Is it on the leaves as well as the brachs?? Only thing I can think of is powdery mildew⦠keep and eye out and if it gets worse or starts to look fuzzy white time to toss it ⦠it will affect others if you have more .
I think Poinsettias can actually get variegated leaves. It doesnβt look like pests because itβs in the leaf. Iβd do some good olβ planty research.