A 7-year-old boy is brought to the clinic with a 2-day history of fever, fatigue, and a generalized, pruritic rash. The rash started on his trunk and quickly spread to his face and extremities. On examination, you notice macules, papules, vesicles, and crusted lesions at various stages of development. His parents report no history of varicella vaccination. Which of the following best describes the characteristic lesion of chickenpox?
