It is necessary to change underwear daily. It is a favorite place for germs and bacteria. If you want to be healthy, then it is an essential task.
If you are a child, men or women everybody should change underwear at least once in a day. When we go to the washroom, our panty becomes a little bit wet.
In the summers because of sweating there is humidity in the underwear and bacteria grow in the humid environment.
So bacteria ports panties. To save yourself from these bacteria at least everyone should change panty daily. If you do not do so then there may be rash, itching and infection.