Thalidomide
Thalidomide has been used to relieve painful lesions but its use may be limited by its teratogenicity.[29]Van Veen NH, Lockwood DN, van Brakel WH, et al. Interventions for erythema nodosum leprosum. Cochrane Database Syst Rev. 2009 Jul 8;(3):CD006949.
http://onlinelibrary.wiley.com/doi/10.1002/14651858.CD006949.pub2/full
http://www.ncbi.nlm.nih.gov/pubmed/19588412?tool=bestpractice.com
[30]Kaur I, Dogra S, Narang T, et al. Comparative efficacy of thalidomide and prednisolone in the treatment of moderate to severe erythema nodosum leprosum: a randomized study. Australas J Dermatol. 2009 Aug;50(3):181-5.
https://www.doi.org/10.1111/j.1440-0960.2009.00534.x
http://www.ncbi.nlm.nih.gov/pubmed/19659979?tool=bestpractice.com
Azathioprine
Azathioprine is an immunosuppressive drug that has had anecdotal success in treating erythema nodosum.[31]Verma KK, Srivastava P, Minza A, et al. Role of azathioprine in preventing recurrences in a patient of recurrent erythema nodosum leprosum. Lepr Rev. 2006 Sep;77(3):225-9.
http://www.ncbi.nlm.nih.gov/pubmed/17172003?tool=bestpractice.com
Thiopurine methyltransferase levels should be checked prior to initiating use, and regular monitoring of liver blood tests and full blood count are required for the duration of therapy. Patients unable to comply with regular follow-up and testing should not be given this drug.[32]Meggitt SJ, Anstey AV, Mohd Mustapa MF, et al. British Association of Dermatologists' guidelines for the safe and effective prescribing of azathioprine 2011. Br J Dermatol. 2011 Oct;165(4):711-34.
http://www.bad.org.uk/healthcare-professionals/clinical-standards/clinical-guidelines
http://www.ncbi.nlm.nih.gov/pubmed/21950502?tool=bestpractice.com
Colchicine
A widely used treatment for Behçet's syndrome, colchicine is an anti-inflammatory agent shown to be effective in controlling erythema nodosum.[33]Yurdakul S, Mat C, Tüzün Y, et al. A double-blind trial of colchicine in Behçet's syndrome. Arthritis Rheum. 2001 Nov;44(11):2686-92.
https://www.doi.org/10.1002/1529-0131(200111)44:11<2686::aid-art448>3.0.co;2-h
http://www.ncbi.nlm.nih.gov/pubmed/11710724?tool=bestpractice.com
[34]McEwan T, Robinson PC. A systematic review of the infectious complications of colchicine and the use of colchicine to treat infections. Semin Arthritis Rheum. 2021 Feb;51(1):101-12.
https://www.doi.org/10.1016/j.semarthrit.2020.11.007
http://www.ncbi.nlm.nih.gov/pubmed/33360321?tool=bestpractice.com
Common side effects include gastrointestinal symptoms such as diarrhoea, abdominal pain, and nausea; caution should be taken when prescribing colchicine in patients with comorbidities.[35]Stewart S, Yang KCK, Atkins K, et al. Adverse events during oral colchicine use: a systematic review and meta-analysis of randomised controlled trials. Arthritis Res Ther. 2020 Feb 13;22(1):28.
https://www.doi.org/10.1186/s13075-020-2120-7
http://www.ncbi.nlm.nih.gov/pubmed/32054504?tool=bestpractice.com
Dapsone
Dapsone is an antibacterial agent with anti-inflammatory properties. It has been evaluated in the management of EN recalcitrant to standard therapies; dapsone appears to be effective in the management of mucocutaneous manifestations of Behcet's disease.[36]Song JS, Halim K, Vleugels RA, et al. Dapsone for treatment of erythema nodosum. Dermatol Online J. 2016 Feb 17;22(2):13030/qt8z782742.
