Powder Mildew, does it cause random brown necrosis on bottom leaves

I have a powder mildew infection, however Ive noticed that the lower leaves are showing brown necrosis on leaf margins(ie one half of one leaf blade is dead and the rest of the leaf appears unaffected) anyway every time I research PM i just get more images of the reproductive spores on the tops of leaves, does PM kill off the lower leaves in a bizarre way that looks like a virus or something?