Antihistamines are effective in reducing itch. The two best over the counter brands are Cholor-Trimeton and Benadryl.
There are other drying agents that can ease itching from poison ivy and poison oak, though most are not as effective. Burrow’s solution, witch hazel and zinc oxide work for some people amazingly well. Baking soda is another good remedy if you don’t have anything else in the house and feel that you cannot get to a drugstore.
Counter-irritants like phenol and menthol can confuse the nerve endings into a cooling sensation, but may sting when they are applied and may not give sufficient relief. Phenol and menthol are available in anti-itch creams.
Use a Compress
Soak a washcloth in cool water and place it over the affected area. Then, let a fan blow on it. This cooling/evaporating effect works much the same as calamine lotion, but leaves no residue to soak up any leakage from the blisters.
Colloidal oatmeal will dry up the blisters. This can be purchased at any pharmacy. Aveeno is the most popular colloidal oatmeal preparation and it comes with instructions that are very easy to follow. Apply it with a cloth, or soak in a bath tub with the oatmeal added to the water.
OTC cortisone cream is too weak to treat the rash caused from an allergic reaction to poison ivy or poison oak. However, it can relief itching and give you some much needed relief.
The best herb for the treatment of poison ivy and poison oak is jewelweed, also known as impatiens. This herb works just as well as expensive cortisone creams and is readily available in either your garden or a garden center, or may be bought in powder form from a health food store. If using the plant, slit the stem and put the juice on the rash. It will also stop the rash from continuing further if applied when symptoms first appear. Ball up the entire plant, making sure that part of it is leaking juice and wipe off the sap from poison ivy and poison oak.