Cаrsоn, а 10-yeаr-оld is brоught to the primary care clinic for a rash that is all over her skin. According to her mother, she suffered symptoms of fever, malaise, sore throat, headache, and loss of appetite for a few days, and then as her symptoms improved, she started exhibiting a rash. The rash began a day after her initial symptoms and started with oral-cavity blisters. Over the last few days, the rash has progressed to small red dots on the face and scalp and spread quickly to her torso and limbs within a day. There are now blisters and pustules that accompany the initial papules seen. Carson's temperature= 100.2 degrees F, HR= 90, RR= 20, BP= 110/80. The child is on a modified vaccine schedule (per family choice) and has only received DtaP, Hepatitis B, HIB, and Pneumococcal vaccines. Physical exam reveals approximately 300 macules, pustules, and blisters all over her body (including pharynx vagina, and anus in different stages (see photo below). What is the most likely diagnosis?