http://www.ncbi.nlm.nih.gov/pubmed/27267197?tool=bestpractice.com
[37]Sharquie KE, Najim RA, Abu-Raghif AR. Dapsone in Behçet's disease: a double-blind, placebo-controlled, cross-over study. J Dermatol. 2002 May;29(5):267-79.
http://www.ncbi.nlm.nih.gov/pubmed/12081158?tool=bestpractice.com
Potential side effects include methemoglobinaemia, haemolysis, agranulocytosis, and peripheral motor neuropathy.[36]Song JS, Halim K, Vleugels RA, et al. Dapsone for treatment of erythema nodosum. Dermatol Online J. 2016 Feb 17;22(2):13030/qt8z782742.
http://www.ncbi.nlm.nih.gov/pubmed/27267197?tool=bestpractice.com
Mycophenolate
Results from case reports suggest that mycophenolate may have a role as a corticosteroid-sparing agent in patients with erythema nodosum.[38]Boyd AS. Use of mycophenolate mofetil in erythema nodosum. J Am Acad Dermatol. 2002 Dec;47(6):968-9.
http://www.ncbi.nlm.nih.gov/pubmed/12451393?tool=bestpractice.com
[39]Ying S, Li S, Tang S, et al. Immune-mediated necrotizing myopathy initially presenting as erythema nodosum. J Inflamm Res. 2020;13:471-6.
https://www.doi.org/10.2147/JIR.S270114
http://www.ncbi.nlm.nih.gov/pubmed/32922062?tool=bestpractice.com
Etanercept
The tumour necrosis factor (TNF)-alpha inhibitor etanercept has been used to treat EN successfully in several reported cases.[40]Alia E, Varma A, Brody J, et al. Use of etanercept in management of tyrosine kinase-inhibitor-induced erythema nodosum. JAAD Case Rep. 2020 Jun;6(6):567-8.
https://www.doi.org/10.1016/j.jdcr.2020.04.016
http://www.ncbi.nlm.nih.gov/pubmed/32509950?tool=bestpractice.com
[41]Boyd AS. Etanercept treatment of erythema nodosum. Skinmed. 2007 Jul-Aug;6(4):197-9.
http://www.ncbi.nlm.nih.gov/pubmed/17618179?tool=bestpractice.com
Infliximab
Infliximab is a chimeric mouse-human monoclonal antibody that specifically binds to TNF-alpha, blocking its biological activity. This consequentially restores the ability of anergic regulatory T cells to inhibit cytokine production. Four children with Crohn's disease and refractory EN who received treatment with infliximab showed a sustained response with no adverse reactions.[42]Kugathasan S, Miranda A, Nocton J, et al. Dermatologic manifestations of Crohn disease in children: response to infliximab. J Pediatr Gastroenterol Nutr. 2003 Aug;37(2):150-4.
https://www.doi.org/10.1097/00005176-200308000-00013
http://www.ncbi.nlm.nih.gov/pubmed/12883301?tool=bestpractice.com
Ciclosporin
An immunosuppressant, ciclosporin inhibits IL-2 and other cytokines. It has been used off-label for treating inflammatory skin conditions such as atopic dermatitis, blistering disorders, and connective tissue diseases.[43]Dehesa L, Abuchar A, Nuno-Gonzalez A, et al. The use of cyclosporine in dermatology. J Drugs Dermatol. 2012 Aug;11(8):979-87.
http://www.ncbi.nlm.nih.gov/pubmed/22859244?tool=bestpractice.com
Ciclosporin has been used in EN associated with inflammatory bowel disease.[44]Chavez-Álvarez S, Gómez-Flores M, Ocampo-Candiani J. [Cutaneous manifestations in inflammatory bowel disease]. [in spa]. Gac Med Mex. 2016 Sep - Oct;152(5):622-30.
http://www.anmm.org.mx/GMM/2016/n5_english/3095AX165_152_2016_UK5_557-564.pdf
http://www.ncbi.nlm.nih.gov/pubmed/27792697?tool=bestpractice.com