Supplementary Material for: Underlying Systemic Diseases in Interstitial Granulomatous Dermatitis and Palisaded Neutrophilic Granulomatous Dermatitis: A Systematic Review

<b><i>Background:</i></b> Interstitial granulomatous dermatitis (IGD) and palisaded neutrophilic granulomatous dermatitis (PNGD) are uncommon presentations of reactive granulomatous dermatitis. Histologic lesions characterized by IGD/PNGD patterns have been associated with systemic diseases, causing an unmet need for revealing clinical correlates. <b><i>Objective:</i></b> The aim of this study was to unravel the systemic diseases beyond dermatitis of IGD/PNGD. <b><i>Methods:</i></b> This study analyzed data from case studies, case series, and retrospective cohorts by searching PubMed, Embase, Web of Science, and the Cochrane Library, with no start date or language restrictions on Sep 4, 2021. <b><i>Results:</i></b> One hundred ninety-six publications were included (458 cases in total, 216 with details). Systemic diseases associated with IGD/PNGD were classified into 5 groups. Autoimmune disorders (<i>n</i> = 103, 47.6%) including rheumatoid arthritis (<i>n</i> = 51, 23.6%), systemic lupus erythematosus (<i>n</i> = 20, 9.3%), and others were the most common across all underlying diseases, followed by drug eruption (<i>n</i> = 52, 24.1%) such as tumor necrotic factor inhibitor reaction (<i>n</i> = 18, 8.3%) and malignancies (<i>n</i> = 27, 12.5%) such as hematologic malignancy (<i>n</i> = 20, 9.3%). The rest were infectious diseases (<i>n</i> = 12, 5.6%) and accidental conditions (<i>n</i> = 3, 1.4%). <b><i>Conclusion:</i></b> IGD/PNGD might be associated with autoimmune disorders, drug eruption, malignancies, infectious diseases, and accidental conditions. Patients with IGD/PNGD need further follow-up.

**背景：** 间质性肉芽肿性皮炎（Interstitial granulomatous dermatitis, IGD）与栅栏状中性粒细胞性肉芽肿性皮炎（palisaded neutrophilic granulomatous dermatitis, PNGD）均为反应性肉芽肿性皮炎的罕见临床表现。以IGD/PNGD为组织学特征的皮肤病变与系统性疾病存在关联，但目前临床对二者的临床关联尚未充分明确，存在未被满足的研究与临床需求。**目的：** 本研究旨在阐明IGD/PNGD患者所伴发的系统性疾病类型。**方法：** 本研究通过检索PubMed、Embase、Web of Science及Cochrane图书馆数据库，纳入截至2021年9月4日发表的病例报告、病例系列研究及回顾性队列研究数据，未设置起始检索年份与语言限制。**结果：** 本研究共纳入196篇文献，总计涉及458例病例，其中216例具备完整临床细节。与IGD/PNGD相关的系统性疾病可划分为5大类：自身免疫性疾病最为常见（n=103，占比47.6%），包括类风湿关节炎（n=51，占比23.6%）、系统性红斑狼疮（n=20，占比9.3%）及其他自身免疫病症；其次为药疹（n=52，占比24.1%），其中包含肿瘤坏死因子抑制剂相关不良反应（n=18，占比8.3%）；恶性肿瘤位列第三（n=27，占比12.5%），以血液系统恶性肿瘤最为典型（n=20，占比9.3%）；剩余类别分别为感染性疾病（n=12，占比5.6%）及意外诱因相关病症（n=3，占比1.4%）。**结论：** IGD/PNGD可与自身免疫性疾病、药疹、恶性肿瘤、感染性疾病及意外诱因相关疾病伴发。因此，IGD/PNGD患者需接受进一步的随访排查。