Poison ivy normally resolves on its own within one to three weeks, according to MedicineNet. A doctor may prescribe an oral corticosteroid to treat a rash and blisters that cover a large area of the body, and he may prescribe antibiotics if infection develops, states Mayo Clinic.
Using soap and water to thoroughly wash the area exposed to poison ivy within 10 minutes of exposure may prevent the rash from developing, reports WebMD. It is important to scrub under the nails to avoid spreading the poison ivy oils to other parts of the body via the fingers.
Once the poison ivy rash appears, applying cool, wet compresses to the affected area for 15 to 30 minutes a few times a day helps alleviate the itching while waiting for the rash to dissipate, advises Mayo Clinic. Immersing the body in a cool oatmeal bath also provides relief from itching. Calamine lotion and over-the-counter corticosteroid creams applied to the rash control itching as well. Oral antihistamines ease the itch too and may help promote sleep. For pain relief, over-the-counter oral medications are effective, adds MedicineNet.
If a severe allergic reaction occurs that involves facial swelling, difficulty breathing or problems with swallowing, emergency medical attention is required, warns MedicineNet. If the face or genitals are affected by the rash, medical care is also necessary.