What is the treatment for Erythema multiforme?

Treatment of Erythema Multiforme

The treatment of erythema multiforme primarily involves identifying and removing the underlying cause, followed by symptomatic management with topical corticosteroids for mild cases and systemic corticosteroids for severe cases with extensive involvement. 1, 2

Etiology Assessment and Removal

• Identify and address potential triggers:
  • Herpes simplex virus (most common infectious cause)
  • Mycoplasma pneumoniae infection
  • Medications (discontinue suspected causative drugs)
  • Other infections
  • Rarely: immunizations or autoimmune diseases

Treatment Algorithm Based on Severity

Mild EM (Limited Cutaneous Involvement)

1. First-line therapy:

   • Topical moderate to high-potency corticosteroids (e.g., mometasone furoate 0.1% or betamethasone valerate 0.1% ointment) 3
   • Symptomatic relief with oral antihistamines:
     • Non-sedating (daytime): loratadine 10 mg daily or cetirizine 10 mg daily
     • Sedating (nighttime): diphenhydramine 25-50 mg or hydroxyzine 25-50 mg 3

2. Supportive care:

   • Keep affected areas cool, clean, and dry
   • Avoid friction by wearing loose-fitting, lightweight cotton clothing
   • Apply cool compresses for symptomatic relief

Moderate to Severe EM (Extensive Cutaneous or Mucosal Involvement)

1. Systemic corticosteroids:

   • Prednisone 0.5-1 mg/kg/day for 7-10 days with tapering over 1-2 weeks 4, 2
   • FDA-approved for severe erythema multiforme (Stevens-Johnson syndrome) 4

2. For mucosal involvement:

   • Topical anesthetic solutions for pain relief
   • Antiseptic mouthwashes for oral lesions
   • Artificial tears and lubricants for ocular involvement
   • Maintain adequate hydration and nutrition

3. For severe cases with extensive mucosal involvement:

   • Consider hospitalization for IV fluids and electrolyte management 1
   • Pain management as needed

Management of Recurrent EM

1. For HSV-associated recurrent EM:

   • Antiviral prophylaxis is the mainstay of treatment 1, 2
   • Options include:
     • Acyclovir 400 mg twice daily
     • Valacyclovir 500 mg daily
     • Continue for 6-12 months, then reassess

2. For idiopathic recurrent EM resistant to first-line therapies:

   • Consider immunosuppressive agents:
     • Azathioprine
     • Mycophenolate mofetil
     • Dapsone
   • Antimalarials or antibiotics may be considered in select cases 2

Special Considerations

• Differentiate from Stevens-Johnson Syndrome (SJS): EM typically presents with target-like lesions on extremities with centripetal spread, while SJS presents with widespread erythematous or purpuric macules with blisters and more severe mucosal involvement 5, 1

• Monitor for complications: Secondary bacterial infections, dehydration, and electrolyte imbalances, especially with extensive mucosal involvement 3

• Duration of therapy: Individual EM lesions typically persist for at least 7 days (unlike urticaria which resolves within 24 hours) 1

• Follow-up: Reassess after 1-2 weeks of treatment; if no improvement or worsening occurs, consider dermatology referral 3

The management approach should be adjusted based on clinical response, with careful attention to identifying and addressing the underlying cause to prevent recurrence.