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Erythema Nodosum, Emergency Medicine

Basics

Description

- Immune-mediated response - 30-50% of the time etiology is idiopathic - Often a marker for underlying disease; specific etiologies include: - Drug reactions: - Oral contraceptives - Sulfonamides - Penicillins

- Malignancies such as lymphoma and leukemia - Catscratch disease - HIV infection - Rarely can be caused by vaccines for hepatitis and TB (BCG)

- GI symptoms with EN may be a marker for: - Inflammatory bowel disease - Bacterial gastroenteritis - Pancreatitis - Beh §et disease - A history of travel is important, as there are regional variations in etiology.

- EN migrans and chronic EN - Any type of panniculitis can resemble EN. - Differences can be determined histopathologically. - Other disorders include: - Periarteritis nodosum - Migratory thrombophlebitis - Superficial varicose thrombophlebitis - Scleroderma - Systemic lupus erythematosus - α1-antitrypsin deficiency - Beh §et syndrome - Lipodystrophies - Leukemic infiltration of fat - Panniculitis associated with steroid use, cold, and infection

  • Erythema nodosum (EN) is characterized by multiple symmetric, nonulcerative tender nodules on the extensor surface of the lowerextremities, typically in young adults.
  • Peak incidence in 3rd decade
  • More common in women (4:1)
  • Nodules are round with poorly demarcated edges and vary in size from 1 to 10 cm.
  • Skin lesions are initially red, become progressively ecchymotic appearing as they resolve over 3-6 wk.
  • Lesions are caused by inflammation of the septa between SC fat nodules (septal panniculitis).
  • Spontaneous regression of lesions within 3-6 wk
  • Major disease variants include:EN migrans (usually mild unilateral disease with little or no systemic symptoms)Chronic EN (lesions spread via extension, and associated systemic symptoms tend to be milder)

Etiology

  • Immune-mediated response
  • 30-50% of the time etiology is idiopathic
  • Often a marker for underlying disease; specific etiologies include:Drug reactions:Oral contraceptivesSulfonamidesPenicillinsInfections including:Streptococcal pharyngitisMycobacterium tuberculosis (TB)Atypical mycobacteriaCoccidioidomycosisHepatitisSyphilisChlamydiaRickettsiaSalmonellaCampylobacterYersiniaParasitesLeprosySystemic diseases:SarcoidosisInflammatory bowel diseaseBeh §et diseaseConnective tissue disordersMalignancies such as lymphoma and leukemiaCatscratch diseaseHIV infectionRarely can be caused by vaccines for hepatitis and TB (BCG)

Typically, EN begins 2-3 wk after onset of S. pharyngitis.

Diagnosis

Signs and Symptoms

  • Tender erythematous nodules symmetrically distributed on extensor surface of lower legs
  • Lesions occasionally occur on fingers, hands, arms, calves, and thighs.
  • In bedridden patients, dependent areas may be involved.
  • Fever, malaise, leukocytosis, arthralgias, arthritis, and unilateral or bilateral hilar adenopathy with any form of the disease

History

  • General symptoms may precede or accompany the rash:FeverGeneral malaisePolyarthralgias
  • GI symptoms with EN may be a marker for:Inflammatory bowel diseaseBacterial gastroenteritisPancreatitisBeh §et diseaseA history of travel is important, as there are regional variations in etiology.

Physical Exam

  • A careful exam is important, as underlying etiology varies by region.
  • Lesions are most common on the pretibial area but may occur on the thigh, upper extremities, neck and, rarely, the face.
  • Absence of lesions on the lower extremities is atypical, as are ulcerated lesions.
  • Lower-extremity edema may occur.
  • Adenopathy should be evaluated.

Essential Workup

Careful history and physical exam directed at detecting precipitating cause

Diagnosis Tests & Interpretation

Lab

  • CBC
  • Throat culture/ASO titer
  • ESR
  • Appropriate chemistry tests
  • Liver function tests
  • Serologies for coccidioidomycosis in endemic regions
  • TB skin testing in endemic regions

Imaging

CXR: Hilar adenopathy may be evidence of sarcoidosis, coccidioidomycosis, tuberculosis, or other fungal infections.

