If you have a condition called solar urticaria, big, itchy welts develop within minutes of sun exposure.

如果您患有日光性荨麻疹，暴露在阳光下几分钟内就会出现又大又痒的伤痕。

In solar urticaria, that same process seems to happen, but the molecule that’s causing the immune system freakout is a mystery.

在日光性荨麻疹中，似乎会发生同样的过程，但导致免疫系统崩溃的分子是一个谜。

Instead of showing up almost immediately, like solar urticaria, it can take hours or even days and it sticks around for a while, too.

它不会像日光性荨麻疹那样几乎立即出现，而是可能需要数小时甚至数天， 并且还会持续一段时间。