Please bear with me, I'm trying to include what I think may be relevant.
Last Wednesday (9 days ago) my 12 year old daughter woke up with a fever and bad sore throat. She was traveling out of state with my husband, and he took her to urgent care for a strep test. It was negative but they gave her antibiotics (z-pack) anyway because they'd been seeing a lot of secondary infections, and maybe also because she was away from home and had been having sore throats on and off for a month or two, though no fever. Because she was traveling and had other important events when she got home, she kept going. She rested all day Friday, Saturday afternoon and evening, and Sunday afternoon. She seemed mostly better. After camp on Monday, she was very tired. Tuesday she didn't feel well and stayed home, slept most of the day, and by Tuesday evening she was miserable. Wednesday by 9am her fever was about 103 (her normal temperature is under 97, so this is quite high for her). Other symptoms were stuffy nose, sore throat, and some coughing. Doctor said bring her back if the fever wasn't down by Friday. Last night she told me that her vagina started hurting Wednesday night, and she noticed black spots yesterday (Thursday) morning. She showed me, and they're half an inch wide or more. Pediatrician today said she suspects mono, and sent her to a gynecologist for the vaginal sores and for blood tests for possible mono. Gynecologist said it's baffling, most closely resembles herpes, but history doesn't jive, and sent out cultures. I know that some 12 year olds are sexually active, and would not like it but would accept it if my daughter were, but I really don't think she is. She was asked out by a boy a few months ago and decided she's not ready to date yet, doesn't like seeing nudity in movies, but is comfortable with boys and men (unlike what you'd expect if she'd been abused). These are just some of the reasons I believe her that she has not been sexually active. She has been menstruating about 6 months. The possibility of mono made a certain amount of sense since she's complained of a sore throat on and off for a while, but it seems quite a coincidence that the vaginal sores came the same day as the very high fever. In any case, the doctor just called to say the first mono test came back negative (there are some other tests still outstanding).
So, I'm looking for possibilities on what could cause large black vaginal spots/sores in an adolescent female who is post-menses but not sexually active. High fever, stuffiness, and sore throat may or may not be related.