Herpes zoster
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Background
- Also known as shingles
- Caused by varicella zoster virus (VZV; also known as Human Herpes Virus 3) causing Varicella (chicken pox) and later zoster (shingles)
- Virus is dormant in dorsal root ganglion and reactivates causing characteristic vesiculopapular rash in dermatomal distribution
- Occurs once immunity to virus declines (elderly, immunosuppressed, post transplant, HIV)
Prevention
- Patient is contagious until lesions are crusted over
- Consider varicella-zoster immunoglobulin to immunosupressed, pregnant, neonate contacts
- Zoster vaccination if >60
Herpes Virus Types
- HHV-1: Herpes Simplex Virus-1
- HHV-2: Herpes Simplex Virus-2
- Herpes B virus
- Varicella zoster virus
- Varicella (Chickenpox)
- Herpes zoster (Shingles)
- Herpes zoster ophthalmicus
- Herpes zoster oticus (Ramsay Hunt syndrome)
- HHV-6 (Roseola infantum)
- HHV-8 (Kaposi’s sarcoma)
- Epstein-Barr virus
- Cytomegalovirus
Clinical Features
- Prodrome: Headache, malaise, photophobia
- Antecedent pruritus, paresthesia, pain to dermatome 2-3 days prior to rash
- Maculopapular rash (see below) progresses to vesicles, may coalesce to bullae, in dermatomal distribution lasting 10-15 days
- Does not cross midline
- Typically affects chest/face
- Lumbar and sacral dermatomes may display skin sparing between the feet and groin
- V3 involvement can present initially as dental pain
Differential Diagnosis
Vesiculobullous rashes
Febrile
- Diffuse distribution
- Varicella (chickenpox)
- Smallpox
- Monkeypox
- Disseminated gonococcal disease
- DIC
- Purpural fulminans
- Localized distribution
Afebrile
- Diffuse distribution
- Bullous pemphigoid
- Drug-Induced bullous disorders
- Pemphigus vulgaris
- Phytophotodermatitis
- Erythema multiforme major
- Bullous impetigo
- Localized distribution
- Contact dermatitis
- Herpes zoster (shingles)
- Dyshidrotic eczema
- Burn
- Dermatitis herpetiformis
- Erythema multiforme minor
- Poison Oak, Ivy, Sumac dermatitis
- Bullosis diabeticorum
- Bullous impetigo
- Folliculitis
Varicella zoster virus
- Varicella (Chickenpox)
- Herpes zoster (Shingles)
- Herpes zoster ophthalmicus
- Herpes zoster oticus (Ramsay Hunt syndrome)
Evaluation
Workup
- Generally a clinical diagnosis
- May consider viral Culture, antigen, PCR of vesicle fluid
Evaluation
- Confirm that the patient does not have:
- Herpes zoster ophthalmicus
- Herpes zoster oticus (Ramsay Hunt syndrome)
- Consider further evaluation for immunocompromized state (may be initial presentation of HIV) if:
- Disseminated
- For skin disseminated is 3 or more dermatomes affected.
- Can also disseminate to other organs including liver, lung, and brain.
- Atypical illness/severe disease
- Disseminated
- In immunocompromised patients consider further evaluation for:
- Pneumonitis
- Hepatitis
- Encephalitis
Management
Analgesia
- Analgesia is very important and should be prescribed along with an antiviral
- Consider lidocaine patch, NSAIDS, oral opioids, or gabapentin
- Diphenhydramine and ranitidine for itch/pain
Antivirals
- Reduces risk/duration of postherpetic neuralgia with dosing based on immune status and time course of disease
- Not effective in treating postherpetic neuralgia once it has developed
Immunocompetent patients:
- Acyclovir 800mg PO 5x/day x 7d if <72hr of onset of rash or >72hr if new vesicles present/developing[1]
- Valacyclovir (can also be given but is generally more expensive than acyclovir)
- 1g PO q8hrs (CrCl normal)
- 1g PO q12hrs (CrCl 30-49 mL/min)
- 1g PO q24hrs (CrCl 10-29 mL/min(
- 500mg q24hrs PO (CrCl < 10ml/min)
Immunosuppressed patients:
- Antiviral therapy should be given regardless of the time of onset of rash
- Acyclovir 10mg/kg IV q8h OR 800mg PO 5x/day x 7d or Foscarnet for acyclovir-resistant VZV, disseminated zoster, CNS involvement, ophthalmic involvement, advanced AIDS, or recent transplant
- Isolation precautions
- Disseminated zoster requires airborne precautions
Glucocorticoids
- Steroids not shown to be beneficial[2]
Disposition
- Admit for disseminated VZ, CNS involvement, severely immunosuppressed
- Healing of lesions may take 4 or more weeks[3]
Complications
- Postherpetic Neuralgia (risk increases with age)
- Cellulitis
- Impetigo
- Necrotizing Fasciitis
- SIADH
See Also
- Herpes zoster ophthalmicus
- Herpes zoster oticus (Ramsay Hunt syndrome)
- Generalized rashes
References
- ↑ Cohen, J. Herpes Zoster. N Engl J Med 2013; 369:255-263. DOI: 10.1056/NEJMcp1302674
- ↑ He L, Zhang D, Zhou M, Zhu C. Corticosteroids for preventing postherpetic neuralgia. Cochrane Database Syst Rev. 2008.
- ↑ Sampathkumar P, et al. Herpes zoster (shingles) and postherpetic neuralgia. Mayo Clin Proc. 2009; 84(3):274–280.