- Author: Jeanette L Hebel, MD; Chief Editor: William D James, MD more...
Erythema nodosum (EN) is an acute, nodular, erythematous eruption that usually is limited to the extensor aspects of the lower legs. Chronic or recurrent erythema nodosum is rare but may occur. Erythema nodosum is presumed to be a hypersensitivity reaction and may occur in association with several systemic diseases or drug therapies, or it may be idiopathic. The inflammatory reaction occurs in the panniculus.
Erythema nodosum probably is a delayed hypersensitivity reaction to a variety of antigens; circulating immune complexes have not been found in idiopathic or uncomplicated cases but may be demonstrated in patients with inflammatory bowel disease.
Peak incidence occurs at age 18-34 years. Age and sex distributions vary according to etiology and geographic location.
Rates of erythema nodosum vary according to country. In England, the rate is 2.4 cases per 10,000 per year.
Women are affected more often than men, with a male-to-female ratio of 1:4.
Erythema nodosum may occur in children and in patients older than 70 years, but it is more common in young adults aged 18-34 years. Age distribution varies with geographic location and etiology.
Nguyen GC, Torres EA, Regueiro M, et al. Inflammatory bowel disease characteristics among African Americans, Hispanics, and non-Hispanic Whites: characterization of a large North American cohort. Am J Gastroenterol. 2006 May. 101(5):1012-23. [Medline].
Mert A, Ozaras R, Tabak F, Pekmezci S, Demirkesen C, Ozturk R. Erythema nodosum: an experience of 10 years. Scand J Infect Dis. 2004. 36(6-7):424-7. [Medline].
Psychos DN, Voulgari PV, Skopouli FN, Drosos AA, Moutsopoulos HM. Erythema nodosum: the underlying conditions. Clin Rheumatol. 2000. 19(3):212-6. [Medline].
Mert A, Ozaras R, Tabak F, Ozturk R. Primary tuberculosis cases presenting with erythema nodosum. J Dermatol. 2004 Jan. 31(1):66-8. [Medline].
Kakourou T, Drosatou P, Psychou F, Aroni K, Nicolaidou P. Erythema nodosum in children: a prospective study. J Am Acad Dermatol. 2001 Jan. 44(1):17-21. [Medline].
Requena L, Yus ES. Erythema nodosum. Dermatol Clin. 2008 Oct. 26(4):425-38, v. [Medline].
Bottone EJ. Yersinia enterocolitica: the charisma continues. Clin Microbiol Rev. 1997 Apr. 10(2):257-76. [Medline].
Polcari IC, Stein SL. Panniculitis in childhood. Dermatol Ther. 2010 Jul-Aug. 23(4):356-67. [Medline].
García-Porrúa C, González-Gay MA, Vázquez-Caruncho M, López-Lazaro L, Lueiro M, Fernández ML, et al. Erythema nodosum: etiologic and predictive factors in a defined population. Arthritis Rheum. 2000 Mar. 43(3):584-92. [Medline].
Farhi D, Cosnes J, Zizi N, et al. Significance of erythema nodosum and pyoderma gangrenosum in inflammatory bowel diseases: a cohort study of 2402 patients. Medicine (Baltimore). 2008 Sep. 87(5):281-93. [Medline].
Sullivan R, Clowers-Webb H, Davis MD. Erythema nodosum: a presenting sign of acute myelogenous leukemia. Cutis. 2005 Aug. 76(2):114-6. [Medline].
Wanat KA, Rosenbach M. Cutaneous Sarcoidosis. Clin Chest Med. 2015 Dec. 36 (4):685-702. [Medline].
Grunewald J, Eklund A. Lofgren's syndrome: human leukocyte antigen strongly influences the disease course. Am J Respir Crit Care Med. 2009 Feb 15. 179(4):307-12. [Medline].
Moraes AJ, Soares PM, Zapata AL, Lotito AP, Sallum AM, Silva CA. Panniculitis in childhood and adolescence. Pediatr Int. 2006 Feb. 48(1):48-53. [Medline].
Requena L, Yus ES. Panniculitis. Part I. Mostly septal panniculitis. J Am Acad Dermatol. 2001 Aug. 45(2):163-83; quiz 184-6. [Medline].
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. [Medline].
Gilchrist H, Patterson JW. Erythema nodosum and erythema induratum (nodular vasculitis): diagnosis and management. Dermatol Ther. 2010 Jul-Aug. 23(4):320-7. [Medline].