The Erbitux rash can be pretty awful. Mine ended up cracking and oozing on my face. My RO gave me oral antibiotics and an antibiotic cream and I moisturizer like crazy. It did calm down eventually and now, at almost 4 weeks post treatment, it is almost gone.

For the mouth sores, I used a product called ulcer ease. I didn't like the lidocaine because it made me too numb and I bit my cheeks and tongue, causing more sores. Te ulcer ease made me just numb enough to quickly down some water or a shake. It wears off really quickly, though.

I hope your brothers symptoms subside soon. In the meantime, staying on top of pain meds so he stays ahead of the pain should help.

Tracy - 33 at diagnosis
SCC right ventral tongue Dx 4/11.
T1N2M0
1st resection 5/11.
Bilateral neck dissection: 2 pos nodes
2nd resection w/graft 6/11.
Erbitux x 11 completed 9/11. IMRT x 30 completed 8/11.
3 month MRI and PET/CT all clear.
6, 9, 12 and 24 month post treatment MRIs all clear.