The following two possibilities are more likely to be considered in little girls with redness and pain in the vulva or around the urethra. The first is trauma. The so-called trauma is not necessarily caused by violent trauma, it may be, for example, underwear friction, long time running, walking local sweating, resulting in mucous membrane damage. Because the skin of the perineum is relatively delicate in children, a mild injury to the mucous membrane can cause localized pain. There is also a kind of infection. Because the girl’s urethra is shorter and thicker, the bacteria around the perineum can easily cause retrograde infection. Some children drink less water, or the body’s resistance is relatively poor, bathing tub baths, these are easy to lead to the occurrence of urinary tract infections.