Do all boils or sebaceous cysts need to be cut out or drained?

Have it excised. If a sebaceous cyst, it will follow a vicious cycle of filling with sebum, becoming infected, draining, then starting over. If infected now, may require incision and drainage by doctor. Once healed, have sac removed to prevent recurrence. If simple abscess (or "boil"), should not recur once drained.
Not required. . Sebaceous cysts are occluded hair follicles or pores that collect sebum. Although they will not go away on their own, as long as they are not infected, they do not need to be cut out or drained. If they continue to grow in size, or become infected, they will need surgical treatment. The term "boil" implies that the lesion is already infected. If not draining, they require surgical drainage.

Related Questions

I had sebaceous cyst on vaginal lip taking medicine now and was cut open to drain. Now getting boils all over, why?

Need new diagnosis. I recommend getting another diagnosis just to rule out other conditions. Read more...
Allergy? Is that medicine an antibiotic? Could you possibly be allergic to it? Call the doctor who cut open your cyst now and inform them. Read more...