After these initial prodromal symptoms comes the exanthem phase, which is where a red, blotchy, maculopapular rash spreads in a cephalocaudal progression.

在这些初期症状之后是皮疹期，即发红的斑状丘疹在头颈部扩散。

In other words, the exanthem starts at the head (or cephalo), and spreads to the extremities or ends of the body (or caudal).

换言之，疹开始于脑干（或头颅）并扩散到肢体或身体末端。

In general, infected people are most contagious starting from the final day of the incubation period through the prodromal and exanthem phase, which roughly works out to be 4 days before to 4 days after the onset of the rash.

一般来说，感染者极具传染性，从潜伏期的最后一天开始，经过前驱期和皮疹期，大约是从出疹前4天到后4天为止。