What causes a swollen pimple on right side of abdomen?

"Swollen pimple" If a little red raised bump on your body you initially thought was a pimple starts to swell, it may be a signs of an infection, especially if there is associated redness & tenderness. These may progress to more advanced infections. After you are examined, your doctor will be able to decide on specific treatments, such as antibiotics or incision & drainage. These are easier to treat if done soon.