Betty
Hi, I just went through the same thing...none of the cortisone creams or anti-itch creams helped. Reading some home health remedies on the web (go to key word: poison ivy/sumac poisoning), I got some good tips there. One that worked for me was Tea Tree Oil...stopped the itching and reduced the redness; however, I did get an antibiotic shot and a cortisone shot because my arm was swollen three times its size and doctor was concerned it could be from a snake or spider bite rather than sumac or poison ivy. Bathing the area in an epsom salt bath also helped.