It looks like pale green spots on the branches and is killing the plant. Can you help?
My Azalea Has a Disease That I Have Not Seen Before
Certified GKH Gardening Expert
This sounds like it might be lichen. Lichen does not kill the plant, but rather often attaches to plants that are dying. What other symptoms are you seeing? This will help better identify what is killing the shrubs.
It would not hurt to treat the plant with neem oil. It will kill both any fungus or pests that may be attacking the plant. Here is more information: