Immunoglobulin G4–related disease (IgG4-RD) is an uncommon fibro-inflammatory process characterized by the infiltration of tissues and organs and a typically dramatic response to glucocorticoids. Its relapsing–remitting course, multisystemic involvement, and variability in epidemiological and prognostic features pose a significant diagnostic challenge for clinicians. Despite their effectiveness in symptom relief, prolonged glucocorticoid use remains a challenge in IgG4-RD management, prompting the search for steroid-sparing alternatives. Although rituximab has recently demonstrated efficacy in the treatment of IgG4-RD, no consensus exists regarding the optimal maintenance regimen. The emergence of new B-cell–targeted therapies and other immunomodulators represents a promising step toward more personalized treatment approaches. In this review, we provide an updated and integrative overview of the emerging treatment strategies for IgG4-RD, highlighting future directions towards individualized management.

This document provides an updated overview of the molecular mechanisms underlying pulmonary fibrosis associated with Systemic Sclerosis (SSc). It summarizes current knowledge on how immune activation, vascular injury, and impaired tissue repair contribute to interstitial lung disease (ILD), which is the most serious and life-threatening complication of SSc. SSc is a rare autoimmune disorder involving vascular dysfunction and progressive fibrosis of the skin and internal organs. In the lungs, the interaction between immune and vascular abnormalities and excessive extracellular matrix deposition leads to irreversible structural damage. These processes occur through complex, multifactorial mechanisms that are only partially understood. The review examines recent evidence on the cellular mediators, signaling pathways, and epigenetic alterations involved in ILD-SSc pathogenesis. It also discusses the potential roles of genetic predisposition, environmental factors, and autoantibody profiles in disease heterogeneity. Finally, it highlights emerging therapeutic strategies that target these molecular mechanisms. This work aims to integrate these advances to provide a clearer understanding of the biological basis of SSc-associated pulmonary fibrosis and support the development of novel diagnostic and therapeutic approaches that may improve patient outcomes.

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis characterized by asthma, eosinophilia, and necrotizing inflammation of small- to medium-sized vessels. Accumulating evidence indicates that EGPA is a polygenic and heterogeneous disorder comprising distinct antineutrophil cytoplasmic antibody (ANCA)–defined endotypes with divergent genetic backgrounds, immune pathways, and clinical phenotypes. Its pathogenesis reflects the convergence of epithelial–alarmin signaling, type 2 inflammation, eosinophil effector mechanisms, and B-cell/autoantibody responses, with myeloperoxidase (MPO)-ANCA serving as a hallmark of the vasculitic subset. Recent advances in genomics, immunology, and multi-omics profiling have uncovered biomarkers and molecular circuits sustaining disease activity and guiding therapeutic stratification. The identification of the interleukin (IL)-5–eosinophil axis, epithelial-derived alarmins, and B-cell/IgG4 networks as central pathogenic nodes has enabled the development of targeted biologic therapies that are redefining treatment paradigms. Benralizumab (anti-IL-5Rα) has recently been approved for EGPA following the phase 3 head-to-head MANDARA trial, which demonstrated non-inferiority to mepolizumab in achieving remission (BVAS = 0 with ≤4 mg/day prednisone equivalent) at weeks 36 and 48. These results, together with the established efficacy of mepolizumab, inform practical selection between IL-5 and IL-5Rα blockade and support glucocorticoid-sparing approaches. A structured literature search (2015–2025) was conducted in PubMed, Scopus, and Web of Science to identify recent advances in epidemiology, genetics, biomarkers, and targeted therapies for EGPA. This updated review integrates molecular insights, clinical endotypes, and therapeutic innovations to outline current evidence and future precision-medicine strategies aimed at improving long-term patient outcomes.

Neutrophilic dermatoses (NDs) are a group of noninfectious disorders characterized by the presence of a sterile neutrophilic infiltrate without vasculitis histopathology. Their physiopathology is not fully understood. The association between neutrophilic dermatoses and autoinflammatory diseases has led some authors to propose that both are part of the same spectrum of diseases. The classification of NDs depends on clinical and histopathological features. This review focuses on the recent developments of treatments in these pathologies.

La Kikuchi-Fujimoto o linfadenitis histiocítica necrotizante es una enfermedad rara, habitualmente benigna y autolimitada. Sin embargo, en ocasiones se asocia a diferentes manifestaciones sistémicas que pueden condicionar una mortalidad significativa si no se identifican y tratan. Presentamos el caso de una paciente adulta con fiebre y adenopatías con diagnóstico histopatológico de enfermedad de Kikuchi-Fujimoto asociado a síndrome de activación macrofágica y meningitis aséptica. Se realiza también una breve revisión de la literatura sobre esta patología y sus manifestaciones sistémicas asociadas.