Iris lesion is seen in

Erythema multiforme(EM) is an acute ,self limiting skin disease charecterised by the abrupt onset of symmetrical target lesions. Erythema multiforme is a skin reaction that can be triggered by an infection or some medicines. The classic lesions are iris or target lesions which are less than 3 cm in diameter, rounded and have 3 zones:central area of dusky erythema, middle paler area of oedema and an outer ring of erythema with well defined margin. Sites: commonly the extremities and the face, but face,trunk ,oral and genital mucosa may be affected. There are two forms: EM major and EM minor. Ref Harrison 20th edition pg 1235, Fitzpatrick 8thednpg 434)