White PLA prints frequently have rough sidewalls near top of the print
If you want to change settings on some area of your part check out modifier meshes in Slic3r.

It looks like to0 much heat is delivered when solid infill starts and some melting occurs. See 3D Printing Problems #22: Extrusion Temperature Too High. 

You can try:


Lower extrusion temperature
Lower filament flow
Improve part cooling
Lower print speed