Poison ivy blisters are best treated by washing the body thoroughly to get rid of any trace of the allergen, urushiol. Urushiol is a sappy substance found all throughout the poison ivy plant as well as in poison oak and sumac; as long as it remains in any contact with the skin, rashes and blisters will persist. Once completely clean, there aren't so much ways to speed up the healing process as there are ways to make it more livable. This can be done by taking antihistamines, applying soothing lotions, or taking prescription medication. You should also take care to avoid scratching itches, which may spread the rash, and especially don't pop poison ivy blisters, which can cause infection.
The first step of treating blisters is to quickly wash any skin that touched poison ivy. Poison ivy's allergen, urushiol, spreads easily, and the only way to prevent it from doing so is to wash it off. Washing it off also prevents it from doing further damage to affected areas. Be sure to get under the fingernails as well, where urushiol can become trapped. You should also remove and clean any clothes, apparel, or other objects that may have touched the plant.
Some suggest using rubbing alcohol in the cleaning process, as it can help dry up blisters. Don't, however, use rubbing alcohol on open sores, such as popped blisters. It isn't dangerous to your health, but the pain of alcohol on open wounds is excruciating.
Any poison ivy blisters that have formed will undoubtedly burn and itch, but it's important that you resist the temptation to scratch them. If you've washed up thoroughly, itching the blisters probably won't cause the rash to spread, but it may cause them to pop. A popped blister can easily become infected. Infections can turn your manageable condition into something that may need medical attention.
Applying cool, wet compresses can help soothe the skin. Likewise, you might also find it soothing to take a cold shower or bath. Relief might also be found by taking an ice cube and rubbing it lightly over the poison ivy rash.
Taking antihistamines may also help reduce itching. The drowsy effects of antihistamines may also help you sleep and take your mind off the discomfort. Calamine lotion is another good way to treat the uncomfortable symptoms of poison ivy blisters. Calamine can be found over-the-counter at many retail drug stores.
If poison ivy blisters persist, you may need to see a doctor. Doctors can prescribe stronger substances that will knock out severe cases of poison ivy. In such cases, you may be prescribed corticosteroid pills or shots. Doctors can also prescribe extra-strength lotions and creams.