How is morphology of erythema multiforme?

➢ Affected individuals present with a wide array of lesions, which may include macules, papules, vesicles, and bullae (hence the term multiforme). ➢ Well-developed lesions have a characteristic “targetoid” appearance, Target like lesions consist of a pale central blister or zone of epidermal necrosis surrounded by macular erythema. ➢ Early lesions show ✓ a superficial perivascular lymphocytic infiltrate ✓ dermal edema ✓ margination of lymphocytes along the dermoepidermal junction in intimate association with apoptotic keratinocytes ➢ With time, discrete, confluent zones of basal epidermal necrosis appear, with concomitant blister formation. In a rarer and more severe form of this disease, toxic epidermal necrolysis, the necrosis extends through the full thickness of the epidermis