I Am 52 Yrs Old And Have Experiences A Itchy

I am 52 yrs old and have experiences a itchy rash on the bottom side of my right arm. There appears to be a rash developing and it covers an ares of about 3-4 inches in length, it is slightly raised (no blisters, yet) and is about 1 inch wide. My left arm is now becoming itchy with a similar rash in appearance only not as large. I am not the kind of person who gets skin irrations and rashes. I am leaving tomorrow on a cruise and now I'm concerned that this rash may be an outbreak of shingles. What can I do to combat this and still be able to go on this cruise?