Recurrence

Recurrence is a Mesh, but you'll get more results if you search for keywords as well.

"Recurrence"[Mesh] OR recurren*[tiab] OR intractabl*[tiab] OR refractor*[tiab] OR persisten*[tiab] OR relaps*[tiab] OR incessan*[tiab] OR reinfection*[tiab]

EMBASE has exp recurrent disease/

These can also be useful:
recurren*[title] OR repetiti*[title] OR frequen*[title] OR cumulati*[title] OR repeat*[title] OR second*[title] OR multiple*[title] OR accumulat*[title] OR additive[title] OR additional[title] OR subsequent[title]