Erythema nodosum and erythema induratum (nodular vasculitis): diagnosis and management

Abstract

Erythema nodosum is the most common type of panniculitis; it may be due to a variety of underlying infectious or otherwise antigenic stimuli. The pathogenesis remains to be elucidated, but both neutrophilic inflammation and granulomatous inflammation are implicated. Beyond treating underlying triggers, therapeutic options consist mainly of nonsteroidal anti-inflammatory drugs, symptomatic care, potassium iodide, and colchicine. Erythema induratum (nodular vasculitis) is a related but distinctly different clinicopathologic reaction pattern of the subcutaneous fat. It is classically caused by an antigenic stimulus from Mycobacterium tuberculosis but may be associated with several other underlying disorders. After appropriate antimicrobial treatment in tuberculous cases, therapy for erythema induratum is similar to options for erythema nodosum.

Erythema nodosum in an adolescent patient with cryopyrin‐associated periodic syndrome

“…It typically presents as tender, warm, erythematous subcutaneous nodules on pretibial areas and evolves into bruise‐like, nonscarring lesions over 2‐8 weeks. EN is often accompanied by fever, malaise, arthritis, and arthralgia, which can occur as a prodrome prior to cutaneous manifestation 7, 10. This condition is more common in younger women during the second and fourth decades of life 10…”

“…The pathogenesis of EN is still poorly understood, and 72% of cases are still classified as idiopathic 7, 8, 10. It has been hypothesized that activated neutrophils play a key role in causing the characteristic tissue inflammation 7, 10, 11, 12.…”

“…It has been hypothesized that activated neutrophils play a key role in causing the characteristic tissue inflammation 7, 10, 11, 12. EN is commonly associated pediatric immunopathological disorders including inflammatory bowel disease, Behcet's disease, and sarcoidosis 13.…”

“…The diagnosis of EN is established clinically, although histology may assist in atypical presentations. Histological examination will reveal septal panniculitis with infiltrates composed of mixed inflammatory cells (predominantly neutrophils in early lesions) 7, 8, 10. The inflammation is primarily seen in the perivascular region within the septa but may spill into the lobules.…”

“…The mainstay of treatment is identifying and removing the underlying trigger and symptomatic treatment; for the disease is usually self‐limiting. However, new lesions may occur up to 2 months from initial onset and recurrence is not uncommon (30%‐49%) 10. Nonsteroidal anti‐inflammatory medications, potassium iodide, and colchicine are commonly prescribed for symptomatic relief.…”