The itch is driving you crazy! You need help now!
Rashes caused by poison ivy, poison oak, and poison sumac all look the same: raised, red, blistering bumps on exposed areas. They are all caused by hypersensitivity to urushiol-containing plants. The rash and itching begin 24 to 48 hours after exposure and worsen over the next few days. Assuming you showered before the rash appears, poison ivy is not contagious. The only way to share it is if the plant oil is still on your skin and you touch someone else. The fluid from the blister is not contagious.
Although in some cases people worry about their appearance, for most it is the itching that prompts them to seek medical attention.
Here are 5 tips for quick relief.
1. Use an over-the-counter antihistamine. Over-the-counter antihistamines are just as good as prescription antihistamines. The main benefit of using these is decreased itching, although they may decrease swelling a bit. The main side effect is drowsiness with certain antihistamines, although this may be of benefit if itching keeps you awake. Non-sedating antihistamines are Claritin (loratadine) and Zyrtec (cetirizine). Sedating antihistamines are Benadryl (diphenhydramine), chlorpheniramine, and doxylamine (found in sleeping pills and Nyquil). If these are effective in lessening your symptoms and the appearance of the rash is not a concern, an antihistamine may be all you need. The rash will go away on its own if you can wait, which usually takes 2-4 weeks.
2. Use an OTC topical preparation. Calamine lotion and oatmeal baths help relieve itching, but they don’t actually lessen the rash. Hydrocortisone 1% cream is effective in reducing itching and healing the rash in mild cases. For a more serious reaction, prescription medications may be needed. Hydrocortisone decreases the body’s reaction to the damaging oil, making the rash appear less red and irritated. Any of these can be used in addition to an antihistamine.
3. Call your doctor to get a prescription. Your doctor may be willing to prescribe medication over the phone or may ask you to come in for an appointment to make sure your self-diagnosis is correct. Prescription options include stronger steroid creams, steroid injections, and steroid pills. For small areas of rash, creams are most appropriate. However, for larger areas or rashes on the face (especially if the eyes are swollen shut) steroid injections or oral medications are appropriate. The rash usually starts to get better 24 to 48 hours after starting treatment. Don’t make the mistake of stopping the medication as soon as the rash seems to improve; it’s likely to come back if you leave too soon. A five-day treatment plan is the minimum, but 10 to 14 days of medication is often recommended.
4. Watch for secondary infections. Any open area of skin can become infected. If the area of redness is increasing, or especially if you see pus (not just clear fluid from the blister), see your doctor to see if you need an antibiotic.
5. Do not use triple antibiotic ointment or Benadryl cream. When applied to the skin, both the neomycin in triple antibiotic ointment and the active ingredient in Benadryl cream (diphenhydramine) can cause a rash that resembles poison ivy. Many patients have worsened the problem or confused the diagnosis by using these over-the-counter preparations. (Diphenhydramine (Benadryl) by mouth does not cause this problem.)
Lastly, an ounce of prevention is worth a pound of cure. Avoid contact with the leaves, stems, and roots of plants, which contain urushiol. If you remove the plants, wear disposable gloves and dispose of the plants and gloves. Burning the plant can put the chemical into the air and cause a serious rash in anyone exposed to the smoke.
Copyright 2010 Cynthia J. Koelker, MD