Prevention of erythema multiforme is only possible when the cause is known. If it is caused by a medication, the medication may need to be stopped. Medications used to treat herpes, such as acyclovir or valacyclovir, may prevent recurrence if the condition is caused by a herpes outbreak. Most cases are not preventable.
Scarring or infection of the skin, vision problems, scarring in the gut, and even death may result from severe forms of erythema multiforme. Most cases do not cause any long-term effects.
Erythema multiforme is not contagious and poses no risk to others.