBJETIVO: Describir la prevalencia y las características epidemiológicas y clínicas de pacientes con prurigo crónico. MÉTODOS: Estudio descriptivo, de corte transversal, en pacientes adultos suscritos al Programa de Atención Médica del Hospital Italiano de Buenos Aires, Argentina (PMHI), entre 1 de enero de 2018 al 1 de enero de 2023. RESULTADOS: Se registraron 132,535 pacientes, de los que 144 padecías prurigo crónico; 105 (73%) eran mujeres con mediana de edad de 67.5 años (RIC 51-79). La prevalencia puntual de prurigo crónico fue de 0.11% (IC95%: 0.09-0.13%), significativamente mayor en mujeres que en hombres (0.13% [IC95%: 0.11-0.16%] vs 0.07% [IC95%: 0.05-0.09%], p<0.0006). Las manifestaciones más frecuentes fueron pápulas (90%) y excoriaciones (84.7%), seguido de placas (21.5%) y nódulos (18.7%). La mediana hasta el diagnóstico fue de 168 días (RIC 36-765). El tratamiento más prescrito fueron los emolientes, corticosteroides tópicos y antihistamínicos. CONCLUSIONES: La prevalencia del PC en nuestra cohorte difiere de la comunicada en otros países. A diferencia de estudios previos, no se evidenciaron asociaciones estadísticamente significativas con otras enfermedades cutáneas. El tratamiento que recibieron los pacientes fue discordante con el propuesto en las guías internacionales. PALABRAS CLAVE: Prurigo; Prurito; Prevalencia; Epidemiología; Argentina

Purpose: Inflammatory skin diseases, including psoriasis (PsO), atopic dermatitis (AD), hidradenitis suppurativa (HS), and alopecia areata (AA), are chronic immune-mediated disorders that substantially impair the quality of life and impose a growing socioeconomic burden. In Latin America (LA), these conditions unfold in the context of structural inequality, fragmented health systems, and limited epidemiological data. Our objective was to review the epidemiology, awareness, and treatment landscape of PsO, AD, HS, and AA in Latin America, highlighting regional guidelines, real-world studies, and unmet needs. Methods: A narrative review was performed by integrating data from peer-reviewed publications, national and regional guidelines, registry analyses, and real-world studies published until 2025. Results: The prevalence of PsO in LA ranges from 0.5% to 2%, AD affects 2– 3% of adults, HS prevalence is estimated at 0.3– 0.5%, and AA lifetime risk approximates 1– 2%. Across conditions, awareness among patients and non-specialists remains low, contributing to delayed diagnosis and undertreatment. National guidelines, recently updated in Argentina, Brazil, Colombia, and Mexico, broadly align with international standards, adapting recommendations to local resource and reimbursement constraints. Biologic and targeted therapies have transformed disease management; however, access remains inequitable, limited by high costs, fragmented insurance systems, and slow regulatory approval processes. Emerging real-world evidence from registries such as MEASURE-AD, RENAAC (AA), and national HS cohorts confirms therapeutic benefit but highlights persistent disparities and data gaps. Conclusion: Despite major advances in therapeutic innovation, LA faces continuing inequities in access and outcomes for inflammatory skin diseases. Coordinated regional registries, harmonized clinical guidelines, and policy reforms to accelerate drug approval and reimbursement are essential to achieve equitable dermatologic care. Plain Language Summary: Why we did this work? Many people in Latin America live with long-lasting skin conditions such as psoriasis, eczema (atopic dermatitis), hidradenitis suppurativa, and alopecia areata (patchy hair loss). These conditions can affect comfort, confidence, work, and relationships. New medicines can help, but access is uneven. We wrote this review to explain what is known about these conditions in Latin America and to show where care can improve. What we did and found? We read studies, national clinical guidelines, and real-world reports from across the region. We looked at how common these conditions are, how they are recognized, and how they are treated.Awareness is low among the public and among some non-specialist clinicians. This leads to late diagnosis, especially for hidradenitis suppurativa.Countries have created clinical guidelines that broadly match international standards. These guidelines support step-by-step care, from creams and light therapy to tablets and new targeted medicines.Access to advanced treatments is still limited. Long approval timelines, costs, and gaps between public and private care delay treatment for many people.Real-world studies from Latin America show that targeted medicines can improve symptoms and quality of life when people can get them. What this means? People in Latin America deserve timely, effective skin care no matter where they live or how much they earn. Clear guidelines now exist; the next step is to make them real in everyday clinics. Faster approval, fair insurance coverage, stronger primary-care training, and shared regional registries would help more people get the right treatment at the right time.

Purpose: This clinical case report aims to document the successful management of calcific arteriolopathy, also known as calciphylaxis, in a 74-year-old male patient with multiple comorbidities, including chronic kidney disease. The primary objectives were to highlight the effectiveness of a multidisciplinary approach -particularly the use of topical sodium thiosulfate- and to demonstrate the positive impact on glomerular filtration rate (GFR) following wound healing. Methods: The patient presented with two ulcers on the posterior aspect of the right leg, which developed after hospitalization for congestive heart failure. A comprehensive treatment strategy was employed, involving multiple medical specialties, including infectious disease, nephrology, and dermatology. Treatment included intravenous antibiotics, pain management, transitioning to new-generation anticoagulants, and the use of a unique ointment containing sodium thiosulfate for wound care. Results: After seven months, the patient achieved complete wound healing, and his glomerular filtration rate improved significantly. Three consecutive measurements of renal filtration parameters confirmed this positive impact. The topical application of sodium thiosulfate played a crucial role in wound healing, highlighting its potential as a treatment option for calciphylaxis. Conclusion: This case underscores the importance of interdisciplinary management in calcific arteriolopathy, addressing both underlying causes and localized wound care. The successful outcome and improved renal function following wound healing suggest that topical sodium thiosulfate can be a valuable treatment approach, particularly when systemic therapy is challenging. This report contributes to the limited literature on the topical use of sodium thiosulfate in calciphylaxis and emphasizes the need for comprehensive care in patients with this condition.