What’s this on my toddlers arm?

Kaitlyn

He’s had these for a while now and today they started bothering him ( they itched for a few minutes then the itch went away) he has 3 now and has never had them before I’ve given him Claritin for his allergies hoping it’ll do something but they won’t go away…. He is sick right now with a bad cough and off and on fever ranging from 100.9- 102 I don’t know what to do