Poison Ivy

Source: American Academy of Dermatology

Many people get a rash from poison ivy, poison oak, and poison sumac. This rash is caused by an oil found in the plants. This oil is called urushiol (you-ROO-shee-all). You find this oil in all parts of the plants — the leaves, stems, and even the roots. The oil can stick to almost anything. If you touch a pet's fur, gardening tool, or sports equipment that has the oil on it, you can get a rash. Dogs and other animals do not get this rash. Only people get this rash. The oil can even be spread by airborne particles when poison ivy is burnt in a bonfire.

The itchy, blistering rash may start in as little as 4 hours or as long as 2-3 weeks after you come into contact with the oil. The rash is not contagious and does not spread. It might seem to spread, but this is a delayed reaction. Even if a person touches the rash or the fluids in the blisters, the person cannot get the rash. The person has to touch the oil to get the rash.

Zanfel and Tecnu are two products that can inactive urushiol if applied within a short time of an exposure. They are ineffective if the rash has already developed. Be sure to wash all clothes and equipment with hot water and ordinary laundry detergent.

If you do develop a rash and itching there are several over the counter remedies which may provide some relief. An oatmeal bath (Aveeno Oatmeal powder) or a cool compress with Domeboro solution may help dry up weeping blisters. Since the itch from poison ivy is not caused by histamine release, newer antihistamines such as Claritin, Allegra, or Zyrtec are of little use. Older antihistamines such as Benadryl have some potential for relief, largely through side effects of sedation, which at least allow for sleeping despite the itch. Calamine lotion is inexpensive and can help with itching.

Most people see the rash go away in a few weeks. Treatment usually requires treatment with oral steroid medication, such as prednisone, for a 10-14 day period. Some people ask if they can get a shot and they are available at all IHA locations. However, the medical literature does not find people who get shots getting better any quicker than those who just take pills. The studies do show that a shot alone is not adequate treatment.