I wonder if this could be a shingles activation?

Viruses like Herpes zoster, can reactivate when the immune system is stressed. This can be tested for, a blood test.

It is also possible to get systemic Herpes simplex... and tingling precedes its eruptions too.

I would really demand some testing for both. Antiviral drugs like Valtrex or Famvir or acyclovir can really help if this is the case.