<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 13-year-old boy re-presents to his pediatrician with a new onset rash that began a few days after his initial visit. He initially presented with complaints of sore throat but was found to have a negative strep test. His mother demanded that he be placed on antibiotics, but this was refused by his pediatrician. The boys father, a neurologist, therefore, started him on penicillin. Shortly after starting the drug, the boy developed a fever and a rash. The patient is admitted and his symptoms worsen. His skin begins to slough off, and the rash covers over 30 of his body. His oropharynx and corneal membranes are also affected. You examine him at the bedside and note a positive Nikolskys sign. What is the most likely diagnosis?? A: Erythema Multiforme, B: Stevens-Johnson Syndrome, C: Toxic Epidermal Necrolysis, D: Rocky Mounted Spotted Fever, E: Pemphigus Vulgaris,  <response>: This is a clinical case about a 13-year-old boy who developed a rash and fever after starting penicillin. The rash progressed to involve a large area of his body and caused skin sloughing and mucosal involvement. He has a positive Nikolskys sign on exam. The timeline of events points towards a drug reaction as the cause - the rash started after initiating penicillin. The extent of rash and skinmucosal involvement narrows the diagnosis to Stevens-Johnson syndrome or toxic epidermal necrolysis. These two entities fall on a spectrum of severe drug reactions that have overlapping features. The positive Nikolskys sign separation of epidermis with light touch is classic for these diagnoses. The other choices can be ruled out. Erythema multiforme has targetoid lesions rather than extensive epidermal detachment. Pemphigus vulgaris involves blistering but not full thickness epidermal necrosis. Rocky Mountain spotted fever would not develop right after taking an antibiotic.C: Toxic Epidermal Necrolysis 