Hi.. Thanks for the query.. Lortab also contains hydrocondone and Apap or Acetaminophen and is commonly given prior and post dental treatment.. Many a times first encounter of the body with the irritant does not produce sufficient antibodies that it cause allergy symptoms by fighting with the allergen particles. But on progressive exposures the antibodies becomes sufficient in concentration and when the allergen enters the body the antibodies fight with the allergen leading to allergic reaction.. This is appearing to be the case.. You should stop taking this painkillers combination and can take Ibuprofen, Sleeve etc for pain relief after consulting emergency room.. Also take benadryl to reduce itching, take cool water bath and apply calamine lotion to soothe the skin.. Hope this helps.. Regards..