Porphyria vs. Lupus in folklore

In his article: http://www.straightdope.com/columns/990507.html
Cecil makes a persuasive case that porphyria can’t be an explanation for vampire legends. He also notes that porphyria had been proposed as an explanation for legends about werewolves.

This is interesting. I had always thought lupus was the classic explanation for werewolf legends. Is there anything to this, or am I just getting confused by etymology?

Lupus erythymatosus (translated variously, often as “the red mask of the wolf” - but I think that’s a stretch) is often associated with a characteristic “mask” or reddish cast over the cheekbones, nose, and often forehead, among other things.

This ‘mask’ is not always present, but it makes for a cool name.

While I, too, believe that I’ve seen that explanation for werewolf lore, it would be quite a stretch. Aside from a not-infrequent photosensitivity, LE doesn’t explain much.
I’d assume that you have seen such articles, and that the authors were confused, not you.