Despite these data, in order to avoid risks, many authors recommend avoiding the administration of cephalosporins and carbapenems to subjects with clinical history or laboratory documentation of possible IgE-mediated allergy to penicillins who have suffered from severe clinical manifestations, anaphylaxis, and Steven–Johnson syndrome, including toxic epidermal necrolysis [5,25]. Here, IGHE is linked to toxic epidermal necrolysis.