Answer: flaredup

AnswerCrossword Clue
FLAREDUPErupted
FLAREDUPSuddenly became angry.
FLAREDUPBecame suddenly angry.
FLAREDUPBecame excited.
FLAREDUPBecame suddenly excited.
FLAREDUPRecurred, as an ailment
FLAREDUPCame back strong, as allergies