As my mind whirred, Penny screwed her mouth into a wry smile and raised her eyebrows. “What do you make of this?” she asked, sticking out her tongue. Reddish lesions, like bumps on a pickle, dotted the tongue’s front two-thirds on the same side as her blistered cheek. Along with the pocks in her ear, the lesions were the giveaway. To reach those two disparate sites, varicella-zoster virus must have traveled specific branches of the facial nerve. Penny had shingles, all right—but in a far-from-ordinary location.

“Ramsay Hunt syndrome,” I breathed, “straight from the textbook. I haven’t seen it in years.”

. . . Or Something Much Rarer?

In 1907, James Ramsay Hunt, a neurologist at Cornell Medical College, published a seminal paper in The Journal of Nervous and Mental Disease. In it he noted that virus-induced inflammation of a knot of nerves (“the geniculate ganglion”) near the auditory canal yields a facial eruption in the exact pattern revealed by Penny’s exam.

Today, the National Organization for Rare Disorders estimates some 15,000 people experience Ramsay Hunt syndrome in the United States each year. For contrast, an estimated 1 million Americans come down with shingles each year.

Penny remained perplexed. “Why did I get it now? And why here, of all places?” she asked, pointing to her ear. “I was immunized last year.”

“Some patients still break out in a modified rash,” I mused. “But this is not a place I would expect a vaccinee to develop lesions.”

I paused and thought harder. “Did something else stir up the dormant virus near your facial nerve, I wonder?”

That’s when an “aha!” look lit Penny’s eyes. “How about major dental work?” she offered. “Earlier this spring, I had several implants done.”

Of course—it was a perfect, recent trigger. The deep bite of the dental drill and fixing of the titanium “roots” of the implanted teeth would have rattled Penny’s immune system, explaining the reactivation of decades-old varicella-zoster virus. It all added up. Now I could safely skip an imaging study of Penny’s head and diagnostic scrapings of her blisters to rule out the various tropical diseases.

Sure enough, two weeks later, after she completed the antiviral treatment prescribed by her internist, Penny’s lesions were gone. We were both relieved. Without prompt, effective treatment, I estimate that Penny’s chance of complete recovery would have been 50-50 or less. Permanent hearing loss, facial weakness, and ongoing pain are common complications of Ramsay Hunt syndrome. Thankfully, my friend experienced none of these.

Now for the coda.

A Dormant Virus Awakes

As soon as I spied the bubbly patch on the back of my arm, I realized I had a “forme fruste”—another modified version—of shingles.

For one thing, the jangling, electric-shock sensation I had felt two days before was typical of an acutely inflamed nerve. The pièce de résistance was the cluster of blisters atop my skin lesion—the hallmark of varicella-zoster and its close relative, herpes simplex, the virus that causes cold sores and genital herpes.

Most people don’t realize that shingles can present with a subtle footprint, or even with only nerve pain by itself. “Zoster sine herpete” (roughly translated from the Latin, “shingles minus creeping eruption”) is medical lingo for the second syndrome.

In zoster sine herpete, human immune cells quash the virus before it reaches the skin, but not before it infects the nerve. Accordingly, sufferers fail to develop blisters and scabs but still experience the burning spurts of pain associated with full-blown shingles. Proving that varicella-zoster is to blame is not easy. There’s still no simple test for the virus if the patient doesn’t develop lesions, although many doctors know that varicella-zoster virus is one of the leading culprits for such pain.

My patients often ask if a major or minor case of shingles protects them against subsequent outbreaks. Not necessarily, unfortunately; varicella-zoster remains in the body’s cells even after attacks are treated or resolve on their own. Therefore, the shingles vaccine is currently recommended for healthy people over 60 (today, many experts even say over 50), whether or not they have a history of the disease.

I’m a case in point. Will I stick out my arm for the vaccine after reaching age 60? Absolutely.

Claire Panosian Dunavan is a professor of medicine and infectious diseases at UCLA. The cases described in Vital Signs are real, but names and certain details have been changed.