My dad is suddenly having rashes all over his body and he took alpha chemo trypsin for 4 days what could it be?

Stop the drug : First of- is stop the Alpha chemo trypsin or whatever new medication that he takes. Second, call his primary care doctor and go to see your doctor for further evaluation and treatment. Drug induced rash is very common and sometimes, not only annoying and that could be lethal in a few condition- like in steven johnson syndome etc.