Q. A 10-year-old boy is brought to the emergency department for fever and skin rash for the past 3 days. He initially had a fever for which his mother has given him fever-reducer syrup, but since last night he has developed a diffuse body rash which is extremely painful and itchy. He also has burning eyes, photophobia, and painful swallowing. His medical history shows that he was diagnosed with generalized tonic-clonic seizures and has been using carbamazepine for the last 2 years. But as his seizures were not under full control, lamotrigine has been recently added a month ago. His temperature is 101.5°F (38.6°C), pulse is 100/min, blood pressure is 80/60 mmHg, and respirations are 15/min. Physical examination shows a toxic-appearing boy crying with pain. He has a diffuse tender erythematous macular rash with some vesicles and bullae all over the body except the scalp, palms, and soles. His eyes are congested with purulent discharge. Oral examination shows bleeding ulcers with grayish membranes. Laboratory evaluation is shown below. What is the most likely diagnosis for this patient based on his clinical features?