"Huge clinical trials show that putting honey or sugar on antibiotic-resistant infections of the skin will often kill the bacteria," Root-Bernstein said. "This is one of the oldest treatments that exists. The reason it works is the same reason that sugar protects jelly from going bad. Basically, sugar is a preservative is the simple explanation. The more technical explanation is 'osmotic pressure.' Bacteria and fungi can't grow on something that has a high sugar content because the sugar sucks all the water out of the cell."
And the cellophane your candy is wrapped in? Early dialysis used similar cellophane tubes. "Every time someone unwraps a piece of candy, they're probably unwrapping a piece of medical history," Root-Bernstein said.
Check out some tips on Halloween safety at the FDA .
SOURCES: Robert Root-Bernstein, Ph.D. professor, physiology, Michigan State University, East Lansing, and co-author Honey, Mud, Maggots and Other Medical Marvels; Hector Valdivia, M.D., Ph.D., professor, physiology, University of Wisconsin Medical School, Madison; FDA brief summary; University of Wisconsin press releases