Final answer:
Corticosteroids increase the risk of candidiasis by decreasing the body's immune defense, which allows for an overgrowth of Candida albicans, particularly in the vagina.
Step-by-step explanation:
The use of corticosteroids increases the risk of candidiasis primarily by C. Decreasing host defense, particularly in the vagina. Corticosteroids can suppress the immune system, which may reduce the body's natural defense mechanisms against infections like Candida albicans. This type of yeast is normally kept in check by the body's immune system and the presence of other microbes like lactobacilli. When corticosteroids interfere with these defenses, Candida can overgrow, leading to infections such as genital or vaginal candidiasis, also known as a yeast infection. Typical symptoms include inflammation, itching, and thick white or yellow discharge.