Alpsoy, Erkan

Abstract Background Small vessel vasculitides (SVV) comprise a heterogeneous group of cutaneous SVV (CSVV) that can be skin‐limited or systemic. Given their diverse forms and symptoms and the lack of a standardized diagnostic approach, it is crucial to establish clear and consensus‐driven recommendations for diagnosis. Objectives To standardize diagnosis for the detection of the type, extent, potential causes or underlying conditions of CSVV. Methods International experts comprised the panel. The Delphi panel data was collected through two rounds of questionnaires. Agreement was measured using an 11‐point Likert scale (0 = strongly disagree, 10 = strongly agree). A 7‐vote minimum was required for agreement on each statement. Delphi panel statements scoring 3–7 were discussed during the meeting. Results 20 experts participated in the first round of the Delphi panel, while 17 experts took part in the second. They agreed that the diagnosis of CSVV relies on a combination of clinical manifestations, laboratory findings and histopathology. Palpable purpura on the lower extremities is recognized as the most reliable hallmark for most SVV and a sign of immune complex vasculitis. When the latter is suspected, a skin biopsy for direct immunofluorescence (DIF) should be obtained from an early, partially blanchable macule because the type of perivascular immunoglobulin is important for further diagnosis. The proper selection of biopsy sites for routine HE biopsy depends on the morphology of lesions. A comprehensive medical history and selected laboratory testing should be conducted to investigate organ involvement, potential causes and associated conditions. The extent of diagnostic procedures should be based on the severity, duration, systemic symptoms and recurrence of SVV. Conclusions Experts reached a strong consensus on the management of CSVV patients, culminating in the first International Consensus Statement for adult CSVV. This statement proposes a practical management algorithm and underscores the importance of collaboration in rare diseases management.

Importance Hidradenitis suppurativa (HS) is a chronic inflammatory skin disease with a substantial burden. Standardized global prevalence estimates and data on associated sociodemographic and risk factors are lacking. Objective To estimate the global prevalence of HS and study differences in prevalence by age, sex, geographical location, body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), smoking status, gross domestic product (GDP), and Human Development Index (HDI). Data Sources and Study Selection Included studies were conducted using the standardized Global Hidradenitis Suppurativa Atlas methodology with finalized data collection before May 19, 2023. Studies were required to use a population-based sampling method and conduct clinical confirmation of HS diagnosis following a screening questionnaire. Data Extraction and Synthesis Data were independently extracted from relevant studies by 2 reviewers (D.B. and C.E.M.) using a standardized form. Extracted variables included geographic location, age, sex, BMI (median and BMI >30), smoking status, HS prevalence estimates (with 95% CIs), GDP, and HDI. A proportional meta-analysis using a random-effects model was conducted on the included studies. Main Outcomes and Measures The primary outcome was the point prevalence of HS, confirmed by clinical examination. Secondary outcomes included differences in HS prevalence by sex, age, BMI category, smoking status, and country-level socioeconomic indicators (GDP and HDI). All outcomes were prespecified before data analysis. Results The sample included 22 743 participants, identifying 247 patients with HS, across 25 studies in 23 countries spanning 6 continents. The median proportion of female patients with HS was 55.6%, and the median age was 34.5 years. While the prevalence estimates showed considerable inconsistency ( I 2 > 75%; τ 2 = 0.747), the overall random-effects global prevalence of HS was 0.99% (95% CI, 0.67%-1.46%). Female sex was the only factor observed to be associated with the prevalence estimates (β = 1.02; 95% CI, 1.01-1.03). Conclusions and Relevance In this meta-analysis, an estimated global prevalence of HS between 0.67% and 1.46% surpassed previous global estimates. Substantial global variations in HS prevalence were also observed. Female sex was the only factor associated with prevalence in this sample. Future studies assessing genetic, environmental, and etiological factors are warranted to explain the heterogeneity in prevalence.

Objective To prepare a dermatologic addendum to the 2012 revised International Chapel Hill Consensus Conference Nomenclature of Vasculitides ( CHCC 2012) to address vasculitides affecting the skin (D‐ CHCC ). The goal was to standardize the names and definitions for cutaneous vasculitis. Methods A nominal group technique with a facilitator was used to reach consensus on the D‐ CHCC nomenclature, using multiple face‐to‐face meetings, e‐mail discussions, and teleconferences. Results Standardized names, definitions, and descriptions were adopted for cutaneous components of systemic vasculitides (e.g., cutaneous IgA vasculitis as a component of systemic IgA vasculitis), skin‐limited variants of systemic vasculitides (e.g., skin‐limited IgA vasculitis, drug‐induced skin‐limited antineutrophil cytoplasmic antibody–associated vasculitis), and cutaneous single‐organ vasculitides that have no systemic counterparts (e.g., nodular vasculitis). Cutaneous vasculitides that were not included in the CHCC 2012 nomenclature were introduced. Conclusion Standardized names and definitions are a prerequisite for developing validated classification and diagnostic criteria for cutaneous vasculitis. Accurate identification of specifically defined variants of systemic and skin‐limited vasculitides requires knowledgeable integration of data from clinical, laboratory, and pathologic studies. This proposed nomenclature of vasculitides affecting the skin, the D‐ CHCC , provides a standard framework both for clinicians and for investigators.