Clinical, epidemiological, and etiological changes in erythema nodosum

Background: Erythema nodosum (EN) is the most common type of panniculitis, commonly secondary to infectious diseases. Objectives: To elucidate the causative factors and the clinical presentation of patients with EN (2004–2014) and to compare their data to those reported in a previous study. Methods: A retrospective study was conducted of all patients diagnosed with EN who were hospitalized at Soroka University Medical Center (2004–2014). The clinical, demographic, and laboratory characteristics of the patients were compared to those in a cohort of patients diagnosed with EN from 1973–1982. Results: The study comprised 45 patients with a diagnosis of EN. The most common symptoms of patients hospitalized with EN were arthritis or arthralgia (27% of patients). Patients with EN, compared to those reported in 1987, has significantly lower rates of fever (18% vs. 62% P < 0.001), streptococcal infection (16% vs. 44%, P = 0.003), and joint involvement (27% vs. 66%, P < 0.001). In addition, fewer patients had idiopathic causes of EN (9% vs. 32%, P = 0.006). Conclusions: In the past decades, clinical, epidemiological, and etiological changes have occurred in EN patients. The lowering in rate of fever, streptococcal infection, and joint involvement in patients with EN are probably explained by improvements in socioeconomic conditions. The significantly decreasing rate of idiopathic causes of EN is possibly due to the greater diagnostic accuracy of modern medicine. The results of the present study demonstrate the impact of improvements in socioeconomic conditions and access to healthcare on disease presentation.