When the skin meets poison ivy , the result is often an itchy, blistering rash that can take days to fully manifest. But how long does poison ivy rash last ? Most answers float around “a few weeks,” but there’s more beneath the surface. Rather than simply listing durations, let’s explore the biological timeline , treatment impact , and individual differences that influence this uncomfortable condition’s lifespan. ⏰ Understanding the Timeline: What Triggers the Duration of a Poison Ivy Rash? The moment your skin touches urushiol , the oily resin found in poison ivy , your immune system may go into overdrive. According to the American Academy of Dermatology (AAD) , symptoms generally begin within 12 to 48 hours after exposure, but the rash can last between 1 to 3 weeks , depending on severity and immune response. While the itchy blisters and red streaks may peak during the first week, many cases linger well into the third—especially if scratched or left untreated. Individuals wit...