How to I monitor and prevent erythema multiforme (EM)

Condition analysis:
Erythema Multiforme (EM) is an acute, self-limited, and sometimes recurring skin condition that is considered to be a type IV hypersensitivity reaction associated with certain infections, medications, and other various triggers.

Erythema multiforme may be present within a wide spectrum of severity. Erythema multiforme minor represents a localized eruption of the skin with minimal or no mucosal involvement. The papules evolve into pathognomonic target or iris lesions that appear within a 72-hour period and begin on the extremities (see the following image). Lesions remain in a fixed location for at least 7 days and then begin to heal. An arcuate appearance may be present (see the second image below). Precipitating factors include herpes simplex virus (HSV), Epstein-Barr virus (EBV), and histoplasmosis. Because this condition may be related to recurrent HSV, recurrences of erythema multiforme may follow, with many affected individuals experiencing several recurrences per year.

Instructions:
Monitoring and Prevention
The medical professional(s) who treated the patient if he or she was hospitalized should see the patient regularly and provide symptomatic relief, as needed. Such practitioners may include burn or trauma surgeons, ophthalmologists, nephrologists, infectious disease specialists, and gastroenterologists.

The affected skin should be protected from any pressure or shear forces. Otherwise, early institution of physical and occupational therapies is appropriate. To reduce the likelihood of developing hyperpigmentation, recommend the use of sunscreens for 1 year after the incident has resolved.
Once erythema multiforme (EM) due to a drug has been diagnosed, the patient should never be rechallenged with the same drug or any other drug of the same class or similar chemical structure. Chemically related compounds often share a common metabolic pathway that may be abnormal in the affected individual. Sulfonamide-containing ointments should also be avoided.

First-degree relatives of an affected patient have an increased risk of reactions to similar drugs.