A.F.
Sounds like a reaction to me. My daughter accidentally ate something that came into contact with peanuts (but not actually peanuts or PB) when she was 12 mos and that was her first reaction. Similar occurrence when a PB cup was touched to her lips accidentally at 14 mos (but not ingested). We had her tested and she is off the charts allergic so thank god she never ingested it. The "accidents" happened at a daycare (stupid people when I gave instructions of no nuts/peanuts till age 3) -- she hasn't been there since the 2nd occurrence and we have had au pairs pretty much since then.
Just as FYI- you or your husband or family do not have to be allergic to foods for your kids to get them. A lot of times, kids of allergic people (even hayfever for example) can wind up with food allergies (in fact, if you and your husband both have ANY sort of allergies, those allergies can manifest themselves in any way -- including food -- with an 80% chance your kids would have allergies). Then there is always the odd ones where the parents have no allergies at all and kids end up with them too....so there are no guarantees. My recommendation is to have her back-scratch tested at the allergist (takes all of 30 minutes) for foods -- does the major ones (soy, egg, milk, gluten, fish, shellfish, tree nuts, peanuts). Our daughter turned out to be milk, egg, peanut, fish allergic (explaining her eczema she had from birth). Best wishes and hope it was just teething but better to be safe than sorry! Peanut allergies can progress/escalate from hives to worse reactions over time.