Rash & Interferon

My brother has melanoma and has finished 1 month of intravenous interferon. He has also finished 1 month of the interferon shots M, W, and Fri. Just 11 more months to go!
He has developed a rash on his back and chest. It looks like a heat rash. The derm docs took a biopsy and they are "knocking their heads together" to figure out just what it is.
My brother thinks it may be a reaction to the interferon.
Have any of you experienced anything like this with interferon treatments?

Thanks,
Celeste

I developed a rash during the 3rd or 4th month of Interferon treatment.  My dermatologist prescribed a lotion, which helps a bit, but I continue to get new break-outs on my back and stomach.  There are even a few spots on my arms and legs.  It is a side effect of the drug, and is listed on the Interferon package insert.  I've also experienced hair loss, fatigue, metalic taste in my mouth, dizziness, nausea ... pretty much every side effect.  However, I am finished the first 6 months of treatment (halfway there) and I'm counting the months until the treatment is complete.