Hi Peter.

Thank you for asking your query at DoctorSpring.

My first instincts are
telling me that it could be herpes zoster or shingles. If you have
had the chicken pox before, you could get shingles later on in life.
The varicella zoster virus that infects you with chicken pox can
remain dormant for years, and come back later as a band of rash and
sensitivity somewhere in the body. It can be itchy and sometimes
even painful. Not to worry as this can be easily treated with
anti-viral medication.

Other possibilities for your symptoms
is a simple contact dermatitis or allergic reaction,
in which case there is a skin allergy from something in direct
contact with your skin. Here's what I suggest:

Observe the rash. If it is persisting for more than 2-3 days or if there is any pain get in touch with your Doctor. Your Doctor may run some tests including blood tests
and maybe even a biopsy of your rash to test for antibodies. The
most likely conditions are easily manageable so if you follow the
treatment as your doctor suggests it should clear up in no time.

Take care and good luck.
Please feel free to ask followup questions.

Thank you