Hi,
How are you? Recurring skin bumps could be caused by irritation, insect bite, infection and skin conditions such as dermatitis. If pus is present, an infection is likely and warrants further evaluation. Antibiotic treatment may be indicated. Take care and do keep us posted.
It could be a Staph infection perhaps impetigo. Do they get crusty after they pop? Try topical antibiotics such as neosporin see if they go away. Don't scratch or pick at them it will spread them. Where are they located?
mkh9