One to three days before a rash develops, you may show early signs of Stevens-Johnson syndrome, including: 
Fever
A sore mouth and throat
Fatigue
Burning eyes
 As the condition develops, other signs and symptoms include: 
Unexplained widespread skin pain
A red or purple rash that spreads
Blisters on your skin and the mucous membranes of the mouth, nose, eyes and genitals
Shedding of skin within days after blisters form
