Now I have a swollen, split lip. Could this be a herx?

Yesterday I was experiencing swelling and itchiness on my hands and feet and now today my lip is very swollen and sore.  I took a zyrtec yesterday and the itchiness has not come back since but my lip remains swollen and sore.  I realized last week that my lip was slightly swollen but I just ignored it because this has just been another symptom I've been periodically experiencing the past few years that doctors can't figure out, although this is the worst it's ever been.  I called my doctor's office yesterday but they have not called back yet.  I'm not bugging them because it's not unbearable and I know the doctor is not in. 

Could it be possible that Lyme or one of the co-infections is causing my lip to swell too?  Has anyone else experienced this?

Thanks!

Thanks Dowa, I've been on new meds since February 4th and have not eaten anything new. The swelling of the lip comes and goes but the last few days has gotten really bad. My lip did not respond to the zyrtec I took yesterday morning but tonight it actually feels slightly better. Earlier tonight, I read somewhere that this can be a sign of yeast overgrowth from antibiotics. The PA is back in the office tomorrow so I'll call again then.

Just spoke to the PA and she said it could either be either a reaction to the antibiotics or a herx. At first she told me to stop all meds for 48 hours but since it's not unbearable I asked if I could try stopping just one to see if it helps. I hate the thought of stopping anything that might be successfully killing off the bacteria for any period of time, especially if it's just a herx. Oh well!