Israel Medical Association Journal

Inflammatory myopathies include polymyositis, necrotizing autoimmune myositis, dermatomyositis, juvenile inflammatory myopathy, and inclusion body myositis. These diseases are classified based on the different clinical and pathological characteristics unique to each of them [1]. Dermatomyositis is a rare disease with an incidence of 6–10 cases/1,000,000 a year with the highest incidence in the 7th decade of life as reported by a Norwegian cohort in a Caucasian population [2].

Diagnosis of dermatomyositis is based on typical signs and symptoms combined with laboratory results, imaging, and electromyography findings and muscle biopsy. Historically, the diagnosis of dermatomyositis was based on the classification criteria named after Bohan and Peter published in 1975. Many other classification criteria were proposed subsequently, the latter by the European League Against Rheumatism/American College of Rheumatology (EULAR/ACR), which were published in 2020 [3].

The clinical features of dermatomyositis are diverse. Skin manifestations can accompany or precede muscle weakness. Classical skin findings include periorbital heliotrope rash and a rash of the upper chest, back, and shoulders, known as the V sign and shawl sign respectively, as well as the Gottron's papules on the knuckles. Another skin appearance is subcutaneous calcifications that break periodically through the skin causing ulcerations. Dermatomyositis usually manifests as a symmetrical proximal muscle weakness but can present with preserved strength called amyopathic dermatomyositis [1].

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.