We were out in the woods exactly a week ago and she
started getting these bumps on her leg. The entirety of the
rash was originally smaller and closer to her skin tone. Now
it's around 3/4's an inch and she doesn't want to go to a doctor,
It is possible that it is poison oak, but it's more likely something else just based off my experience with lots of poison oak in the years I was on search and rescue for our county. Was she ever exposed to poison oak before? Because the reaction to poison oak is a type IV hypersensitivity (it just means that she needs to have prior exposure for her body to make cells that will mount a response during the second exposure). If this is her first time ever even possibly touching the urushiol oils of poison oak, then her body is naive and would not be able to mount a response. It is still definitely possible that it is some form of contact dermatitis. If it has not diminished by a week from now I would say it wouldn't hurt to get it checked out!
Is this the only maculopapular rash on her body or is this just one of the many? Is it itchy or painful? Any fevers or problems breathing? It's difficult to tell but it may just be a hypersensitivity reaction. Any contact with any plant life or animals/insects? I suggest encircling the area with a sharpie to see if it is still enlarging. If this is the only patch on her whole body, no systemic problems, and it's just a bit itchy then I would just apply some topical hydrocortisone to help with the inflammation. For the itchiness take some histamine blocker like loratadine/Claritin or diphenhydramine/Benadryl. If it does expand more, or more of them pop up, then I would go to urgent care. If she starts having some difficulties breathing or the rash has spread and covering entire parts of her body regardless if she is having problems breathing, I would take her to the ED.
Thank you for your reply. It is the only rash, and there's not much inching or pain and there has been no fever or any other symptoms suggesting any reaction, but my health knowledge only goes so far, so that's why I came on here. She got the rash in the woods, I assumed she brushed into poison oak or something because she did fall. But the lack of itching or anything is what brought me here