red bump

I noticed a bump under his skin, then red spots which I chalked up to him and his brother playing roughly. Now they have a white scabby layer on them. Anyone know what this is or how to fix it?thank you!!

Noticed this on our Luna. At first I thought it was a food stain at quick glance. She is not in pain nor does she pick, scratch or lick it. It’s allergy season here in Phoenix AZ and scorpions are also starting to appear. Should I be worried? Thank you!