Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
Medical Statistics Unit, Department of Learning, Informatics, Management and Ethics, Karolinska Institutet, Stockholm, Sweden.
Acta Derm Venereol. 2023 Nov 16;103:adv13210. doi: 10.2340/actadv.v103.13210.
Dermatitis herpetiformis has been investigated in the past; however, only a limited number of studies have reported its incidence based on validated nationwide population-based registries. To address this gap, the aims of this study are to estimate the incidence of dermatitis herpetiformis in Sweden and to validate the National Patient Register (NPR) for diagnosis of dermatitis herpetiformis. A population-based open cohort study was conducted, including all patients diagnosed with dermatitis herpetiformis (International Classification of Diseases 10th revision; ICD-10 code L13.0) in Sweden from 2005 to 2018 (n = 1,724), identified from the NPR. The diagnosis of dermatitis herpetiformis in the NPR was validated using medical records, histopathological and immunopathological data, yielding a positive predictive value (PPV) of 62.5%. The mean annual incidence of dermatitis herpetiformis was 0.93/100,000 (95% confidence interval 0.79-1.08), female to male ratio 1:1, and mean age at diagnosis 60.9 years. In conclusion, this large nationwide cohort study showed a low validity for diagnosis of dermatitis herpetiformis in the NPR, and the adjusted incidence rate of dermatitis herpetiformis in Sweden was estimated to be 0.93/100,000, which is lower than that in previous Swedish studies.
疱疹样皮炎既往已有研究，但仅有少数研究基于经过验证的全国性基于人群的登记处报告了其发病率。为了弥补这一空白，本研究旨在估计瑞典疱疹样皮炎的发病率，并验证国家患者登记处（NPR）对疱疹样皮炎的诊断。进行了一项基于人群的开放性队列研究，纳入了 2005 年至 2018 年期间在瑞典根据国际疾病分类第 10 次修订版（ICD-10 编码 L13.0）确诊的所有疱疹样皮炎患者（n=1724），这些患者均来自 NPR。通过病历、组织病理学和免疫病理学数据验证了 NPR 中疱疹样皮炎的诊断，其阳性预测值（PPV）为 62.5%。疱疹样皮炎的年平均发病率为 0.93/100,000（95%置信区间 0.79-1.08），男女比例为 1:1，诊断时的平均年龄为 60.9 岁。总之，这项大型全国性队列研究表明，NPR 对疱疹样皮炎的诊断准确性较低，瑞典调整后的疱疹样皮炎发病率估计为 0.93/100,000，低于此前瑞典的研究结果。
