A 7-year-old unvaccinated child presents with a fever and a rash characterized by itchy, fluid-filled blisters that started on the chest and spread to the face and extremities. What is the most likely diagnosis and the next step?
This presentation is typical of chickenpox (varicella), a highly contagious disease caused by the varicella-zoster virus. The next step is to advise rest, hydration, and over-the-counter remedies for itchiness such as calamine lotion. Antipyretics can be used to manage fever. Isolation from non-immune individuals is crucial to prevent the spread of the disease.