Are you certain something is on the leaf?
Looks more like the leaf is bleached.

Not at likely that it's scale or fungus. Looks like severe lacebug damage. Check the underside of the leaf. Lacebugs leave a shiny residue speckled with dark brown dots of excrement.

Yep it was lacebug damage, I took it too my local garden nursery and they told me to use confidor.
Thanks!

Giving them a little more shade can reduce the damage sometimes. You may also want to apply a insecticidal soap or horticultural soap; also a systemic insecticide; do that every year about a month before you noticed when the problem started (make a note in a wall calendar so you do that next year).

Here is a link that might be useful: Azalea Lace Bugs