What is the best management approach for erythema multiforme?

Management of Erythema Multiforme

The best management approach for erythema multiforme involves identifying and treating the underlying cause while providing appropriate symptomatic relief, with systemic corticosteroids reserved for severe cases.

Etiology Identification and Elimination

1. Identify and eliminate potential triggers:
   • Discontinue any potential culprit medications immediately 1
   • Evaluate for herpes simplex virus (HSV) infection - the most common infectious trigger 2, 3
   • Test for Mycoplasma pneumoniae, especially in children 3
   • Document all medicines taken over the previous 2 months, including over-the-counter and complementary therapies 1

Clinical Assessment

• Differentiate erythema multiforme (EM) from Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN):
  • EM typically presents with target-like lesions symmetrically on extremities (especially extensor surfaces) 3
  • EM lesions are fixed for at least 7 days (unlike urticaria which resolves within 24 hours) 3
  • SJS/TEN presents with widespread erythematous or purpuric macules with blisters 3
  • Document the extent of erythema and epidermal detachment separately 1

Management Algorithm

Mild Cutaneous EM (without significant mucosal involvement)

1. Symptomatic treatment:
   • Topical corticosteroids for skin lesions 2, 3
   • Oral antihistamines for pruritus 2, 3
   • Adequate hydration and supportive care 4

EM with Mucosal Involvement

1. Oral mucosal lesions:

   • Antiseptic or anesthetic solutions 2
   • Topical corticosteroids 2
   • Aluminum hydroxide/magnesium hydroxide/simethicone mouthwash for comfort 5

2. Ocular involvement:

   • Ophthalmology consultation for specialized management 5
   • Monitor for long-term sequelae including trichiasis, symblepharon, and punctal stenosis 5

3. Genital/urethral involvement:

   • Topical 2% lidocaine gel for urinary discomfort 5

Severe EM (Erythema Multiforme Major)

1. Consider hospitalization for:

   • Severe mucosal involvement causing poor oral intake 3, 6
   • Fluid and electrolyte imbalance 3
   • Need for pain management with opioids 5

2. Systemic therapy:

   • Systemic corticosteroids (prednisone) for severe cases 7, 2
   • Prednisone is FDA-approved for severe erythema multiforme (Stevens-Johnson syndrome) 7
   • Intravenous fluids for hydration as needed 3

Recurrent EM (particularly HSV-associated)

1. First-line treatment:

   • Antiviral prophylaxis (acyclovir, valacyclovir) 2, 3, 6
   • Continuous suppressive therapy for HSV-associated recurrent EM 6

2. Second-line options for refractory cases:

   • Immunosuppressive agents 2
   • Antimalarials 2
   • Antibiotics 2

Important Considerations

• Avoid potential irritants on affected skin areas:

  • Greasy creams (may facilitate folliculitis) 1
  • Manipulation of skin (risk of infection) 1
  • Topical acne medications (may irritate and worsen condition) 1

• Monitor for complications:

  • Secondary bacterial infections requiring antibiotics 1
  • Dehydration from reduced oral intake 3
  • Long-term ocular sequelae requiring ophthalmologic follow-up 5

• For children with EM:

  • Recurrence is more common (up to 18% of cases) 1
  • Infection is more commonly the precipitant than drugs 1
  • Mortality appears lower than in adults 1

By following this management approach, most cases of erythema multiforme will resolve without significant complications, though recurrent cases may require long-term prophylactic therapy.