First of all, keep in mind that I am unable to diagnose you because I am unable to examine you, this forum is for educational purposes.
The symptoms of parathesia's that come and go are common and do not signify any particular disorder. These symptoms are seen in many disorders such as multiple sclerosis, some migraine headache disrders, peripheral neuropathies, and in anxiety. The good thing is that you have been tested for the 'bad' causes of these symptoms (such as multiple sclerosis) and these tests have been negative. It is possible that your symptoms could be related to the peripheral nerves and a nerve conduction study/EMG might be helpful if that is the case. Given the symptoms that you describe a 'wait and see' approach may be reasonable, since some of the tests (ie LP, SPECT) have more risks than they would provide benefit. One possible medication trial would be neurontin or lyrica for neuropathic pain. This will not treat numbness, but it can take the pain or uncomfortable feeling away.
I hope this has been helpful.
Yes get tested for Lupus and Lyme disease..GOOD LUCK!
Thanks. I already had tests for Lyme (not Lupus). Will ask to have it repeated and get tested for Lupus.