1875, "break out afresh," back-formation from recrudescence or else from Latin recrudescere "become raw again, break open afresh." Related: Recrudesced; recrudescing.
These political movements recrudesce from time to time
Such boils tend to recrudesce
recreation
recreational
recrement
recriminate
recrimination
recrudesce
recrudescence
recruit
recruiter
recruitment
recrystallization