After years of smoking can you become allergic to nicotine?

You could be allergic to the cigarettes. Try to take some antihistamine or antiallergic medications for the rash and apply calamine lotion locally.

Avoid smoking, join a smoking cessation clinic to help you quit. Talk to your doctor about it.

If the rash still does not resolve, talk to your doctor about a course of steroids and see if that helps.