Add soap and infections.
Wounds, especially deep ones would have to be cleaned with soap and water in order not to get infected.
Soap would be made from lye and lard. Lard would come from pigs.
Lye would be made from ash that would be made from wood somehow. This ash would then be processed to lye.
Lye and lard would be combined to soap.
Soap could also be used as a curio.