Yeast Infection After Sex: What Causes It, and How Is It Treated? Some people with yeast infections develop a red or scaly rash. The skin irritation can sometimes be confused with herpes sores, which is why these two conditions are often confused So, can sex toys cause UTIs? We asked urinary health experts, and the short answer is maybe! Further research is needed on this topic, but we know that anything STD Risks from Shared Sex Toys: What You Need to Know? How to Know if It's BV or a Yeast Infection? Evvy STIs And Sex Toys: What To Know