The length of time it takes for your rash to heal really depends
on your body's immune system. Some people can clear up in days,
some take up to a month. A few important things to note:
If your rash isn't spreading, then you shouldn't have to keep
washing with Tecnu. If your rash is spreading, that means you
are coming in contact with the plant's urushiol oil again. Usually
recontamination (if you haven't been around the plants again)
happens because you are picking it up off an object that has been
in contact with the plant oil such as gloves, gardening tools,
mountain bike, pet's fur, etc.. Those items may need to be
washed as well.
If the rash isn't spreading but it is getting worse, you may
want to consult a physician. Signs of infection can include
very red skin, puss, swelling, fever and pain.
If the rash isn't getting worse, it may just be that your body
needs a little time to heal.