Erythema Nodosum: A Practical Approach and Diagnostic Algorithm

Daniela Michelle Pérez-Garza; Sonia Chavez-Alvarez; Jorge Ocampo-Candiani; Minerva Gomez-Flores


Am J Clin Dermatol. 2021;22(3):367-378. 

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Therapy options are summarized in Table 4. Symptomatic support is an adequate approach for most patients. Compression bandages and limb elevation may be used for edema and pain relief.[67] Non-steroidal anti-inflammatory drugs, such as indomethacin at 100–150 mg/day or naproxen 500 mg/day, may be used for pain control.[68,69] Caution should be taken with the use of non-steroidal anti-inflammatory drugs in patients with IBD as these drugs may worsen IBD symptoms.[70]

In refractory disease, oral potassium iodide may be used with a dose of 300–900 mg daily divided into three doses and tapered to 150 mg/day.[71,72] Although it has been used for a long time with a good response rate,[73,74] a recent study showed low improvement and suggested that its potential efficacy in inflammatory skin disorders is overestimated.[72] The exact mechanism by which potassium iodide exerts its anti-inflammatory effect is unknown. The anti-inflammatory effects are due to increases in IL-10 and IL-35 levels[75] and the suppression of chemotaxis in neutrophils and their capability to generate toxic radicals.[76] Common acute side effects are diarrhea, nausea, vomiting, and stomach pain. Symptoms of iodism or potassium toxicity may appear with prolonged use. It is contraindicated during pregnancy or while breastfeeding.[77]

Colchicine at 1–2 mg/day, adjusted to body weight, has been used mainly in patients with EN and Behçet disease.[78–80] It decreases neutrophil chemotaxis and degranulation. Common side effects are gastrointestinal symptoms (diarrhea, abdominal pain, and nausea).[81]

Dapsone inhibits neutrophil myeloperoxidase and neutrophil chemotaxis. Doses of 50–75 mg/day have been used with caution because of its potential side effects, including methemoglobinemia, hemolysis, agranulocytosis, and peripheral motor neuropathy.[82] Potassium iodide, colchicine, and dapsone are drugs used for treating neutrophilic dermatosis, making them a good option for EN associated with Bechet disease.

Systemic and intralesional corticosteroids are rarely used to treat EN. Prednisone 40 mg/day has been used in severe conditions. For recalcitrant nodules, intralesional triamcinolone acetonide 5 mg/mL, injected to the center of an inflamed lesion, has been used. An underlying infection or malignancy should be ruled out before using corticosteroids.[10]

Some patients respond to hydroxychloroquine 200 mg twice daily.[83,84] Tetracyclines, such as minocycline 100 mg twice daily and tetracycline 500 mg every 6–12 h, have been considered as an option for chronic EN.[85,86] Tumor necrosis factor-α inhibitors such as etanercept,[87,88] adalimumab,[89,90] and infliximab[91,92] have been used in patients with recalcitrant disease. Thalidomide and cyclosporine A have been used in EN associated with IBD.[9,28]