Poison Ivy Effects. Poison Ivy Relief Spray, Non-Aerosol Side Effects by Likelihood and Severity INFREQUENT side effects Poison ivy is a common wild plant that causes an extremely irritating allergic reaction when you touch it or brush against it. Prednisone for poison ivy is one of the best known medical treatments.
A urushiol is the basic cause of an allergic reaction especially when it comes into contact with the skin. A poison ivy steroid shot works by constricting blood vessels which cools down the affected area and limits the amount of water reaching the rash which disrupts the effects of the allergic reaction. Most people remember poison ivy as a plant that can cause a serious, long-lasting rash, if touched.
Frequently, the rash takes a linear form (as in the top-left corner of the photo) due to the way the plant sweeps across the skin.
Brushing against a poison ivy plant can cause a red, itchy rash with swelling, bumps and blisters.
Hershey Medical Center Summary: Three-quarters of the population will get an itchy red rash if. Triggered by an allergic reaction to the plant oil called urushiol, poison ivy rashes produce a severe prolonged itching that will not stop. The leaves are used to make medicine.