Bedbugs still exist on the Camino. In some albergues (mainly in the older ones) bedbugs can cause problems. They live in the mattresses and active during the night. Some pilgrims (not many) can be inflicted by them. This practically means that bites appear on the whole body and you have more in each hour.
Bedbug rashes are allergic reactions and may take up to a week to manifest, one of the reasons it is hard to pinpoint where one was bitten. The rashes take a while to go away but go to the pharmacy and get some lotion and some oral antihistamine to ease the itch. You must spray everything with bug spray, your backpack, your sleeping bag, your clothes, and wash them all, including the ones you wear.
Don’t forget to spray your shoes as well. The bugs can hide in every tiny seam and crevasse.