Will poison ivy, oak and sumak run its course without medication?

Possibly: Rhus dermatitis (poison ivy, etc. ) will resolve spontaneously. Benadryl (diphenhydramine) can help with the itching. Lotions such as calamine, or over the counter Hydrocortisone may also benefit. If you have a severe case you may benefit from prednisone. However, make sure your doctor puts you on a prolonged course of at least two weeks as it is common to experience rebound flares with shorter courses.

Yes: However it will go away much quicker if you get benedryl gel over the counter, plus cortisone cream, mix them together and rub them over the affected areas.