Scared, not sure if I should be or not

(History - 55 yrs old,  DCIS 2003, lumpectomy only, no rads, no tamox, alternate MRI's w/mammos every 6 months, so far so good)

It started yesterday with a slight itchy rash on my arms for which I wasn't real worried.  Last night in the shower I realized my right breast itched.  Afterwards I look in the mirror and see there is a rash on both breasts.  I get real nervous. This AM the arms seemed to be better and the breasts were worse, both of them are quite red (the entire breast) and a little itchy. Co-incidentally I had an appt with my  PCP this AM for my yearly physical so naturally I asked him about it and asked if he thought it was IBC.  He clearly said no as the breast is not connected to the arm.  I felt relieved, for about 5 minutes that is.  The two rashes may be totally unrelated as I was raking Monday night and sometimes that will give me a litttle-bity rash (the leaves rubbing on my arms as I put them in the bag.  But I thought I was wearing long sleeves, maybe not.  And this afternoon the arm rash seems to be just about all gone.

So I have no idea what this is and if the two rashes are part of the same problem.  I would like to think they are because that would mean less chance it is IBC.  Doctor's explanation is allergy, there's a lot of "stuff" out there this time of the year, he says.  There may be but it never bothered me before and it's not like I'm baring my breasts to the world or rolling around naked in the grass.  What kind of allergy affects breasts only?  Sounds unlikely to me.

What do I do?  Do I go to the dermatologist or do I go to the oncologist (mine just retired so I'd have to see the nurse practioner)?  Or do I wait a week or two and see if it goes away?  Would IBC affect both breasts at once?  I know IBC is rare and I imagine it would be rarer in both breasts at once but it's not impossible.  Could an allergy affect just the breasts?  I haven't changed detergents or soaps, no new meds and I'm really not the type to have allergies.