Drug-induced Lyell and Stevens-Johnson syndromes.

1) Lyell syndrome is characterised by toxic epidermal necrolysis in which epidermal detachment affects more than 30% of the body surface area. Stevens-Johnson syndrome is a minor form affecting less than 10% of the body surface area; 2) Patients who present with these cutaneous symptoms, along with throat pain, red eyes and a damaged or detached oral mucosa must be hospitalised immediately; 3) Lyell syndrome is exclusively caused by drugs while Stevens-Johnson syndrome can also be caused by bacteria and viruses. Rapid withdrawal of the drug improves prognosis.