Author:
Daniel F.Leiva
TaranehMatin
AaronHexdall
Description
- Commonly known as shingles and abbreviated HZV
- Incidence of 3-5 per 1,000 person-years; 6-8 per 1,000 person-years in patients 60 or older
- Commonly characterized by unilateral eruption of painful vesicles along a single dermatome although atypical presentations exist including glioma formation
- Increased risk of dissemination, complications, and death in immunocompromised hosts
- Risk factors include:
- Female gender
- White race
- Family history in a dose-dependent manner
- Presence of autoimmune diseases
- Comorbid conditions including CKD, DM, COPD, asthma, depression
- Physical injury
- Statin use
- Increased risk of stroke and myocardial infarction in the 3-12 mo following occurrence due to HZV-induced vasculopathy in those aged >50
Etiology
- Caused by varicella zoster virus (VZV), a dsDNA virus in the Herpesviridae family
- Reactivation of dormant virus in dorsal root, cranial nerve, and autonomic nerve ganglia
- Majority of cases in patients with a history of chickenpox (VZV) but also seen as recurrence from prior vaccination
Pregnancy Prophylaxis |
| HZV during pregnancy is not associated with maternal or obstetric morbidity |
Pediatric Considerations |
| May occur in childhood, most commonly when primary varicella occurred in utero or in the first 6 mo of life |
Signs and Symptoms
- Unilateral dermatomal zoster:
- Prodrome of pain and paresthesia in 75% of patients
- Systemic symptoms may include fever, fatigue, headache
- Pain may be sharp, dull, tingling, burning, or include intense pruritus
- Allodynia may also be present
- Classical rash is maculopapular on erythematous base followed by vesicle formation
- Progresses to scab and crust formation over 7-10 d; crusts fall off in 2-3 wk
- Most common nerve distributions are thoracic and lumbar, followed by trigeminal and cervical
- Less commonly involving multiple adjacent dermatomes or bilateral dermatomes (HZ duplex bilateralis when not symmetric)
- Zoster sine herpete:
- Prodromal phase not followed by rash development
- Increased suspicion in patients who complain of persistent radicular pain
- Herpes zoster ophthalmicus (HZO):
- Involvement of ophthalmic division of trigeminal nerve
- Hutchinson sign - lesion on tip of nose predictive of ocular involvement
- Commonly causes keratitis
- May cause punctate keratitis or corneal pseudodendrites (less ulcerative and less fluorescein uptake than HSV dendrites)
- May lead to acute retinal necrosis, characterized by floaters and painful peripheral vision loss, or progressive outer retinal necrosis with painless vision loss in the latter
- Cranial neuritis:
- Presentation depends on cranial nerve involved
- For example, involvement of cranial nerves III, IV, and VI may present with ophthalmoplegia and ptosis
- For example, Ramsay-Hunt syndrome
- Ramsay-Hunt syndrome:
- A form of cranial neuritis involving cranial nerves VII and VIII
- Lesions in the external auditory canal, peripheral facial palsy, vertigo and anesthesia of anterior 2/3 of hemitongue
- Disseminated disease may cause:
- Myelitis marked by paresis, incontinence of bowel or bladder, or sensory disturbances
- Meningoencephalitis
- Peripheral neuropathy
- Hepatitis, gastritis, and pancreatitis
- Pneumonitis
- Postherpetic neuralgia (PHN)
- Incidence of 8-32% after HZV
- Described as pain that persists at site of zoster lesions for >3 mo after cutaneous disease
- Pain is severe and debilitating and can have a profound impact on quality of life
- Incidence increases with presence of prodromal symptoms, age, severity of HZV, immune suppression, and ophthalmic involvement
Essential Workup
- Clinical diagnosis in the majority of cases
- Labs may aid diagnosis in patients with an atypical presentation especially in immunocompromised hosts
Diagnostic Tests & Interpretation
Lab
- VZV DNA PCR is the gold stand ard:
- From vesicle scraping, blood, saliva, CSF, or BAL
- Can distinguish between HSV and VZV
- Most sensitive and specific
- Tzanck smear:
- Cheap and easy; scrape base of unroofed vesicle
- Multinucleated giant cells with intranuclear inclusion seen on methylene blue, Giemsa, or Wright's stain
- Modified technique can distinguish VZV from HSV
- Low sensitivity
- Serology antibody titers:
- Helpful in CNS vasculopathy as PCR may be negative
- Not sensitive nor specific
- Viral culture:
- 1-2 wk to result
- Specific but not sensitive
Differential Diagnosis
- Primary varicella
- Herpes simplex virus (HSV)
- HSV keratitis
- Conjunctivitis (nonherpetic)
- Trigeminal neuralgia
- Peripheral vertigo
- Migraine headaches
- Cellulitis
- Poison ivy
- Bullous impetigo
- Molluscum contagiosum
- Angina
- Biliary/renal colic
- Appendicitis
- Muscular strain
- Radiculopathy