If you truly said nothing to anybody else, then you have nothing to fear. Ignore them as they are drama queens who need an audience for their theatrics.
If you did say something to somebody, even off-handedly, it may have gotten to them, but in a twisted sort of way, like playing the kid's game "telephone" (you know, the first kid whispers a phrase into the next kid's ear, and on down the line until it becomes completely twisted around into something else). Since any further participation from you would only muddy the situtation, not clear it up, I would do as another poster suggested and try to contact their landlord about their bizarre behavior.
Truthfully, they sound childish and somewhat mentally ill. They don't have a problem with your condition, they have a problem with theirs, otherwise why care what's said?
I can be a bit obstinant, so I would be taking their picture when they take threatening poses. Tell 'em you're starting a facebook page for flaming drama queens, and you need pictures for the "don't be like this" category. Well, don't say that, unless you want a catfight. Just take the picture and don't make a sound. Then show it to their landlord as proof of harrassment.