Herpes Zoster (Shingles) — Left Abdominal Region, Above the Umbilicus, in a 70-Year-Old Man

Fig. 19.16 — Classic herpes zoster dermatomal eruption on the torso (Andrews' Diseases of the Skin)

Dermatome Involved

Pathophysiology

• Comorbidities (diabetes, COPD, autoimmune disease)
• Statin use (slightly increased risk)
• Hemodialysis
• Malignancy (especially hematologic) — zoster patients have a 0.7–1.8% absolute risk of a new cancer diagnosis within 1 year

Clinical Features

Complications — High Priority in a 70-Year-Old

1. Postherpetic Neuralgia (PHN) — Most Important

• Occurs in up to 40% of patients over age 60 (vs. <10% under age 60)
• Pain persists after skin lesions heal, driven by incomplete nerve injury creating a hyperpathic state
• Can last months to years; eventually subsides even in severe cases

2. Other Complications

• Disseminated zoster: >20 satellite lesions outside the dermatome → risk of visceral (lung, liver, CNS) spread; more common in immunosuppressed/elderly
• Bacterial superinfection of skin lesions
• Although not relevant here, ophthalmic (V1) and Ramsay Hunt syndrome (cranial nerve VII) are the most feared cranial nerve variants

Management

Antiviral Therapy (Start Immediately)

• Antivirals hasten lesion resolution, reduce viral shedding, and decrease acute pain
• Treatment up to 7 days after onset is still beneficial if new vesicles are still forming
• IV acyclovir is reserved for disseminated disease, CNS involvement, or severely immunosuppressed patients

Pain Management

• Acetaminophen / NSAIDs for mild-moderate pain
• Opioid analgesia may be required for severe acute pain
• Corticosteroids (in combination with antivirals): modest reduction in acute pain; do not prevent PHN but can be considered in older individuals with severe pain without contraindications
• Cool compresses for local relief

Postherpetic Neuralgia Treatment (if it develops)

• Tricyclic antidepressants (amitriptyline 50–125 mg at bedtime) — well-established, first-line
• Gabapentin / Pregabalin — FDA-approved for PHN; particularly effective for lancinating-type pain
• Capsaicin ointment — topical, applied to the affected skin
• Carbamazepine, valproate, SSRIs — adjunctive options
• Nerve blocks — inconsistent benefit but may offer temporary relief
• Short-term narcotics are appropriate for severe persistent pain; patients with >1 year of symptoms often have a depressive component and respond to antidepressants

Vaccination — Prevention

• Shingrix (recombinant zoster vaccine, RZV) is the current preferred vaccine — recommended for all immunocompetent adults ≥50 years (2 doses)
• The older live vaccine (Zostavax) decreased burden of illness by 61% and PHN by 67% in clinical trials; Shingrix is substantially more effective
• The vaccine is not contraindicated in someone who has already had zoster

Red Flags to Rule Out in This Patient

1. Disseminated zoster — check for >20 lesions outside the T8–T10 dermatome
2. Visceral involvement — unexplained respiratory symptoms warrant a chest X-ray
3. New underlying malignancy — consider workup given the 0.7–1.8% 1-year cancer risk post-zoster, especially hematologic malignancy
4. CNS involvement — any encephalopathic features warrant MRI brain, lumbar puncture, and CSF VZV PCR

Managing Itch (Pruritus) in Herpes Zoster

Why It Itches

Oral Antihistamines (Systemic Itch Relief)

In a 70-year-old, hydroxyzine (low dose, 10–25 mg at bedtime) or cetirizine/loratadine during the day is the safest choice. Avoid diphenhydramine as the first-line choice in elderly patients.

Topical Treatments (Local Skin Relief)

For the Vesicular/Weeping Phase (Active Blisters)

Do NOT apply calamine or any lotion directly on open/broken skin erosions — use wet compresses (Burrow's) there instead.

Once Lesions Begin Crusting / Healing Phase

What NOT to Apply

• Topical acyclovir cream — no benefit for shingles (it works systemically; topical preparations do not meaningfully penetrate)
• Topical steroids — avoid directly on vesicular/active lesions; can worsen infection
• Antibiotic ointments (e.g., neomycin, bacitracin) — only if secondary bacterial infection is suspected

Practical Prescription Summary for This Patient

1. Oral: Hydroxyzine 10–25 mg at bedtime (for itch + sleep)
         + Cetirizine 10 mg every morning (daytime itch)

2. Topical (acute/weeping phase):
   - Calamine lotion — apply with cotton ball TID–QID to intact vesicles
   - Burrow's solution compresses — for oozing/weeping areas, 15 min TID

3. Topical (healing/post-crusting phase):
   - Lidocaine 2% gel — apply to painful itchy areas as needed
   - White soft paraffin — over dried crusts to prevent cracking

4. General: Cool compresses (wet cloth, 20 min), loose cotton clothing,
   colloidal oatmeal baths

Important Reminders

• Ensure the oral antiviral (valacyclovir/famciclovir) has been started — this is the primary treatment and will reduce the duration of itch along with the rash
• If itch is neurogenic (persists after lesions heal = PHN-related itch), gabapentin or pregabalin is the appropriate agent — antihistamines will not work for neurogenic itch
• Keep nails short and advise against scratching to prevent bacterial superinfection