I had Erbitux in 2012, along with Taxotere, which wasn't fun, but was doable, although my skin rash wasn't that bad, some of the other side effects were. Other than reducing the dosage or stopping treatment, a few things were suggested or prescribed pretty much what you're already doing, but instead had Minocycline for the rash, and decadron infusions for the Taxotere, so maybe it helped with the Erbitux. I was also given benadryl infusions with each weekly dose of Erbitux, Tylenol to help with fever. Seems those areas more exposed to the sun are effected worse by the rash, so using sunscreen at least 30 UPF, wearing loose fitting, long sleeve pants, shirt. Avoiding hot showers, walking barefoot, moisturizing at night with creams being better than lotions, which may have more relief if refrigerated, putting creams on hands/feet and wearing gloves and socks over that. For nail cracks and finger fissures, regular band aids on finger tips, Liquid band aid, crazy glue, gloves. Washed with mild liquid bath soap like dove for sensitive skin, Aveeno, head and shoulders shampoo for dry scalp, although an oatmeal bath I heard helps. A topical antihistamine to help prevent itching, hydrocortisone, and moisturizing cream like aquaphor, Cetaphil, Eucerin, Aveeno, pain meds, extra hydration infusions, mucocitis care by spraying mouth out with saline at radiation center. I was hospitalized for dehydration, and needed a blood transfusion due to low hemoglobin, and later had conjunctivitis, probably from dry eyes from blocked tear gland, and slept most of the time when I stayed at Hope Lodge alone, which wasn't optimal.

Pretty much side effects cease when treatment ends, but some may take several weeks to resolve like the postures, itching, at least for me.

I hope this helps.