Background: Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare, but potentially life-threatening reactions to medications. Both conditions have significant morbidity and mortality. This study aimed to document the epidemiological features, aetiologies, treatment and clinical outcomes of such patients.Method: In this retrospective cross-sectional study the records of all patients with TEN treated for5 years in central Hospital, Mashhad, Iran were reviewed. Results: Thirty-four patients were studied with a mean age of 26.5 years. Mean age in the mortality and survivors groups was 33.6 and 25.3 years, respectively. Drugs accounted for all 34 cases were including Anti-convulsants (52.9%) other the most common implicated drug followed by antibiotics (26.5%), allopurinol (5.9%) and multiple drugs (anticonvulsants plus antibiotics) (14.7%). Antibiotics had the shortest interval between ingestion time and onset of symptoms. The mean ICU length of stay was 12.7 days, with a range of 1 to 30 days. The mean of SCORTEN was 2.3; it was 3.3 and 2.1 in the mortality and survivors group, respectively (P=0.001).All 34 TEN cases were given intravenous immunoglobulins (IVIG). Six patients with TEN died (17.6%). The highest mortality was found in the allopurinol group with 50%, whereas anticonvulsants and antibiotics had a mortality rate of 16.6% and 15.3%, respectively.Conclusion: Anti-convulsants especially Lamotrigine were the most frequently implicated drug, followed by antibiotics and allopurinol. IVIG was shown beneficial effects in TEN syndrome
