Erythema Nodosum in Children: A Narrative Review and a Practical Approach

Abstract

Erythema nodosum (EN) is the most frequent form of panniculitis in children. We performed a literature review analyzing studies on pediatric EN published from 1990 to February 2022. EN is rare in pediatric age. It can be primary/idiopathic in 23–55% cases, or secondary in 47–77% cases. Secondary EN is related to a wide variety of conditions including infectious diseases, autoimmune disorders, malignancy, drugs, vaccinations, and pregnancy. The diagnosis of EN is clinical, based on the acute appearance of painful and red nodules localized to lower limbs, bilaterally distributed. If EN is diagnosed, basic work-up should include inflammatory markers, serum aminotransferases, lactate dehydrogenase, creatinine, protein electrophoresis, immunoglobulins, testing for streptococcal infection, and a tuberculin skin test. Based on the medical history and associated manifestations, further laboratory and radiological exams should be performed. The prognosis of EN is excellent, with spontaneous resolution in most patients within 2–6 weeks. Treatment, if needed, is addressed to the underlying condition. Despite being a rare manifestation in children, EN can be isolated or the first manifestation of a systemic or infectious condition. EN diagnosis is clinical, and a high index of suspicion is needed to perform investigations for the underlying disorders.

Erythema nodosum in the course of mycoplasma pneumoniae infection and pregnancy in a 17–year-old patient

“…In Poland, EN's most common infectious cause (accounting for up to 1/3 of cases) is infection with group A β-haemolytic streptococci [5]. Streptococcal pharyngitis usually precedes the onset of erythema nodosum by 2-3 weeks [2].…”

“…Skin manifestations occur in 10-25% of all Mycoplasma pneumoniae infections, including urticaria, vasculitis, Stevensen-Johnson syndrome, epidermal necrolysis, pityriasis rosea and the erythema mentioned above nodosum [8]. In the adult population, the second cause of the development of erythema nodosum is sarcoidosis, especially among young women, but it is rare in children [1,5]. Other causes of erythema nodosum include autoimmune diseases and cancer [1,2,5].…”

“…More frequent occurrence of EN in the winter and spring period has been proven. According to the literature, approximately 30-70% of cases are idiopathic [1,2,5]. There are few reports on this disease in children in the scientific literature.…”

Erythema nodosum associated with COVID19 infection: A pediatric case report and review of the literature

“… 1 Although uncommon, it can be triggered by viral infections in children. 2 In recent years, COVID19 infection and vaccination have been reported as a trigger of EN. We report a pediatric case of EN following COVID19 infection.…”

“…Although it is often idiopathic, the most frequent identifiable triggers are streptococcal infections, primary tuberculosis, sarcoidosis, Behçet disease, medications, pregnancy, and inflammatory bowel disease 1 . Although uncommon, it can be triggered by viral infections in children 2 . In recent years, COVID19 infection and vaccination have been reported as a trigger of EN.…”