Some personal products contain irritating chemicals that can cause damage to delicate skin, and allow a yeast infection to take hold.
Some women have found that scented or colored toilet papers can damage the delicate membranes in the genital area or cause irritation, which then gives yeast a chance to invade. The same is true of scented laundry detergents and fabric softeners. Feminine deodorant sprays that contain scents or chemicals that cause irritation should also be avoided. Some personal products may also change the pH level in the genital level, triggering a yeast infection.
Be sure to use an unscented soap in the shower or bath, and do not use a soap that contains a disinfectant, because it kills the bacteria that keep yeast in check. Neutrogena™ is a good choice. Since antibiotics are so commonly added to many personal products, be sure to check the label to make sure. Some condom brands, steroids, for instance, contain anti-bacterial agents, and can trigger a yeast infection in both men and their partners.
If you have recurring yeast infections, you may even need to switch to a dish soap that has no antibacterial agent, and avoid household cleansers that promise to kill germs.
Since each person is different, a personal product that works well for one person could trigger a yeast infection in someone else.