I wouldn't be surprised if eventually we'll figure that what we call "Alzheimer's" is in fact a whole bunch of different diseases that all cause plaque buildup in the brain.
Same with atopic dermatitis. Everytime I talk to someone and they notice the red patches on my skin and I say it's atopic dermatitis, they immediately start rambling about how the friend of their cousin's barber totally got that fixed up with that magical treatment and I have to try it. At which point I tell them that atopic dermatitis is mostly a symptom, not a single disease.
