Had severe case of contact dermatitis, used triamcinalone cream for two weeks which got rid of it, but it's been about 2 weeks & now it's back. why?

Contact dermatitis: Some cases of contact dermatitis can continue erupting for 3 weeks after initial contact, like poison ivy. Important to identify the substance to which you are allergic so that you don't come in contact with it again. Every time the skin comes in contact with an allergen, the reaction is quicker and stronger. Please see your dermatologist for possible patch testing to figure out the allergy.