Shingles

Shingles (Herpes Zoster): Comprehensive Guide for Healthcare Professionals and Patients

1. Introduction

  • Definition: Shingles, or herpes zoster, is a viral infection caused by the reactivation of the varicella-zoster virus (VZV), the same virus responsible for chickenpox. It presents as a painful, blistering rash, often localised to a single dermatome.
  • Epidemiology: Shingles affects approximately 1 in 3 individuals in their lifetime, with increased prevalence in individuals over 50 and those with weakened immune systems.
  • Significance: Shingles can lead to severe complications like postherpetic neuralgia (PHN), particularly in older adults, significantly affecting quality of life.

2. Causes and Risk Factors

  • Causes:
    • Reactivation of latent varicella-zoster virus in dorsal root ganglia.
  • Risk Factors:
    • Age >50 years.
    • Immunosuppression (e.g., HIV, chemotherapy, organ transplantation).
    • Stress or trauma.
    • Chronic conditions like diabetes or autoimmune diseases.

3. Pathophysiology

  • After primary infection with varicella (chickenpox), the virus remains dormant in sensory nerve ganglia. Reactivation occurs due to weakened immune surveillance, causing viral replication and inflammation in the affected nerve, resulting in a painful rash.

4. Symptoms and Features

  • Early Symptoms (prodromal phase):
    • Pain, itching, or tingling in a localised area (dermatome).
    • Fever, headache, and malaise.
  • Acute Symptoms:
    • Red, blistering rash typically confined to one dermatome, often on the torso or face.
    • Blisters that crust over in 7–10 days.
  • Severe Cases:
    • Eye involvement (herpes zoster ophthalmicus), which can threaten vision.
    • Ramsay Hunt syndrome: Facial paralysis and ear pain due to cranial nerve VII involvement.

5. Complications

  • Postherpetic Neuralgia (PHN): Persistent pain lasting >3 months after the rash resolves.
  • Vision Loss: Due to herpes zoster ophthalmicus.
  • Neurological Complications: Meningitis, encephalitis, or myelitis.
  • Secondary Bacterial Infection: Of the skin lesions.

6. Diagnosis

  • Clinical Features: Diagnosis is typically clinical based on a characteristic dermatomal rash and history of chickenpox.
  • Laboratory Tests:
    • Polymerase chain reaction (PCR) to detect VZV DNA in vesicular fluid (if diagnosis is unclear).
    • Direct fluorescent antibody (DFA) test.

7. Management Overview

  • Goals: Reduce viral replication, alleviate symptoms, and prevent complications like PHN.
  • Approach: Antiviral therapy, pain management, and vaccination to prevent recurrence.

8. Treatment Options with Cost (USD)

  • Antiviral Medications:
    • Acyclovir: ~$10–$30 per course.
    • Valacyclovir: ~$50–$100 per course.
    • Famciclovir: ~$50–$120 per course.
  • Pain Relief:
    • NSAIDs or acetaminophen: ~$5–$20 per pack.
    • Topical lidocaine patches: ~$20–$40 per box.

9. Advanced Treatment Options with Cost (USD)

  • Severe or Refractory Cases:
    • Corticosteroids (short course): ~$10–$30.
    • Gabapentinoids (e.g., gabapentin or pregabalin) for PHN: ~$30–$100/month.
  • Vaccination:
    • Recombinant zoster vaccine (Shingrix): ~$300–$400 for the full two-dose series.

10. Pharmacological Treatment

  • First-line: Oral antiviral therapy (acyclovir, valacyclovir, or famciclovir) started within 72 hours of rash onset to reduce severity and duration.
  • Adjunctive: Analgesics and topical agents for pain relief.
  • Preventive: Shingrix vaccination for individuals >50 or immunocompromised patients.

