Pediatric emergency rash should actually be called acute rash in young children. This disease is an infectious skin disease caused by a viral infection, which is characterized by a persistent fever in infected children, and a rash on the head and face usually appears after 2-5 days of fever. The rash is mainly composed of large, uniform, acneiform papules, followed by rashes on the neck, trunk, and limbs, which are characterized by the same features as those of the head and face, and gradually recede in a certain order, with most of them appearing and receding in less than 3 days. This feature is a characteristic change that cannot be reproduced in other skin diseases, so it is the main feature that distinguishes it from other skin diseases.