Itchy red bumps on chest area, 3 days now, spreading, possible bug bites

[Asley369]

I am currently in Indonesia, and have itchy red bumps that started around my chest a few days ago and have already to abdomen. Itchy throughout the day, have used topical Benadryl cream, seems to help but still spread. In shared accommodation at the moment where noone else has experienced symptoms. Slept in a new bed last night and fresh sheets so could rule out bed bugs, and only seems to affect one area. I have photos but not sure how to attach, and ideas would be helpful. They are red, realtively small, no head in clusters but also spread out.