Luden's Echo interaction with DoTs intended or bug?

I've recently seen a few times where an enemy has built Luden's Echo and has a Damage over Time effect (namely brand) that if they get enough stacks during the DoT's duration, it will auto proc Luden's Echo. This can be annoying especially if you escaped the other champion, then just suddenly die to a Luden proc.

Not sure if it's intended or not.