Tropicals & Tender Perennials: Blister-like bumps on cv. Joy, 1 by JuliaSF

JuliaSF wrote:
My cv. Joy has had these blister-like bumps on it since I received it in May 2005. They seem to be less apparent on the newer leaves, and haven't spread to surrounding hoyas, but they won't go away.

Interestingly, they look somewhat simlar to the blight on the photo of the h. fuscomarginata on page 114 in "The World of Hoyas" book. The leaves of the cv. Joy are similar to that plant as well.

I really love the huge leaves on this hoya and don't want to toss it. Has anyone else experienced this blight or have suggestions for getting rid of it?

Many thanks, Julia

Here are a couple of photos, though not the most focused.