Brief Answer:
Findings seem to be consistent with drug reaction
Detailed Answer:
Hi,
Thanks for writing to us.
From the description provided, it seems the hospitalised person has developed a drug reaction. It could be Stevens XXXXXXX syndrome, if body area involved is less than 10 percent or 
toxic epidermal necrolysis, if body area involved is more than 30 percent. Another possibility could be 
erythema multiforme that usually has similar picture but occurs due to an underlying infection( most commonly 
herpes simplex virus infection).
Drug reactions are basically 
hypersensitivity reactions and should be managed actively as it could be fatal too if body involvement is extensive. In drug reactions, the offending drug should be stopped immediately and should never be taken again as it can again cause a severe reaction.
In our clinical setup we usually manage it with a  dose of intravenous 
steroid like 
hydrocortisone started in a high dose and tapered in few days. This controls the disease activity( however some consider its use to be questionable). Also patient should be kept under antibiotic coverage to prevent infection of peeling skin. Intravenous fluid line should also be started to maintain adequate hydration and nutrition. Topically, antibiotic cream should be applied to help the lesions heal and patient should be kept in an isolated and sterile room to prevent any infection. 
Hope this helped. Should there be any other doubt,please write back.
Wishing the young girl a speedy recovery.