25 Year Old Suffering From Frequent Attacks Of Shingles. Reason?

I am a 25 yr old female experiencing shingles for the 4th time in under 2 years. When I first had it, it was on my trunk and ribs and was fairly severe. The second time, I thought I had an allergic rash because it was on my elbow and forearm area, but the doctor diagnosed it as another shingles out break. The third time was in the same area of my arm and was the exact same symptoms so I did not go to the doctor as I do not have insurance, I just took the antivirals I already had. I just notices a spot on my arm yesterday that has been burning and itching, and this morning I see that the blisters have started to form again. This will be the 4th time in 20 months with the three occurrences on my arm all happening in under 12 months. I am concerned because of my young age, and because of the frequency or occurrence.