Does anyone know what this could be? She has another one on her ankle and one up along her diaper…

Does anyone know what this could be? She has another one on her ankle and one up along her diaper line. They seem to be painful and at first we thought the one on her arm (photo) was a mosquito bite but it hasn't gone away. The one on her ankle we dug and and picked at because we thought she may have had cactus in it. ( we would take her turkey hunting and plus there is cactus pieces all over our house.) but the one on her diaper line just showed up this morning. (It's red around the one in the photo because I was inspecting it closer)