Chicken pox is a common infection caused by the varicella virus. It is typically a disease of children, however occasionally it is contracted by adults who are not immune, most likely because they were not vaccinated. Generally speaking, the number of cases of chicken pox are very few, because most children are now vaccinated against the condition.
Being infected once with chicken pox gives you immunity to the condition, so it is unlikely to get it twice. However, the chicken pox virus never totally leaves the body after an infection. Rather, it remains dormant inside certain nerves in the body. In times of stress or illness
, it may reactivate, causing a local skin reaction consisting of pain and blistering spots. This skin reaction is known as shingles, at it can occur in anyone who has previously had chicken pox.
I would suggest that you go to see your primary care doctor
right away to see what might be going on. In addition to an attack of shingles, there are multiple other conditions that could cause a rash on your back, and your doctor will be able to decide if you need a specific treatment. In the meantime, keep the rash covered and do not scratch it, as if it is shingles, it is potentially contagious.