Well i cant say without seeing but, the worry would be skin cancer which is slow growing and can be regularly checked for changes, like telltale signs. Its the abcds of Cancer. Asymmetry- so ur looking for a sudden shift of one sides edge
Boarders- any parts or outside are spreading past and imaginary line. Think if a cookie cutter and its spilling out
Color- so its getting darker or spotty
And diameter- its growing
I think the dr isnt worried because otherwise, if its not a bother, then its probably nothing. Anything environmental like allergies or a fungus (like dandruff or ring worm... candida) would bother u and so would eczema and dermatitis. Basically their is a change or aliment that comes from anything thats a thing. Other then that, everyone should do the abcds as a regular awareness with all skin tag, growths or beauty marks, as my family calls them. That's a cute name for moles!!! If everything is staying put then i wouldn't even worry. It could be a lil subeasous thing too ..if u mess with it and it opens, then sweat gets in...and dirt. Now u made a problem. S9 don't make no problems!!!! If anything get an otc anti fungus cream. Its embarrassing but yeast infection isle has the best options in one place. 7 day cream because the more, the better and not the weird pill things.. doesn't have to be name brand either. Just so u can kinda see every options they market for these sort of things. I Do it for my sons diaper rashes if dr is closed