The Case
It was a long 24-hour shift in a small emergency room in Minas Gerais, Brazil. Emergency departments are the true gateway into the healthcare system — the last resort when outpatient clinics and local health centers have failed to provide answers. And they teach you something new every shift.
Age: ~55-year-old woman • Chief complaint: Sharp chest pain, right side, several days duration
Prior workup: Chest X-ray — clear • Ultrasound — clear • CT scan — clear
Skin examination: No rash, no vesicles, no lesions of any kind
She had already seen other physicians. Multiple imaging studies had been performed and returned completely negative. No organic cause had been found. When she sat across from me, she was clearly in distress — a pained expression, medium-intensity pain, persistent and unexplained.
When I asked her to show me exactly what the pain was like, she made a gesture with her left hand — sweeping from her back, curving around her right side toward the front, following the arc of a rib. A transverse, band-like path. Unilateral.
That gesture told me everything I needed to know.
The Diagnostic Clue: A Gesture Worth a Thousand Lab Results
The pattern of pain she described — unilateral, dermatomal, following the course of a single nerve from the spine outward around the thorax — is the classic presentation of herpes zoster, commonly known as shingles.
But there was a major problem. She had absolutely no skin lesions. No classic vesicular rash. No blisters. No erythema. Nothing visible at all.
The classic shingles rash — vesicles clustered along a dermatome — is what most clinicians look for. Without it, the diagnosis is easily missed. Multiple experienced physicians had already failed to identify her condition. No imaging study will ever show herpes zoster. No routine blood count or urine test will either.
With that classic gesture pattern in mind, I did something every physician should do without shame: I consulted a resource during my shift. I searched "herpes zoster without lesions" — and discovered a well-documented clinical entity called zoster sine herpete.
Zoster Sine Herpete: Shingles That Hides
Sine herpete is Latin for "without herpes" — meaning without the characteristic herpetic rash. In zoster sine herpete, the varicella-zoster virus reactivates, travels along the nerve, and causes pain along the affected dermatome — but never produces visible skin lesions.
Estimated to account for 1–5% of herpes zoster cases. Presents with unilateral dermatomal pain without the vesicular rash. Can be confirmed by PCR detection of VZV DNA in blood, saliva, or cerebrospinal fluid — but the clinical pattern is often sufficient to initiate treatment. Frequently misdiagnosed or diagnosed late.
Understanding the Virus: VZV Biology
Herpes zoster is caused by the varicella-zoster virus (VZV), classified as Human herpesvirus type 3 — one of 8 known human herpesviruses. This is the same virus responsible for chickenpox (varicella) in primary infection.
The Two-Phase Life of VZV
Phase 1 — Primary Infection (Varicella / Chickenpox): The virus enters through the respiratory tract, causes the characteristic generalized vesicular rash of chickenpox, and then heals. Many people — particularly those who had mild childhood infections — barely remember it.
Phase 2 — Latency and Reactivation (Herpes Zoster / Shingles): After primary infection, VZV does not leave the body. It travels along sensory nerves and establishes lifelong latency in the dorsal root ganglia — clusters of nerve cell bodies located near the spine. It can remain dormant for decades, producing no symptoms and no detectable immune response.
Reactivation typically occurs when the immune system's VZV-specific T-cell surveillance weakens. This can happen with age (immunosenescence), physical or emotional stress, illness, immunosuppressive medications, HIV infection, or other immune-depleting conditions. The virus reactivates in the ganglion, travels down the affected nerve, and causes pain and (usually) a localized rash in that nerve's distribution.
Where Shingles Can Appear
Thorax (Most Common)
The majority of herpes zoster cases affect thoracic dermatomes, presenting as a unilateral band of pain and rash wrapping around the chest or back.
Ophthalmic Nerve ⚠️
Herpes zoster ophthalmicus involves the first branch of the trigeminal nerve. Can lead to keratitis, uveitis, and permanent vision loss. Medical emergency.
Face / Trigeminal
Involvement of facial dermatomes. Ramsay Hunt syndrome involves the facial nerve, causing ear pain, facial palsy, and vesicles in the ear canal.
Lumbar / Abdominal
Can mimic appendicitis, diverticulitis, or biliary colic. Unilateral abdominal pain that defies imaging — always consider zoster in the differential.
Classic vs. Atypical Herpes Zoster
| Feature | Classic Herpes Zoster | Zoster Sine Herpete |
|---|---|---|
| Skin rash | Present — vesicular, dermatomal | ❌ Absent |
| Pain | Present, burning, dermatomal | Present, identical distribution |
| Diagnosis | Clinical (pattern + rash) | Clinical + VZV PCR confirmation |
| Imaging | Negative (expected) | Negative (expected) |
| Blood count | Usually normal | Usually normal |
| Treatment | Antiviral + corticosteroid | Antiviral + corticosteroid |
| Miss rate | Low (visible rash) | High (no visible clue) |
Treatment
Standard Treatment for Herpes Zoster (With or Without Lesions)
Acyclovir — first-line antiviral against varicella-zoster virus. Alternatives include valacyclovir and famciclovir (better oral bioavailability, less frequent dosing). Most effective when started within 72 hours of symptom onset.
Corticosteroid — to reduce nerve inflammation and shorten the duration of acute neuritis. May also reduce the risk of post-herpetic neuralgia when used early.
Analgesics appropriate to pain level. Post-herpetic neuralgia (persistent pain after rash resolution) may require gabapentin, pregabalin, or tricyclic antidepressants.
Shingrix vaccine — highly effective (>90%) recombinant zoster vaccine, recommended for adults 50+ regardless of prior shingles history. Two-dose schedule.
The Lesson: Curiosity Is a Clinical Skill
"I don't usually discharge a patient without knowing what they really have. During my shift, I consulted my friend at the time — Google. There wasn't artificial intelligence yet. It's nothing to be ashamed of. We don't know everything."
— Dr. Alberto Saraiva, reflecting on the caseSeveral experienced colleagues had already seen this patient and had not identified the cause. Without the willingness to pause and look something up — during a busy emergency shift, under time pressure — this patient would have received pain medication and been told to return to the clinic. The diagnosis would have been missed again.
This case illustrates two important lessons:
- The history and physical examination remain supreme. The gesture she made — that sweeping, dermatomal arc — contained the diagnosis. No imaging study captured it. No laboratory value revealed it. A careful listener did.
- Intellectual humility and curiosity are clinical tools. Using references, textbooks, search engines, or AI assistance during a consultation is not weakness. It is responsible medicine. Back in residency, we had textbooks that often didn't even describe these atypical presentations. Today's tools are extraordinary — use them.
In any patient presenting with unilateral, dermatomal pain (especially thoracic, lumbar, or facial) that has persisted for days without a clear cause — and where X-ray, CT, and ultrasound are all negative — consider herpes zoster, even without a rash. Think zoster sine herpete. Ask about prior chickenpox. Ask about immune status. Treat empirically with antivirals if clinical suspicion is high.
References
- Cohen JI. Clinical practice: Herpes zoster. N Engl J Med. 2013;369(3):255-263.
- Levin MJ, Oxman MN. Varicella and Zoster. In: Mandell, Douglas and Bennett's Principles and Practice of Infectious Diseases. 9th ed. 2020.
- Gilden D, Cohrs RJ, Mahalingam R, Nagel MA. Varicella zoster virus vasculopathies: diverse clinical manifestations, laboratory features, pathogenesis, and treatment. Lancet Neurol. 2009;8(8):731-740.
- Schmader KE, Oxman MN. Varicella and Herpes Zoster. In: Fitzpatrick's Dermatology. 9th ed. McGraw-Hill. 2019.