For what it's worth, my RO warned me that if I had spent any major time outside hiking in Southern states, including Georgia, Tennesse, North Carolina and Arkansas and had ever been bitten by a seed tick, then I would have had the same reaction as Markus. According to him, the bite from seed ticks causes your body to generate antibodies that then react violently with Erbitux. These "seed ticks" are very small and only found in the South not the Northeast. You can google Eribitux and seed ticks to see the newspaper stories which all ran in 2008 and then I guess it wasn't news anymore. Apparently they can test you for these IgE antibodies, although my RO never did.
Charm