Carbuncles appear as red, swollen, pus-filled bumps that most commonly develop on the back of the neck, back, armpits, and buttocks. Staphylococcus aureus (staph) bacteria cause most carbuncles.

A boil starts as a red, painful bump and is usually found in the buttocks, face, neck, armpits and groin. These infections consist of a white tip, or ‘head’ form and grow in hairy areas where ...