The main task of the clinician is to identify and treat the primary cause. Many lesions in young patients resolve spontaneously in 1 to 2 months.[22]Starba A, Chowaniec M, Wiland P. Erythema nodosum - presentation of three cases. Reumatologia. 2016;54(2):83-5.
https://www.doi.org/10.5114/reum.2016.60218
http://www.ncbi.nlm.nih.gov/pubmed/27407285?tool=bestpractice.com
[3]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.
https://www.doi.org/10.1007/s40257-021-00592-w
http://www.ncbi.nlm.nih.gov/pubmed/33683567?tool=bestpractice.com
Mild to moderate symptoms
In patients with fever and troublesome arthralgias, symptoms can be controlled by bed rest, leg elevation, and nonsteroidal anti-inflammatory drugs (NSAIDs). The risk of deep vein thrombosis can be assessed if appropriate and compression stockings used if necessary.
Severe and refractory symptoms
In more severe or unresponsive cases, oral potassium iodide has been used successfully. While the mechanism of action of potassium iodide is unknown, it is postulated that it affects neutrophil chemotaxis or neutrophil chemotoxicity.[23]Sterling JB, Heymann WR. Potassium iodide in dermatology: a 19th century drug for the 21st century-uses, pharmacology, adverse effects, and contraindications. J Am Acad Dermatol. 2000 Oct;43(4):691-7.
http://www.ncbi.nlm.nih.gov/pubmed/11004629?tool=bestpractice.com
For persistent painful lesions, intralesional corticosteroid injections can be beneficial, but these are limited by procedural discomfort.
Systemic corticosteroids may be required if symptoms are severe or unresponsive, but should be avoided until the underlying cause is established, and then used in tapering courses over several weeks. Patients receiving prolonged therapy may be at risk for reactivation of tuberculosis and fungal infection, and sepsis may result if an underlying bacterial infection is overlooked.[24]American Thoracic Society. Targeted tuberculin testing and treatment of latent tuberculosis infection. Am J Respir Crit Care Med. 2000 Apr;161(4 pt 2):S221-47.
https://www.doi.org/10.1164/ajrccm.161.supplement_3.ats600
http://www.ncbi.nlm.nih.gov/pubmed/10764341?tool=bestpractice.com
[25]Gea-Banacloche JC, Opal SM, Jorgensen J, et al. Sepsis associated with immunosuppressive medications: an evidence-based review. Crit Care Med. 2004 Nov;32(11 suppl):S578-90.
http://www.ncbi.nlm.nih.gov/pubmed/15542967?tool=bestpractice.com
[26]Fardet L, Petersen I, Nazareth I. Common infections in patients prescribed systemic glucocorticoids in primary care: a population-based cohort study. PLoS Med. 2016 May;13(5):e1002024.
https://www.doi.org/10.1371/journal.pmed.1002024
http://www.ncbi.nlm.nih.gov/pubmed/27218256?tool=bestpractice.com
Treatment of underlying disorders
In people over 35 years old, erythema nodosum can be chronic and may be triggered by a more serious underlying disorder, such as rheumatoid arthritis or ulcerative colitis.[1]Bondi EE, Margolis DJ, Lazarus ZS. Panniculitis. In: Freedberg I, Eisen A, Wolff K, et al, eds. Fitzpatrick's dermatology in general medicine. 5th ed. New York, NY: McGraw-Hill; 1999: 1284-6.[2]Requena L, Requena C. Erythema nodosum (review). Dermatol Online J. 2002 Jun;8(1):4.
http://www.ncbi.nlm.nih.gov/pubmed/12165214?tool=bestpractice.com
Patients who have tuberculosis, brucellosis, or other underlying infections should receive the appropriate therapy.
Patients with sarcoidosis who develop erythema nodosum have a good prognosis and generally do not require corticosteroids, but they do require frequent monitoring to assess the disease course.