Cofactors and comorbidities of necrobiosis lipoidica: analysis of the German DRG data from 2012.

Background: Necrobiosis lipoidica (NL) is a rare granulomatous inflammatory skin disease of unknown pathophysiology. Its potential association with diabetes mellitus is well known. Other relevant cofactors and comorbidities are subject to controversial debate.
Patients and Methods: DRG (diagnosis-related groups) data of all inpatients with a coded primary or secondary diagnosis of NL treated at German hospitals in 2012 were evaluated.
Results: Data of 262 inpatient cases with the primary or secondary diagnosis of NL were analyzed. Women (63.4%; n = 166) were nearly twice as frequently affected as men (36.2%; n = 96). Most NL patients (14.8%) were in the age group between 50 and 55 years. Among comorbidities included in the metabolic syndrome complex, diabetes mellitus was the most common (34.4%; IDDM 20.6%, NIDDM 13.8%), while essential hypertension was observed in 9.2%, obesity in 4.6%, chronic heart failure in 4.1%, and dyslipidemias in 2.3% of cases. Leg ulcers were diagnosed in 7.3% of individuals; other venous disorders, in 5.7%.
Conclusions: Our data analysis describes one of the largest compilations of patient cases with the diagnosis of NL worldwide. Besides the well-known association with diabetes mellitus, there are numerous other potentially relevant cofactors and comorbidities that should be considered in the diagnosis and management of NL patients.
(© 2016 Deutsche Dermatologische Gesellschaft (DDG). Published by John Wiley & Sons Ltd.)