What is the treatment for erythema nodosum leprosum?

Treatment of Erythema Nodosum Leprosum

For erythema nodosum leprosum (ENL), oral prednisolone at 0.5-1 mg/kg daily is the first-line treatment, with thalidomide reserved for chronic/recurrent cases or as a steroid-sparing agent, and clofazimine used for maintenance therapy to prevent recurrences. 1, 2

First-Line Treatment

Oral corticosteroids are the primary treatment for acute ENL:

• Start prednisolone at 0.5-1 mg/kg daily 3
• For cases not responding to once-daily dosing, consider split-dose regimen (dividing the same total daily dose into multiple administrations) which provides better control without increasing total steroid burden 3
• Taper gradually according to WHO protocol once initial control is achieved 4

Second-Line and Steroid-Sparing Agents

When corticosteroids alone are insufficient or patients become steroid-dependent:

Thalidomide is highly effective:

• Demonstrated significant benefit compared to aspirin (RR 2.43; 95% CI 1.28 to 4.59) 2
• Combined with prednisolone, achieves 80% non-recurrence rate versus 66% with clofazimine 5
• Provides superior reduction in reaction severity scores and pain compared to clofazimine combinations 5
• Critical caveat: Teratogenicity risk requires strict contraception protocols and is contraindicated in pregnancy 6
• Peripheral neuropathy can be permanent 6

Clofazimine for chronic/recurrent ENL:

• Dose: 100 mg three times daily 4
• Superior to prednisolone for treatment success (RR 3.67; 95% CI 1.36 to 9.91) 2
• Fewer recurrences compared to thalidomide alone (RR 0.08; 95% CI 0.01 to 0.56) 2
• Main adverse effects: skin pigmentation (reversible) and QTc prolongation requiring monthly ECG monitoring 6
• Takes longer to achieve initial control (4 weeks) compared to minocycline (3 weeks) 4

Minocycline is an emerging option:

• Dose: 100 mg once daily for 12 weeks 4
• Achieves faster initial control than clofazimine (2.97 vs 4 weeks, p=0.048) 4
• Longer remission duration after initial control (p=0.001) 4
• Fewer adverse events than clofazimine (p=0.047) 4

Refractory Cases

For severe ENL failing conventional therapy:

TNF-α inhibitors (etanercept, infliximab):

• Reserved for cases refractory to corticosteroids, thalidomide, and clofazimine 1, 7
• Case reports demonstrate complete resolution in patients failing 6+ years of conventional therapy 7
• Rationale: TNF-α plays key role in ENL pathophysiology 1

Other options for resistant cases include:

• Cyclosporine A 1
• Pentoxifylline 2
• Intravenous immunoglobulin (IVIG) 1
• Plasma exchange 1

Treatment Algorithm

1. Acute ENL: Start prednisolone 0.5-1 mg/kg daily; if inadequate response, use split-dose regimen 3

2. Chronic/recurrent ENL or steroid-dependent: Add thalidomide (if no contraindications) OR minocycline 100 mg daily 4, 5

3. Maintenance/prevention of recurrence: Clofazimine 100 mg three times daily for 12 weeks minimum 2, 4

4. Refractory to above: Consider TNF-α inhibitors (etanercept or infliximab) 1, 7

Critical Monitoring

• With clofazimine: Monthly ECG for QTc prolongation, especially with other QTc-prolonging agents 6
• With thalidomide: Strict pregnancy prevention, monitor for peripheral neuropathy 6
• With split-dose prednisolone: Monitor for HPA axis suppression, though studies show this approach does not cause suppression 3