Erythema nodosum

Overview 
Theory 
Diagnosis 
Management 
Follow up 
Resources 

Evidence last reviewed: 19 Sep 2026

Topic last updated: 13 Oct 2026

Erythema nodosum (EN) presents with tender, nonulcerated, erythematous nodules located most commonly over the shins, and may sometimes be associated with arthralgia and fever.

Lesions occur as a response to a variety of conditions, including infection, chronic inflammatory disease, autoimmune disease, malignancy, and pregnancy. They are also related to the ingestion of certain drugs.

Histopathology demonstrates a septal panniculitis without vasculitis. Miescher radial granulomas are a diagnostic feature, but are not necessary for confirmation.

Treatment consists of supportive care, including bed rest and leg elevation. Nonsteroidal anti-inflammatory drugs (NSAIDs) can be used for arthralgia and fever. Potassium iodide and intralesional or oral corticosteroids may be used in refractory cases. Nodules may also resolve spontaneously. Healing occurs without atrophy or scarring.

Definition

EN is a common cutaneous hypersensitivity reaction consisting of erythematous, tender nodules most commonly located over the shins, but also reported over the thighs, upper extremities, calves, buttocks, and face.[1] Fever and arthralgia may sometimes be present.[1][2] EN is the most common inflammatory condition of the subcutaneous fat or panniculitis.[2]

Lesions typically arise acutely as single or clustered, symmetrical tender patches, later evolving into painful nodules over the course of several days.[1] The nodules are usually associated with extravasated blood, resulting in a red appearance, gradually turning violaceous, resembling bruises.[2] As new crops of nodules may form weeks after the initial presentation, lesions at varying stages of resolution may coexist.[1][2] Microscopy of these lesions demonstrates a septal panniculitis without vasculitis.[2] Lesions usually resolve within 1-8 weeks, healing without ulceration or scarring.[2][3]

History and exam

Key diagnostic factors

nodules on shins
uveitis, red eyes, retinal nodules, or candle-wax drippings
nodules on skin areas other than the shin

Full details

Other diagnostic factors

joint pains
fever
diarrhea, constipation, abdominal pain, hematochezia
enlarged spleen
miliary nodules on the retina

Full details

Risk factors

streptococcal infection
sarcoidosis
tuberculosis
coccidioidomycosis
histoplasmosis
blastomycosis
Behcet disease
brucellosis
use of certain drugs
use of certain vaccines
psittacosis
inflammatory bowel disease
pregnancy
malignancy

Full details

Diagnostic tests

1st tests to order

CBC
antistreptolysin-O titer
chest x-ray
tuberculin skin test, interferon-gamma release assay

Full details

Tests to consider

deep punch biopsies including subcutaneous fat or incisional biopsies
serum ACE level
skin lesion biopsy
coccidioidin skin test
histoplasmin skin test
blastomycosis serology
brucellosis serology
psittacosis serology
x-ray symptomatic joints
rheumatoid factor testing
stool cultures
coproparasitoscopic stool study
multiple-pathogen nucleic acid amplification test (e.g., polymerase chain reaction) of stool
colonoscopy
urine or serum pregnancy test

Full details

Treatment algorithm

ACUTE

mild to moderately severe symptoms

severe refractory symptoms

Contributors

Authors

Daniela Kroshinsky, MD, MPH

Professor of Dermatology

Vice Chair of Strategic Initiatives and Faculty Affairs

Director of Pediatric Dermatology

Duke University Medical Center

Durham, NC

Disclosures

DK declares that she has no competing interests.

Acknowledgements

Dr Daniela Kroshinsky would like to gratefully acknowledge Dr Om P. Sharma, a previous contributor to this topic. Dr Kroshinsky would also like to thank Priyanka Vedak for her contribution to this topic. We would like to gratefully acknowledge the contribution of the late Elisabeth Higgins (Consultant Dermatologist, King’s College Hospital) for her peer review of this topic.

Disclosures

OPS declared that he had no competing interests. PV declared that she had no competing interests. EH declared that she had no competing interests.

Peer reviewers

Robert T. Brodell, MD

Professor of Internal Medicine

Clinical Professor of Dermatopathology

Northeastern Ohio Universities College of Medicine

Warren

Associate Clinical Professor of Dermatology

Case Western Reserve University School of Medicine

Cleveland, OH

Disclosures

RTB declares that he has no competing interests.

Peer reviewer acknowledgements

BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.

Disclosures

Peer reviewer affiliations and disclosures pertain to the time of the review.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Requena L, Requena C. Erythema nodosum. Dermatol Online J. 2002 Jun;8(1):4.Full text Abstract

Pérez-Garza DM, Chavez-Alvarez S, Ocampo-Candiani J, et al. Erythema nodosum: a practical approach and diagnostic algorithm. Am J Clin Dermatol. 2021 May;22(3):367-78.Full text Abstract

Schwartz RA, Nervi SJ. Erythema nodosum: a sign of systemic disease. Am Fam Physician. 2007 Mar 1;75(5):695-700.Full text Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials
- Weber-Christian disease
- Alpha-1 antitrypsin deficiency
- Nodular vasculitis (erythema induratum or Bazin disease)
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Erythema nodosum

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic tests

1st tests to order

Tests to consider

Treatment algorithm

mild to moderately severe symptoms

severe refractory symptoms

Contributors

Authors

Daniela Kroshinsky, MD, MPH

Disclosures

Acknowledgements

Disclosures

Peer reviewers

Robert T. Brodell, MD

Disclosures

Peer reviewer acknowledgements

Disclosures

References

Key articles

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.

Differentials

Log in or subscribe to access all of BMJ Best Practice

Log in or subscribe to access all of BMJ Best Practice

Log in to access all of BMJ Best Practice