I have been on the 150 mg of Tarceva since Feb. 05. Rash on the face at the beginning and then it pretty much went away. Blisters on the toes and slight rash on my hands and other areas of the body. Splits and cracks in the skin on the fingertips.
Then the rash got real bad on my scalp and turned into that big scab you described. Going down to 100 mg, using an antibiotic pill and cream...I don't know what made the scalp scab go away. Went back up to the 150 dose and the scab is back on the scalp. Not as bad as it was...yet! Sores inside the nose too which have been there on and off for months. I will live with them...there is no other choice, the pill has shrunk the tumors to nothing. I'm happy even if there are side effects.
Hope it is working for your father.