To be honest, I think some people mean it as a compliment. This comic, of course, refers to skepticism. Don't expect HKPP patients to take it kindly. It's nice to be cautious about saying things that can be taken out of context. It may help to realize that people who are chronically ill have been through a lot and that we may feel like you're being rude even if it's not your intention.
I wouldn't feel the need to say this if it wasn't a real issue.
"You don't look sick."
"Never heard of it. Is it REAL?"
"Well what are you doing to fix it?"
"You're going to have to try harder."
"You need to try. You need to really try."
"It sounds like you're making excuses."
"Just trying to help. I wouldn't just GIVE UP."
And the ever-popular "think positive" and "pray more".
A good rule of thumb is that if you're not sure whether or not you should say something, it's probably best not to say it. But let's face it - many of these folks are too stuck on themselves to believe they could be wrong, and those kind of people love going around trying to fix or degrade others. Patients, don't be afraid to stand up for yourself. Sometimes, that's the only way to be respected.