Issue 5/2026
Vasilev, T., Temelkova, K. Clinic of Rheumatology, Children’s Hospital “Ivan Mitev” – Sofia
Department of Pediatrics, Medical University – Sofia
Erythema nodosum (EN) is the most common form of septal panniculitis in children and is characterized by painful subcutaneous nodules predominantly located on the anterior aspects of the lower legs. It is considered a reactive immune-mediated condition associated with a wide spectrum of etiological factors, most commonly infectious. In pediatric populations, the leading causes include Streptococcus pyogenes, Mycobacterium tuberculosis, and gastrointestinal pathogens, while viral infections, including SARS-CoV-2, have gained increasing relevance. Non-infectious causes encompass inflammatory bowel diseases, sarcoidosis, Behçet disease, and drug-induced reactions. The pathogenesis of EN involves immune complex-mediated inflammation with activation of Th1 and Th17 pathways and increased production of proinflammatory cytokines such as TNF-α and IL-6. Diagnosis is primarily clinical but requires a systematic evaluation to identify the underlying cause. Management focuses on treating the underlying condition and providing symptomatic relief, while systemic corticosteroids and biologic agents may be required in severe or recurrent cases. EN generally has a favorable prognosis in children but remains an important clinical marker of underlying systemic disease, necessitating a multidisciplinary approach.
Key words: erythema nodosum, children, panniculitis, immunopathogenesis
Adress for correspondence:
Teodor Vasilev, MD, PhD
Clinic of Rheumatology,
Children’s Hospital “Ivan Mitev” – Sofia
11, „Аcad. Ivan Geshov“, Blvd.
1612, Sofia
e-mail: tvasilev@medfac.mu-sofia.bg