1. Dr hab. n. med. Ewa Majda-Stanislawska
Varicella Chickenpox
Dr hab. n. med. Ewa Majda-Stanislawska

2. Varicella-zoster virus (VZV)
causes two distinct clinical diseases:
1. Varicella, more commonly called chickenpox:
is the primary infection
results from exposure of a person susceptible
to the virus
2. Herpes zoster is due to the recurrence of infection
is more localized
often referred to as shingles,
is a common infection among the elderly.

3. Shingles has been recognized since ancient times
as a unique clinical entity because of the dermatomal vesicular rash
Chickenpox was often confused with smallpox

4. VZV is a member of the Herpesviridae family
The virus has icosapentahedral symmetry
It contains centrally located double-stranded DNA
with a surrounding envelope.
Only enveloped virions are infectious;
this may account for the lability of VZV.
The envelope is sensitive to detergent, ether, and air drying.

5. Humans are the only known reservoir for VZV.
Chickenpox is a common infection of childhood
and affects both genders equally and people of all races.
It becomes epidemic among susceptible persons during
seasonal periods:
late winter and early spring
close contact appears to be the key determinant for transmission

6. occur in children younger than 13 years
90% of cases
occur in children younger than 13 years
Approximately 10% of persons older than 15 years
are considered susceptible to VZV infection.
The incubation period of chickenpox
is generally regarded to be 14 to 15 days,
but disease can appear within a range of 10 to 20 days

7. Infectivity Patients are infectious for a period of approximately
48 hours before the period of vesicle formation
for 4 to 5 days thereafter until all vesicles are crusted.

8. Herpes zoster VZV characteristically becomes latent
after primary infection within the dorsal root ganglia.
Reactivation leads to herpes zoster, a sporadic disease.
Herpes zoster is a disease that occurs at all ages,
but it afflicts about 20% or more of the population overall,
mainly the elderly.

9. Herpes zoster, occurs in persons who are seropositive for VZV or,
more specifically, in those who have had chickenpox.
Reactivation appears to be dependent on a balance
between virus and host factors
Persons who are immunocompromised
have a higher incidence of both chickenpox and shingles.
Herpes zoster occurs within the first 2 years of life in children
born to women who have had chickenpox during pregnancy.
These cases probably reflect in utero chickenpox with reactivation early in life.

10. Mortality rate of varicella
There have been approximately 250 deaths per year
in the USA.
For the normal child, chickenpox-associated mortality
is less than 2 per 100,000 cases.
This risk increases by more than 15-fold for adults

11. Manifestations of chickenpox are a rash, low-grade fever, and malaise.
A prodrome of symptoms may occur 1 to 2 days
before the onset of the exanthem in a few patients.
For the most part, chickenpox in the immunocompetent child
is a benign illness associated with a temperature of oC
of 3 to 5 days' duration

12. The skin manifestations
consist of maculopapules, vesicles,
and scabs in varying stages of evolution.
The lesions initially contain clear vesicular fluid,
over a very short period of time they pustulate and scab.
Most lesions are small,
having an erythematous base
with a diameter of 5 mm to as large as 12 to 13 mm.

13. The lesions can be round or oval;
central umbilication occurs as healing progresses.
If they do not rupture within a few hours,
the contents rapidly become purulent in appearance.
The lesions appear on the trunk and face,
and rapidly spread centrifugally
to involve other areas of the body.
Successive crops of lesions generally appear
over a period of 2 to 4 days.

14. Early in the disease, the hallmark of the infection
is the appearance of lesions at all stages
The lesions can also be found on the mucosa of the oropharynx
and even the vagina.
The crusts completely fall off
within 1 to 2 weeks after the onset of infection
and leave a slightly depressed area of skin.

15. Complications - skin bacterial superinfection:
often due to gram-positive organisms.
Streptococcal toxic shock is a rare
but potentially lethal complication of varicella.
infection in the neutropenic host can be systemic.

16. Complications - CNS involvement
acute cerebellar ataxia or encephalitis.
Cerebellar ataxia has been estimated to occur in 1 in 4000 cases among children younger than 15 years.
It can appear as late as 21 days after the onset of rash.
Usually it presents within 1 week of the onset of the exanthem.

17. Cerebellar ataxia - symptoms
vomiting,
altered speech,
fever,
vertigo,
tremor.
Cerebrospinal fluid (CSF) demonstrates lymphocytosis
and elevated levels of protein.

18. Complications - encephalitis
Encephalitis is reported to occur in 0.1% to 0.2%
of persons with the disease.
It is characterized by depression in the level of consciousness
with progressive headaches,
vomiting,
altered thought patterns,
fever,
frequent seizures.
The duration of disease in these patients is at least 2 weeks.
Some patients experience progressive neurologic deterioration
that leads to death.
Mortality in patients who develop encephalitis has been estimated
to range between 5% and 20%,
neurologic sequelae occur in as many as 15% of survivors.

19. Complications - varicella pneumonitis
Occurs more commonly in adults and in immunocompromised persons
It appears 3 to 5 days into the course of illness
I is associated with:
tachypnea,
cough,
dyspnea,
fever.
Chest radiographs usually reveal nodular or interstitial pneumonia.
Varicella pneumonitis can be life threatening
when it occurs in pregnant women during the second or third trimester

20. Primary viral pneumonia in varicella

21. Perinatal varicella high death rate when maternal disease develops:
5 days before delivery
or up to 48 hours postpartum.
This is the consequence of the newborn
failing to receive protective transplacental antibodies
as well as the immaturity of the neonatal immune system.
The mortality has been reported to be as high as 30%.
Affected children have progressive disease involving visceral organs, especially the lung.

22. Congenital varicella, rather uncommon, Characterized by:
skin scarring,
hypoplastic extremities,
eye abnormalities,
evidence of CNS impairment

23. Varicella has been associated epidemiologically
with the development of Reye's syndrome
and coadministration of aspirin
Therefore, the administration of aspirin
is contraindicated in persons with varicella.

24. The diagnosis of both chickenpox and shingles
is usually made by history and physical examination

25. Treatment The medical management of chickenpox and shingles
in the normal host is directed toward reduction of complications.
For chickenpox, hygiene is important:
bathing,
astringent soaks,
closely cropped fingernails
to avoid a source for secondary bacterial infection
associated with scratching of the pruritic skin lesions. .

26. Oral treatment with Acyclovir
In normal children, adolescents, and adults
shortens the duration of lesion formation by about 1 day,
reduces the total number of new lesions by approximately 25%,
diminishes constitutional symptoms in one third of patients.
Therapy for high-risk groups of patients:
premature infants,
children with bronchopulmonary dysplasia
within 24 hours of onset of disease.
In children 2 to 16 years old, the oral dosage is 20 mg/kg
4 times daily for 5 days (maximum of 800 mg daily).
Adolescents and adults can receive up to 800 mg 5 times a day.

27. Parenteral treatment with Acyclovir
The recommended dosage is from 5 to 10 mg/kg
administered intravenously every 8 hours
or, as suggested by some, 500 mg/m2 intravenously every 8 hours,
especially for children.
Indications:
immunocompromised host,
neurological complications.
pneumonitis