It may help with the itching but is probably not a good treatment for poison ivy without talking to your doctor.
Here is what I found:
Econazole comes as a cream to apply to the skin. Econazole is usually used once or twice a day, in the morning and evening, for 2 weeks. Some infections require up to 6 weeks of treatment. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Use econazole exactly as directed. Do not use more or less of it or use it more often than prescribed by your doctor.
Thoroughly clean the infected area, allow it to dry, and then gently rub the medication in until most of it disappears. Use just enough medication to cover the affected area. You should wash your hands after applying the medication.
Continue to use econazole even if you feel well. Do not stop using econazole without talking to your doctor.