Not sure as to the side effects you were having, but two main concerns that occur in a very small percentage are severe infusion reactions and cardiac arrest, most which occur the first two infusions, so they monitor you closely, and are to report any unusual conditions.

The first infusion is usually a loading dose, 400mg, a week before radiation treatment begins, and 250mg weekly thereafter, which works as radio sensitizer to make radiation work better, and received IV Benadryl along with the Erbitux to reduce any reactions.

You were probably advised of the notorious rash, which is a good indication the drug is working, but not always. Besides that, there are a few others like "hand and foot syndrome", mucocitis, others that may occur, so prophylactic measures should be taken. The first sign of a rash I was prescribed minocycline.

I was told to use head and shoulders shampoo for dry scalp, and Dove liquid body soap for sensitive skin, and used cetaphil cream for sensitive skin for my neck, and rest of body. Avoid sun exposure as this can worsen the Erbitux skin effects.

Curious as to why Erbitux was chosen over a platinum drug, which is usually preferred, although Erbitux is approved for first line treatment, I'm not seeing it used as often as several years ago.

Good luck.