Picture of Erythema Multiforme 1
This disorder is termed multiforme because the morphology of its lesions is so variable. The primary lesion is most often an erythematous macule that evolves into a papule. Early in the course, these lesions may easily be mistaken for urticaria. As the lesions enlarge, they form round or irregularly shaped plaques. Concentric circles of erythema and dark gray discoloration may evolve, forming the typical “target” lesion of erythema multiforme. The “target” lesions may coalesce and develop annular or serpiginous borders. Figure 13-8 is a close-up of the target-like quality of the variably sized and shaped plaques.