Prevalence, demographics, and comorbidities associated with necrobiosis lipoidica: An analysis of national inpatient sample 2016-2019

Summary: Abstract Body: Necrobiosis lipoidica (NL) is a rare chronic inflammatory skin disorder frequently associated with diabetes. Epidemiological data on NL are limited due to its rarity. This study evaluated NL prevalence, gender differences, and its associations with diabetes, vascular, metabolic, autoimmune, and infectious comorbidities. National Inpatient Sample dataset of 36,731,521 patients was analyzed from 2016-2019. NL cases were identified using International Classification of Diseases 10 version (ICD-10) code L92.1, and comorbidities were flagged with corresponding ICD-10 codes. Chi-square tests and logistic regressions with odds ratios (ORs) were used to evaluate the associations between comorbidities in patients with and without NL. NL prevalence was 3.5 cases per million hospitalizations (130 cases out of 36.7 million). Out of the 130 cases of NL, 98 (75.37%) were female, and 32 (24.62%) were male, with a statistically significant association between gender and NL prevalence (p < 0.0001). The mean age was 56.69 years (range: 14–90). Type 2 diabetes was present in 39.23% of NL patients, and Type 1 diabetes in 13.85%. Common metabolic comorbidities included dyslipidemia (OR = 1.92, p = 0.0004), obesity (OR = 3.11, p < 0.0001), and hypothyroidism (OR = 2.17, p = 0.0003). Autoimmune conditions, such as rheumatoid arthritis (OR = 6.45, p < 0.0001) and systemic lupus erythematosus (OR = 4.54, p = 0.0042), were significantly associated with NL. Infectious complications like cellulitis (OR = 10.03, p < 0.0001) were markedly elevated. This analysis highlights NL’s rarity, its gender disparity, and its associations with diabetes and other comorbidities. These findings indicate that NL is not limited to diabetic patients, highlighting the importance of targeted screening and multidisciplinary care to address associated metabolic, vascular, and autoimmune conditions, especially among high-risk inpatient populations. Cassandra Sala¹, Ziyou Ren¹ 1. Dermatology, Northwestern University Feinberg School of Medicine, Chicago, IL, United States. Clinical Research: Epidemiology and Observational Research