11. Medication Tables

Table 1: Doses and Side Effects

DrugIndicationDoseCommon Side Effects
AcyclovirAntiviral therapy800 mg 5 times/day for 7 daysNausea, headache, kidney toxicity
ValacyclovirAntiviral therapy1 g 3 times/day for 7 daysNausea, abdominal pain, fatigue
FamciclovirAntiviral therapy500 mg 3 times/day for 7 daysDizziness, headache, diarrhoea
GabapentinPostherpetic neuralgia300–3,600 mg/dayDrowsiness, dizziness, weight gain
Lidocaine patchesLocalised pain reliefApply for up to 12 hours/daySkin irritation, redness

Table 2: Brand Names and Approximate Costs (USD)

DrugBrand NamesApprox. Cost
AcyclovirZovirax$10–$30 per course
ValacyclovirValtrex$50–$100 per course
FamciclovirFamvir$50–$120 per course
GabapentinNeurontin$30–$100 per month
Lidocaine patchesLidoderm$20–$40 per box

12. Lifestyle Interventions

  • Keep the rash clean and dry to prevent secondary bacterial infection.
  • Avoid close contact with immunocompromised individuals, pregnant women, or unvaccinated children until lesions have crusted over.
  • Reduce stress and improve sleep hygiene to support immune function.

13. Monitoring Parameters

  • Assess for resolution of the rash and pain.
  • Monitor for complications such as PHN or secondary infections.
  • Screen for side effects of antivirals and other medications.

14. Patient Counseling Points

  • Educate on the importance of starting antiviral therapy within 72 hours of rash onset.
  • Explain that pain may persist after the rash resolves (PHN) and discuss treatment options.
  • Reassure that shingles is not contagious but can cause chickenpox in unvaccinated individuals.
  • Discuss the benefits of vaccination in preventing shingles recurrence and complications.

15. Special Populations

  • In Children: Shingles is rare in children but may occur in those with prior varicella infection or immunosuppression; antiviral treatment is similar to adults but weight-adjusted.
  • In Pregnancy: Antiviral therapy (acyclovir or valacyclovir) is generally safe; ensure monitoring for complications.
  • In Elderly: Higher risk of complications like PHN; vaccination is strongly recommended.

16. Prevention

  • Vaccination with Shingrix for individuals aged 50 and above, and immunocompromised patients.
  • Maintain a healthy lifestyle to support immune function.
  • Prompt treatment of varicella infections in childhood to reduce the risk of later reactivation.

17. FAQs

  1. What is shingles?
    Answer: A viral infection caused by the reactivation of the varicella-zoster virus, leading to a painful rash.
  2. What causes shingles?
    Answer: Reactivation of the varicella-zoster virus, often triggered by weakened immunity.
  3. How is shingles treated?
    Answer: Antiviral therapy (e.g., acyclovir) and pain management.
  4. Is shingles contagious?
    Answer: Shingles itself is not contagious, but the virus can cause chickenpox in unvaccinated individuals.
  5. Can shingles recur?
    Answer: Yes, though recurrence is uncommon; vaccination reduces the risk.
  6. What is postherpetic neuralgia?
    Answer: Persistent nerve pain lasting >3 months after the shingles rash resolves.
  7. Who should get the shingles vaccine?
    Answer: Adults aged 50+ and immunocompromised individuals.
  8. How long does shingles last?
    Answer: The rash typically resolves within 2–4 weeks.
  9. Can stress cause shingles?
    Answer: Stress can weaken the immune system, increasing the risk of reactivation.
  10. Are there complications of shingles?
    Answer: Yes, including PHN, vision loss, and secondary infections.
  11. How can I prevent shingles?
    Answer: Vaccination with Shingrix is the best prevention.
  12. Can shingles affect the eyes?
    Answer: Yes, herpes zoster ophthalmicus can lead to vision loss if untreated.
  13. What does the shingles vaccine do?
    Answer: It reduces the risk of shingles and its complications, such as PHN.
  14. When should I see a doctor for shingles?
    Answer: Immediately upon noticing the rash or nerve pain.
  15. Is shingles more common in older adults?
    Answer: Yes, due to age-related decline in immunity.