Clinical Background
Varicella-zoster virus (VZV) is the cause of chickenpox in children and shingles in adults.
Epidemiology
- Incidence - estimated 1 million new cases annually in the U.S.
- Age
- Varicella - children
- Herpes zoster - >60 years
- Gender - equal distribution
Risk Factors
- For non-immune individuals, direct contact with large-particle droplets
- Risk factors include immune deficiency conditions, psychological stress and localized physical trauma
Organism
- DNA virus
- Member of the Herpesviridae family
- Adult infection usually the result of reactivated latent infection of sensory ganglia
Clinical Presentation
- Varicella
- Fever and generalized exanthem
- Herpes zoster
- Characterized by:
- Skin eruption
- Unilateral maculopapular lesions followed by vesicular eruptions with dermatomal distribution
- Facial nerve (7th cranial nerve) involvement (Ramsey-Hunt syndrome)
- Pain from inflammation of sensory nerve ganglia
- May mimic other serious medical conditions such as myocardial infarction, appendicitis, acute cholecystitis, renal colic, pulmonary embolism or glaucoma
- Lesson common manifestations include pneumonitis, acute retinal necrosis, myelitis, vasculopathy, hepatitis and meningoencephalitis
- Complications
- Postherpetic neuralgia
- Secondary skin infection from Streptococcus pyogenes or S. aureas
- Congenital infection - congenital VZV transmission may cause severe disseminated neonatal infection with:
- Pneumonia
- Skin lesions
- Hemorrhages
- Death
- Skin eruption
- Characterized by:
Treatment
- Early treatment of zoster accelerates resolution and perhaps lessens post-herpetic pain
Prevention
- Childhood vaccination preventive for VZV in most cases
- Universal vaccination has decreased outbreaks and severity of secondary complications
- New vaccine recently approved for adults >60 years to prevent herpes zoster
- Vaccine shown to reduce the incidence of PHN by 66.5%
See Also