Diagnostic Procedures/Surgery

Definitive diagnosis made by deep elliptical biopsy and histopathologic evaluation (punch biopsy may be inadequate): Usually indicated for atypical cases or when TB is being considered

Differential Diagnosis

  • EN migrans and chronic EN
  • Any type of panniculitis can resemble EN.
  • Differences can be determined histopathologically.
  • Other disorders include:Periarteritis nodosumMigratory thrombophlebitisSuperficial varicose thrombophlebitisSclerodermaSystemic lupus erythematosusα1-antitrypsin deficiencyBeh §et syndromeLipodystrophiesLeukemic infiltration of fatPanniculitis associated with steroid use, cold, and infection

Treatment

  • Rare in children, S. pharyngitis is the most likely etiology.
  • Catscratch disease should be considered.

Pre-Hospital

Maintain universal precautions

Initial Stabilization/Therapy

Airway, breathing, and circulation (ABCs); IV, oxygen, monitoring as appropriate

Ed Treatment/Procedures

  • Treatment should be directed at underlying disease.
  • Supportive therapies include rest and analgesics.
  • Corticosteroids and potassium iodide may hasten resolution of symptoms.
  • Systemic corticosteroids are contraindicated in the presence of certain underlying infections such as TB or coccidioidomycosis, which may disseminate with their use.
  • Potassium iodide is contraindicated in hyperthyroid states.

Medication

  • Aspirin: 650 mg PO q4-6h PRN (peds: contraindicated)
  • Ibuprofen: 400-800 mg PO q8h (peds: 5-10 mg/kg PO q6h)
  • Indomethacin: 25-50 mg PO q8h
  • Potassium iodide/SSKI (used for resistant disease; contraindicated in hyperthyroidism): 900 mg PO daily for 3-4 wk
  • Systemic corticosteroids (prednisone): 40 mg/d PO; duration determined by primary physician

First Line

  • Rest/supportive care
  • NSAIDs
  • Treatment of underlying disease

Second Line

Follow-Up

Disposition

Admission Criteria

Dictated by the severity of symptoms and the etiologic agent

Discharge Criteria

  • Nontoxic patients, able to take PO fluids without difficulty
  • Scheduled follow-up should be arranged.

Issues for Referral

  • EN is usually self-limited and resolves in 3-6 wk.
  • Atypical cases may need excisional biopsy.
  • Steroid and potassium therapy needs primary physician monitoring.

Follow-Up Recommendations

  • Follow-up to assess for resolution with primary care physician or dermatologist.
  • Evaluation of underlying etiology may require specialist referral.

Pearls and Pitfalls

  • EN is usually idiopathic but may be the 1st sign of systemic disease.
  • Lesions may recur if underlying disease is not treated.
  • Atypical and chronic lesions may indicate an alternative diagnosis and need biopsy.
  • Patients taking potassium or steroids need close follow-up.

Additional Reading

  • Gilchrist H, Patterson JW. Erythema nodosum and erythema induratum (nodular vasculitis): Diagnosis and management. Dermatol Ther. 2010;23(4):320-327.
  • James JD, Berger TG, Elston DM. Andrews Disease of the Skin: Clinical Dermatology, 10th ed. Philadelphia, PA: WB Saunders; 2006.
  • Mert A, Kumbasar H, Ozaras R, et al. Erythema nodosum: An evaluation of 100 cases. Clin Exp Rheumatol. 2007;25:563-570.
  • Sarret C, Barbier C, Faucher R, et al. Erythema nodosum and adenopathy in a 15-year-old boy: Uncommon signs of cat scratch disease. Arch Pediatr. 2005;12:295-297.
  • Schwartz RA, Nervi SJ. Erythema nodosum: A sign of systemic disease. Am Fam Physician. 2007;75:695-700.

Codes

ICD9

  • 017.10 Erythema nodosum with hypersensitivity reaction in tuberculosis, unspecified
  • 695.2 Erythema nodosum

ICD10

  • A18.4 Tuberculosis of skin and subcutaneous tissue
  • L52 Erythema nodosum

SNOMED

  • 32861005 Erythema nodosum (disorder)
  • 74610006 Tuberculous erythema nodosum (disorder)
  • 76097009 Erythema nodosum migrans (disorder)
  • 69688007 Erythema nodosum, chronic form (disorder)
  • 240360007 Yersinia erythema nodosum (disorder)
  • 240411003 Erythema nodosum leprosum (disorder)
  • 297940005 Drug-induced erythema nodosum (disorder)
  • 78223000 Coccidioidomycosis with erythema nodosum (disorder)