Lemon is used in many liver detox protocols so you could have experienced a mild detox reaction. The skin is one of the places toxins are excreted which can cause rashes/eruptions. You may want to just cut back to the juice diluted in a glass of water and see how you do. Then add in the peel. It's good that they are your lemons from the back yard and don't have pesticides in them. If you are going to eat the peels of any citrus fruit, then you must go organic since the peels hold on the pesticides.