Idiopathic Stevens-Johnson syndrome and toxic epidermal necrolysis: Prevalence and patients' characteristics

To the Editor: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are considered severe cutaneous adverse reactions to drugs. However, in some cases, no causative drug is identified. Cases of “nontoxic” SJS/TEN have been associated with Mycoplasma pneumoniae infection or connective tissue diseases or considered idiopathic.1 Very few data about idiopathic cases of SJS/TEN are available.