Erythema Multiforme Differential Diagnoses

Updated: Feb 20, 2020
  • Author: Jose A Plaza, MD; Chief Editor: William D James, MD  more...
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Diagnostic Considerations

Although erythema multiforme (EM) is uncommon, the potentially life-threatening nature of the major form of the illness requires that clinicians maintain a high index of clinical awareness. Early diagnosis and aggressive supportive care are the essential elements of care in such severe cases.

Report any suspected erythema multiforme adverse drug reactions to the manufacturer and the appropriate regulatory authorities. Only in this manner can problematic drugs be identified, relabeled, or possibly even withdrawn from the market.

Conditions that should also be considered when evaluating a patient with suspected erythema multiforme include the following:

  • Herpes simplex virus (HSV) infection

  • Mycoplasma pneumoniae infection

  • Acute generalized exanthematous pustulosis

  • Chemical burns, thermal burns

  • Collagen vascular diseases

  • Disseminated lesions of contact dermatitis, exfoliative dermatitis

  • Erythroderma

  • Figurate erythema

  • Granuloma annulare

  • Immunoglobulin A (IgA) linear dermatosis

  • Lichen planus

  • Lupus erythematosus [28]

  • Lyme disease

  • Major oral aphthae, recurrent aphthous ulcers

  • Meningococcemia

  • Mucocutaneous lymph node syndrome

  • Necrotizing vasculitis

  • Pityriasis rosea

  • Secondary syphilis

  • Septicemia

  • Serum sickness

  • Urticaria

  • Viral exanthems

Differential Diagnoses