This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General Considerations - Infectious Diseases, Subject name: Pediatrics
[{'content': "A girl child is suffering from varicella. And child's aunt is pregnant. When is it earliest that the child can meet her aunt? \nSelect and explain. \nA. When the lesions have crusted, B. Immediately, C. Anytime as the child is aunt's favorite, D. After the delivery of the baby", 'role': 'user'}, {'content': "Answer: A \nExplanation: a. When the lesions have crusted(Ref: Nelson's 20/e p 1579-1585, Ghai 8/e p 214-215, CDC website)The period of communicability of varicella begins 1-2 days before the onset of rash and ends when all lesions are crusted, typically 4-7 days after onset of rash in immunocompetent people, longer in immunocompromised peoplePeople with varicella should be isolated until the lesions crust over.", 'role': 'assistant'}]