question: Please can you tell me if mouth ulcers and pimples are a side effect of Giardia.  I was diagnosed with Guiardia about 3 months ago.  I was treated with Flagyl.  6 weeks ago I had a second outbreak, but milder.  I now have white pimples inside my upper lip and ulcers in several places.  My throat is also inflammed and there are a few spots on the back of my throat as well.