"Flare-ups" refer to sudden and intense episodes or occurrences of something, often used to describe a sudden worsening or increase in symptoms of a medical condition or a situation.
Sentences with «flair ups»
But some other products I've tried have caused some acne flair ups which I'm super sad about because they made my skin feel so great and soft! (perpetuallydaydreaming.com)
Rather it could be seen among the young emerging talents who inevitably flair up now and again. (artspace.com)