My DD had a reaction to peanuts a few weeks ago - coughing and rash mainly. I took her to the GP and she's going to be allergy tested next Feb. I learnt from others on BB that their reactions can get worse, so I would say go to the GP, get her on the (horrendously long) waiting list for testing, and then keep her away from all nuts (advised to me by GP) and you too if you're breastfeeding, until the test is completed.

Good luck!