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Key Features

Essentials of Diagnosis

  • Painful red nodules without ulceration on anterior aspects of legs

  • Slow regression over several weeks to resemble contusions

  • Women are predominantly affected by a ratio of 10:1 over men

  • Some cases associated with infection, inflammatory bowel disease, or drug sensitivity

General Considerations

  • The disease may be associated with various infectious and noninfectious conditions

    • Infection: streptococcal, coccidioidomycosis, other fungal (eg, histoplasmosis, blastomycosis), tuberculosis, diverticulitis, syphilis, Yersinia enterocolitica

    • Other: sarcoidosis, medications (eg, oral contraceptives), inflammatory bowel disease, pregnancy, Behçet disease

Clinical Findings

Symptoms and Signs

  • The subcutaneous swellings are exquisitely tender and may be preceded by fever, malaise, and arthralgia

  • They are most often located on the anterior surfaces of the legs below the knees but may occur on the arms, trunk, and face

  • The lesions, 1–10 cm in diameter, are at first pink to red; with regression, all the various hues seen in a contusion can be observed

Differential Diagnosis

  • Erythema induratum (associated with tuberculosis)

  • Nodular vasculitis

  • Erythema multiforme

  • Lupus panniculitis

  • Poststeroid panniculitis

  • Contusions or bruises

  • Sweet syndrome (acute febrile neutrophilic dermatosis)

  • Subcutaneous fat necrosis (associated with pancreatitis)


Laboratory Tests

  • Evaluation of patients should include

    • Careful history and physical examination for prior upper respiratory infection or diarrheal illness

    • Symptoms of any deep fungal infection endemic to the area

    • Chest radiograph

    • Partial protein derivative (PPD)

    • Two consecutive ASO titers at 2- to 4-week intervals



  • See Table 6–2

  • First identify and treat the underlying cause

  • Primary therapy is with nonsteroidal anti-inflammatory drugs

  • Saturated solution of potassium iodide, 5–15 drops three times daily, may result in prompt involution in many cases

  • Systemic therapy directed against the lesions themselves may include use of corticosteroids unless contraindicated by associated infection



  • It usually lasts about 6 weeks and may recur

  • If no underlying cause is found, a significant underlying illness (usually sarcoidosis) will develop in only a small percentage of patients over the next year

When to Refer

  • If there is a question about the diagnosis, if recommended therapy is ineffective, or specialized treatment is necessary


Blake  T,  et al. Erythema nodosum—a review of an uncommon panniculitis. Dermatol Online J. 2014 Apr 16;20(4):22376.
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Chen  S,  et al. Mycobacterium tuberculosis infection is associated with the development of erythema nodosum and nodular vasculitis. PLoS One. 2013 May1;8(5):e62653.
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Chowaniec  M,  et al. Erythema nodosum—review of the literature. Reumatologia. 2016;54(2):79–82.
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De Simone  C,  et al. ...

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