Toxic Consumption Illness

Every settlement has a story about the scavenger who found something in the ruins, sniffed it, licked it, and spent the next three days regretting that decision from both ends. The wasteland has a term for this particular brand of stupidity: chewing the mystery.
  Toxic Consumption Illness is a severe internal poisoning disease caused by ingesting necrotic, chemical, or otherwise contaminated substances. The Infection within the body reacts to the foreign material by attempting to metabolize it as nutrients, flooding the system with corrosive enzymes that dissolve tissue and organs from the stomach outward. Blood vessels, nerves, and vision pathways corrode under the chemical assault. The disease is most commonly seen in scavengers, daredevils, and the terminally curious who eat, drink, or taste-test items that were never intended for human consumption, or whatever passes for human in the post-Fall world.
  Transmission is exclusively through ingestion. Spoiled food, necrotic material, mutated flora and fauna, chemical residue, expired culinary goods, unknown scavenged substances, experimental alchemical mixtures; the list of things that can trigger the disease is as long as the list of things that should never go in your mouth. Guides may inflict the disease as a consequence for any character who eats something not designed to be eaten.
  The progression is fast, advancing every four hours in play or upon attempting to consume another toxic substance. Early symptoms include nausea, abdominal pain, and a metallic taste that will not leave. At Stage 1, consuming any Meal or Brew requires a point of Resolve to keep it down. By Stage 2, the body has given up on retention entirely; Meals and Brews pass through the system without providing any benefit or detriment. Mid-stage dehydration, lesions around the mouth, and fevers slow everything down. The severe stage brings blindness as pupils cloud and organs begin to fail. Death at Stage 5 comes from organ failure and complete collapse of the Infection's regenerative cycle.
  The treatments carry the same blunt practicality as the disease itself. Stage 1 has no cure; it has to get worse before it can get better. Stage 2 requires a Basic Medical tending with a strongly recommended lecture about the difference between food and toxic substances. Stage 3 demands forced hydration and easily digested food, administered while angrily explaining why that particular thing does not go in your mouth. The palliative care option at early stages involves Toilet Paper and a dedicated tour of the site's bathroom facilities. The disease is not without a sense of humor about the lessons it teaches.
  Death prior to Stage 5 cures the disease entirely. The body resets through the Mortis with a hard-learned lesson and, for survivors of the early stages, a telltale green discoloration around the eyes and mouth that marks them as someone who learned the hard way.