"Outsmarting Poison Ivy and Other Poisonous Plants" is a great handout from the FDA that provides a concise and thorough guide on how to identify poisonous plants, how to avoid adverse reactions, and how to treat those reactions when they occur.
prednisone psychosis: The incidence of steroid psychoses in patients with lymphoma, multiple sclerosis, severe intractable asthma, ulcerative colitis, regional enteritis, idiopathic thrombocytopenic purpura, rheumatoid arthritis, and severe poison ivy or oak is estimated at between 3 and 6%. The patients most at risk for developing steroid psychosis are those with systemic lupus erythematosus (39%) and pemphigus (21%).
Poison Sumac - several rows of paired leaflets and has one additional leaflet at the end, usually 7 to 13 leaves on a stalk. spots on the leaves look like blotches of black enamel paint and contain urushiol oil.