Erythema Multiforme Management
Diagnosis and Differential Diagnosis
- Erythema multiforme (EM) is distinguished from Stevens-Johnson Syndrome (SJS) by its acral distribution with target lesions and limited mucosal involvement, whereas SJS presents with widespread erythematous/purpuric macules with blisters and extensive mucosal involvement, as noted by the British Journal of Dermatology and the American Academy of Dermatology 1, 2
- Biopsy may help in unclear cases, with subepidermal cleavage characteristic of SJS/TEN, according to the British Journal of Dermatology and the American Academy of Dermatology 1, 2
- Erythromelalgia should be avoided as a misdiagnosis, as it presents with burning pain and redness in extremities and is treated differently with aspirin as first-line therapy, according to the Mayo Clinic Proceedings 3
Identifying Underlying Triggers
- Herpes simplex virus is the most common cause of EM, and other triggers include Mycoplasma pneumoniae infection, medications, and other viral infections, such as EBV, HCV, and Coxsackie, as noted by the British Journal of Dermatology 1
Treatment Approach
- The British Journal of Dermatology recommends discontinuing any potential culprit medications, such as antibiotics, anticonvulsants, and NSAIDs, which can trigger EM 1
- Topical corticosteroids are recommended as first-line therapy for cutaneous lesions, with high-potency topical corticosteroids applied to affected areas 2-3 times daily, and systemic corticosteroids may be considered for severe cases, with prednisone 40-60 mg daily for 5-7 days with taper, as suggested by the American College of Dermatology and some studies 2
- Antiviral therapy with acyclovir 400 mg three times daily for 7-10 days may be effective for HSV-associated EM, and antiviral prophylaxis with acyclovir 400 mg twice daily or valacyclovir 500 mg daily may be considered for HSV-associated recurrent EM, as suggested by some studies 2