We report the case of a 16-month-old boy weighing 11 kg who presented toxic epidermal necrolysis secondary to phenobarbital administration and underwent emergency laparotomy under general anesthesia because of gastrointestinal bleeding. The boy presented epidermal detachment on the slightest friction (Nikolsky's sign) so monitoring was difficult; in these cases it is advisable to use padded sphygmomanometers and weighted electrodes. Owing to the great extension of denuded skin, these patients must be considered as hypovolemic and ketamine is the drug of choice for anesthesia induction. The maintenance of airways and the proper replacement of fluids and electrolytes are essential for the correct anesthetic treatment of these patients.