The views expressed by me are for educational purposes only and do not establish a doctor patient relationship.
Thanks for your question.
These symptoms can be related to the shingles.
Shingles is due to the reactivation of the chicken pox virus which can affect the nerves.
The rash is usually blister like and painful along the line of nerve distribution.
The best treatment option is to use an antiviral medication called Valacyclovir 2 grams daily for 7 days.
Gabapentin is another medication that is commonly use along with valacyclovir to control the nerve related symptoms.
Gabapentin is used in the dosage of 900 to 2400 mg daily in 3 divided doses.
The symptoms should subside within 2 weeks in most cases.
Another possibility can be autoimmune disorder like Lupus.
This is too early to comment.
But you can see a rheumatologist for a thorough evaluation.
Since I've had shingles for 3 weeks already, I'm most concerned about getting a new rash. Is this common?
Will blood work discover other causes?
yes this is common -- can occur without proper treatment with medications mentioned above.
yes they will.
blood tests can be ordered to check blood count with differential, sed rate, ANA titer,