• Female > male
• Mortality rate:
  • SJS: 1-5% 
  • TEN: 25-35% 

Risk factors:

• Slow acetylators
• Immunocompromised patients (patients with AIDS are 1000 times more likely to develop TEN)
• Radiotherapy concomitant with anticonvulsants treatment
• Specific human leukocyte antigen (HLA) alleles:
  • HLA-B*15:02 – Asians and East Indians and carbamazepine 
  • HLA-B*58:01 – Han Chinese and allopurinol
  • HLA-B*15:02 – Han Chinese and lamotrigine
  • HLA-B*15:02 – Han Chinese and phenytoin
  • HLA-A*31:01– Europeans and carbamazepine