Acid in Lime Kills Bacteria
Lime juice contains a high concentration of citric acid. Because of its acidity, citric acid has certain anti-septic properties. The citric acid in lime juice is known to be effective against a variety of bacteria that can lead to infection in wounds.
Acidity Damages Cells
Though the acidity in lime juice may fight bacteria, it will also be very irritating to the wound. Not only will the lime make your cut or scrape sting more, it might also damage or kill some of the healthy cells surrounding the wound. This could mean that a minor wound could take longer to heal.
For minor cuts and abrasions, the best cleaning substance is plain water. Using only water it is possible to remove dirt and anything that could lead to infection from a wound. If you want to gain any health benefits from the lime, you are better off drinking it rather than applying it topically.