Azalea lace bug damage
My azaleas got lace bug damage and it affected the entire plant last summer before I realized what was happening. They looked like your picture of that damage. I used an organic insecticidal and fungicidal spray all over the plants twice. Will they come back next spring?
Certified GKH Gardening Expert
Your plants will probably survive, since lace bug infestations don't usually kill azaleas. But the lace bugs may come back. In case they do, here is some more advice on controlling them: