Summary
January 18, 2018: An article in National Geographic discusses the way illnesses affect how we smell. The article mostly focuses on how some people can smell Parkinson's Disease in others, despite it being a very tricky disease to diagnose medically. Tangential topics include evolution, medical research, and the specifics of how certain illnesses change the way you smell. Scurvy makes your sweat putrid. Arsenic poisoning makes your sweat smell like garlic. Diabetes makes your urine smell fruity.
Humans, of course, are not well known for their sense of smell - dogs on the other hand, are, and there is definitely work underway to train dogs to detect cancer by scent. So far the evidence is mostly anecdotal, but clinical trials are in progress. Presumably if a dog can tell a tumor by scent, it could also be trained to sniff out other problems.
Source
Game and Story Use
- The scent cues listed above and in the article can be used as clues in a game.
- You make your Perception check and notice the king smells of garlic again. He's been looking pale, too. Is he in danger from vampires, or from a poison-wielding assassin?
- Other than sickness, what else might change someone's scent? Could alien mind-control, necromancy, or possession be detected by a keen nose? Might they be accompanied by a scent that's almost strong enough to incapacitate?
- Characters (NPCs or PCs) might have these abilities as a special skill. A piss prophet, or drug-sniffing dog, dialed up to 11.
- It's a good match for a Ranger and Druid types because it's got a little in common with Tracking by scent and a little in common with being a holistic traditional medicine healer.
- This also allows for those characters with discriminatory scent advantages - or their pets - to detect other forms of disease such as zombie plague or things like the "Ripley" pathogen from Stephen King's Dreamcatcher.
- Non-human characters may well have an advantage in this.
- This could also allow some kinds of monster to ignore those with specific infections … possibly because they smell different to humans and thus either "bad to eat" or "like us".