A 60-year old patient presented with several bullous lesions for the last 3 days; each bulk was surrounded by an erythematous halo. There were multiple target lesions. The patient also had oral erosions. The most likely diagnosis is –

This patient has :- i) Target lesion ii) Mucosal involvement (oral erosion) It has already been explained that erythema multiforme syndrome has two subtypes - Erythema multiform Steven - Johnson syndrome - toxic epidermal necrolysis complex (SJS - TEN complex) Mucosal involvement (oral lesions) is common in SJS - TEN complex, whereas it is uncommon in erythema multiforme (in less than 20% of patients). So, amongst the given options answer is Steven - Johnson syndrome.