What is the diagnosis and treatment for Erythema nodosum (EN)?

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From the Guidelines

Erythema nodosum should be treated with colchicine as the preferred option when it is the dominant lesion, as recommended by the EULAR guidelines for the management of Behçet disease 1. The treatment of erythema nodosum primarily focuses on addressing the underlying cause while managing symptoms.

Key Considerations

  • The decision to treat erythema nodosum depends on the perceived severity by the doctor and the patient, and treatment should be tailored according to how it affects the patient's quality of life.
  • Colchicine is widely used for the treatment of erythema nodosum, especially in cases where it is the dominant lesion, as stated in the EULAR recommendations 1.
  • In cases associated with inflammatory bowel disease, treatment is usually based on that of the underlying IBD, with systemic corticosteroids required in severe cases, and immunomodulators or anti-TNF agents used for relapsing and resistant forms 1.

Treatment Options

  • Colchicine (0.6mg twice daily) can be effective for recurrent cases of erythema nodosum.
  • Systemic corticosteroids like prednisone (20-40mg daily with gradual tapering) may be prescribed for 2-4 weeks in more severe cases.
  • Immunomodulators such as azathioprine or anti-TNF agents like infliximab or adalimumab may be used in resistant cases or when there are frequent relapses.

Important Considerations

  • Identifying and treating the underlying trigger is crucial for preventing future episodes of erythema nodosum.
  • A thorough medical evaluation, including throat cultures, chest X-ray, and appropriate blood tests, is important for all patients with erythema nodosum to determine the underlying cause.

From the Research

Definition and Characteristics of Erythema Nodosum

  • Erythema nodosum is the most frequent clinico-pathological variant of the panniculitides, characterized by inflammatory, tender, nodular lesions, usually located on the anterior aspects of the lower extremities 2.
  • The disorder is a cutaneous reaction consisting of symmetrical, tender, erythematous, warm nodules and raised plaques, often bilaterally distributed on the shins, ankles, and knees 2, 3.
  • The lesions typically do not ulcerate and heal without atrophy or scarring, with a color change from bright red to livid red or purplish, and finally to yellow or greenish 2.

Etiology and Associated Conditions

  • Erythema nodosum may be associated with a wide variety of diseases, including infections, sarcoidosis, rheumatologic diseases, inflammatory bowel diseases, medications, autoimmune disorders, pregnancy, and malignancies 2, 3, 4.
  • The most common identifiable causes are streptococcal infections, primary tuberculosis, sarcoidosis, Behçet disease, inflammatory bowel disease, drugs, and pregnancy 3, 4, 5.
  • Erythema nodosum can be the first sign of a systemic disease, and ruling out an underlying disease is imperative before diagnosing primary erythema nodosum 4.

Histopathology and Diagnostic Evaluation

  • Histopathologically, erythema nodosum is characterized by a mostly septal panniculitis with no vasculitis, and the presence of Miescher's radial granulomas 2.
  • Diagnostic evaluation includes a comprehensive history and physical examination, complete blood count with differential, erythrocyte sedimentation rate, C-reactive protein level, and testing for streptococcal infection 3.
  • A deep incisional or excisional biopsy specimen may be obtained for adequate visualization, and patients should be stratified by risk for tuberculosis 3.

Treatment and Management

  • Treatment of erythema nodosum should be directed to the underlying associated condition, if identified, and usually, nodules of erythema nodosum regress spontaneously within a few weeks 2, 5.
  • Supportive care, including bed rest, and pain management with nonsteroidal anti-inflammatory drugs, may be helpful 2, 3, 5.
  • Systemic corticosteroids are rarely indicated in erythema nodosum, and before these drugs are administered, an underlying infection should be ruled out 2.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Erythema nodosum.

Dermatology online journal, 2002

Research

Erythema nodosum: a sign of systemic disease.

American family physician, 2007

Research

Erythema Nodosum: A Practical Approach and Diagnostic Algorithm.

American journal of clinical dermatology, 2021

Research

Erythema nodosum.

Giornale italiano di dermatologia e venereologia : organo ufficiale, Societa italiana di dermatologia e sifilografia, 2013

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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