What is the difference between stephen johnson diease and and the syndrome i can't find anything about the diease which i was diagnosed with?

Erythema Multiforme: Erythema Multiforme (EM minor) is a type of allergic reaction that occurs via a distinct and separate mechanism from immediate hypersensitivity reactions (hives). The rash is longer lasting, and generally does not respond to antihistamines. A more severe version called Stevens-Johnson Syndrome (aka EM major) also affects mucous membranes (eyes, mouth, genitals) and requires immediate assessment.