Could this be an allergy?

Hi everyone. I have been having some symptoms that might be the result of an allergic reaction/contact dermatitis and I was wondering if anyone experienced something similar. I wore a pewter necklace last Saturday. On Monday I started to have an itching sensation, similar to needle pricks across my neck, starting at the spot where the necklace pendant was touching my skin. I also have a few little, not so noticeable bumps there. I don't have a rash, and the itching isn't severe, but I still have it five days later (you wouldn't notice anything was wrong with me by looking at me, except when I itch and make my skin red). I tried hydrocortisone cream, but it made my neck burn/exacerbated the needle-prick sensation and I had to wash it off. I am thinking the pewter pendant may be alloyed with nickel, although I haven't had any issues with my other jewelry, some of which is probably alloyed with nickel (I have a lot of cheap jewelry I buy from various places and I have no idea what the metal is).

I tried doing some research but it isn't clear if this could be an allergic reaction since it started 2 days after contact (which I read is possible but less common), and I don't have a rash. But I don't know what else could be causing this, and the bumps and itching started at the exact spot the pendant was resting on my neck. Any thoughts on whether this might be an allergic reaction, and what might help ease the itching?

Years ago I had a case of prickly heat, also known as "Heat Rash". The symptoms feel like hundreds of little needles being jabbed into one's skin.