Hi my names Ashley,
I have the same problem but in a (girl way) yes they can size up to 3cm but that's about it. You can try home remedies & cortisone-10 helps it go down tremendously & you'll be able to use it for 7 days. That's what my doctor told me anyways it's normal for men & women to get them & is not considered a disease (even though it may look like it). & try to avoid as much soap as possible that can also irritate it on the skin & try to keep the area as dry as possible, especially if you take a shower & get out to dry (just dab where it's located at) it can go away on its own as long as you treat it like its suppose to I would also go to a doctor & ask him or her what you can do about this.
(Hope this helped a little)