Hi Waybuloony, my ds is also allergic to egg. He has never eaten it, but developed hives on skin contact with raw egg at around three months. No way you can blame weaning for that, and I'm certain that whether you give mushed up or whole pieces of food, it won't make any difference at all to whether your child is allergic or not! There are acutally studies going on at the moment to determine whether the early introduction of small amounts of allergenic foods can help to reduce the occurrence of allergies rather than encourage them - as Siddhartha says, you can tell the gp's that they are more likely to blame than your weaning technique!
I am breastfeeding, and have cut out egg from my diet. You will get mixed views on whether this is necessary or not, but I found that my ds had a couple of small patches of eczema which did clear up when i stopped eating egg, so it might have been making a difference, I don't know for certain. Besides, I know that if I avoid egg, there is no chance that ds will come into contact with it by accident.
When you saw the consultant, did they spt for just egg, or for other foods too? If only egg, the bloods may be to determine whether there are other allergies present. If they skin pricked for more than egg, the RAST tests will merely back up what you already know. Neither test can tell you the severity of an allergy, but they do give an indication of how likely it is that you are allergic, iyswim? So a larger weal/higher rast score just means that you are more likely to be allergic. The only true test of an allergy is an actual reaction, so if your dc has hives and vomiting on eating egg, then really you already know without tests that this is what it is...
The good news is that egg is one of the allergies most likely to be outgrown. While it's really common in babies and children, it is far less so in adults. It is likely that your dc will be able to tolerate baked egg before less well cooked egg if he starts to outgrow, as the cooking process changes the protein in the egg (which is what causes the allergy) and makes it less allergenic. This is why they test for both raw and cooked.
You will find these boards really useful for help and advice, so do keep posting - there are lots of mums on here who are far more knowledgable than me who have helped me a lot. Good luck! 