Shingles at 19 years old, is this possible?

It happens: I've seen it in toddlers as early as 15 months and it is seen throughout life. Though more common in older adults, it is not rare.

Shingles: Shingles can certainly be found in humans of any age. But, the reality is that if they have never had chicken pox then shingles is impossible. All children in america are vaccinated against chicken pox these days, so they do not have the experience that their parents and grandparents had getting chicken pox and then being at risk for shingles. I would first question the diagnosis for this reason.