I Am 42, Male, No Health Problems, No Medications. Five

I am 42, male, no health problems, no medications. Five days ago I developed a rash, looks like chicken pox on my torso and back, itchy, worse at night. It spread to shoulders and behind knees. I seemed to develop some constapation today and yesterday not sure if this related. No fever, no pain other than itch. I didn't travel outside Boston evenly, I have been vaccinated against chicken pox as a child.