Generally yes and no. The reaction to urushiol oil (the compound in poison ivy) is an allergic reaction and as such varies from person to person and from time to time. The average though is about 10 to 14 days to recover though for some it will take longer and for others it will be shorter. I now average about 7 to 8 days for an outbreak and I do not treat the rash with anything. I'm of the "mind over matter" camp - I do not recommend this method but it works for me.
Since I am not a doctor - I will leave you with references from noted authorities including the American Academy of Dermatology (AAD) who state similar to what I've written here and in other responses.
