If you are allergic to novacaine, does novacaine cross react to lidocaine?

Yes - it does. I am living proof - I was having not so good minor reactions to lidocaine possibly due to the multiple dental treatments I have had. But at 40 having my 1st epidural of 10mg of lidocaine, it set me into plethora of severe reactions, PVC's, heart palps, shaking & tremors days after the injection, weakness, tightness of the chest anxiety & extreme sick feeling. Diagnosis was not placed on an allergy to it at that time, they said post partum anxiety( I cried BS) .. it wasn't until 4 yrs later, I received a hip injection of Procaine ( Novocain) & 24 hours later I broke out in hives, felt as if my face was burning off my body & then all these other symptoms came back 2 fold in the coming days... ER prescribed 6 day ok steroids of course... yet the tremors, weakness & anxiety all still hit & they are still occurring hit & miss. this is now 3 weeks later. Physically & Neurologically it has been hell on me!

No such reactions were found, however it would be best to check it with your healthcare provider as meds have different effects on different individuals, please also read: https://www.drugs.com/interactions-check.php?drug_list=1464-0,1944-0.

Provided Novocain is: Procaine Hydrochloride