Varicella Zoster Flashcards
Define Varicella Zoster?
Primary infection is called varicella (chickenpox)
Reactivation of the dormant virus (found in dorsal root ganglia) causes zoster (shingles)
What is Varicella Zoster also known as?
Herpes Zoster
What is the aetiology of Varicella Zoster?
VZV is a herpes ds-DNA virus
Highly contagious
Transmission by aerosol inhalation or direct contact with vesicular secretions
What is the epidemiology of Varicella Zoster?
Chicken pox peak incidence: 4-10 yrs
Shingles peak incidence: > 50 yrs
90% of adults are VZV IgG positive
What are the presenting symptoms of Chickenpox?
Prodromal Malaise
Mild Pyrexia
Sudden apperance of intensely itchy spreading rash mainly affecting face and trunk
Vesicles weep and crust over
New vesicles appear
Contagious from 48 hrs before the rash until after the vesicles have all crusted over (7-10 days)
What are the presenting symptoms of Shingles?
May occur after a period of stress
Tingling/hyperaesthesia in a dermatomal distribution
Painful skin lesions
Recovery: 10-14 days
Why is it a Dermatomal Distribution for Shingles tingling?
Dermatomal because the rash remains dormant in the dorsal root ganglia and reactivation makes the virus travel down the sensory axon to produce a dermatomal shingles rash
What are the signs of Chickenpox on physical examination?
Maculopapular rash
Areas of weeping and crusting
Skin excorciation (from scratching)
Mild pyrexia
What are the signs of Shingles on physical examination?
Vesicular maculopapular rash
Dermatomal Distribution
Skin Excoriation
What investigations would you do for Varicella Zoster?
Usually CLINICAL diagnoses
Vesicle fluid may be sent for electron microscopy viral PCR (RARELY necessary)
Chicken pox in an adult with previous history of varicella infection may require HIV testing
What is the management plan for Chickenpox?
Children - treat symptoms
Adults - consider aciclovir
What is the management plan for Shingles?
Aciclovir
Valaciclovir
Famciclovir
What is the prevention for Varicella Zoster?
Varicella Zoster Ig (VZIG) - may be considered in immunosuppressed or pregnant
What are the possible complications for Chickenpox?
Secondary Infection Scarring Pneumonia Encephalitis Congenital Varicella Syndrome
What is the possible complications of Shingles?
Postherpetic neuralgia Zoster ophthalmicus Ramsey-Hunt Syndrome Sacral Zoster Motor Zoster
