Medically reviewed by Susan Bard, MD Boils are painful, pus-filled, and are caused by infections like Staphylococcus aureus.Cysts are painless, non-infectious growths filled with keratin or other ...

A painful bump on or around the ear may be a boil, which occurs when a bacterial skin infection develops in a hair follicle or oil gland. Over time, pus collects in the lump. Boil sometimes go away, ...