When do you know you need to see a dr. To get a steroid shot for poison oak?

Depends on extent. The treatment depends on the degree of skin involvement. In general dermatologists recommend oral Prednisone in the dose of 40 - 60 mg slowly decreased in dose over 2-3 weeks or a shot of kenalog (triamcinolone) at 1mg/kg intramuscularly. The problem is that many people flare, even after a several week course of the medicine. Here is the key--wash everything, including your dog if you had your pet with you.
That is up to you.. Poison ivy/oak is not generally considered a dangerous condition, but can be quite bothersome to those affected. If it is not very bothersome to you, otc topicals, oral antihistamine use etc to help with itching..Keep areas clean/dry. If symptoms svere or involving face/eyes, sensitive areas, consult doc..Oral steroids often do the job! rarely injection is required. Best is avoid it... Good luck.
When OTC fails... If over-the-counter treatment (i.e., the orange stuff!) isn't working it's time to see a physician. One significant risk is the development of infection with open wounds. If the rash is widespread, a steroid shot is very helpful. I use them early and often. If a patient has a rash due to poison ivy (or oak, etc.) and has taken the time to come see me, they need aggressive/effective treatment!
Your call. If it itches too bad to sleep and topical cortisol does not relieve it, especially, do not hesitate.

Related Questions

My teenage son has poison oak second time in two weeks can he get another steroid shot?

Try oral medications. Talk to your doctor about using oral medication to treat poison oak (or ivy). For moderate to severe cases of poison oak/ivy oral or injectible steriods can be used. Repeated doses can suppress the body's production of stress hormones. Often an oral tapering dose is used to prevent flare ups and allow the body to restart stress hormone production. Read more...