Transcript Varicella, commonly known in the United States as Chickenpox

In The
Name of
God
Background:
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Varicella, commonly known in the
United States as Chickenpox
Varicella-zoster virus.
Generally is a mild self-limiting viral
illness with occasional complications
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varicella is not totally benign
A recent study : 1 in 50 cases are
associated with complications
most dreaded are varicella
pneumonia and encephalitis
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The vaccination against varicella in
1995, which reduced morbidity
and mortality
Varicella is common and highly
contagious
and
nearly
all
susceptible children affects before
adolescence.
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Household Transmission rates are
80-90%
Second Cases often are more severe
Maximum Transmission late winter
and spring.
Pathophysiology:
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The varicella-zoster virus enters
through the respiratory system and
colonizes the upper respiratory tract
The virus initially replicates in the
regional lymph nodes,the spleen, liver,
and ....
Frequency:
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Internationally: Varicella affects
nearly all children who do not have
immunity. Annual incidence is
estimated at 80-90 million cases.
Mortality/Morbidity:
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In healthy children aged
1-14 years, the mortality
rate is estimated at 2
deaths per 100,000 cases.
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Most deaths :
encephalitis, pneumonia, secondary
bacterial infection, and Reye syndrome.
The disease can be serious in neonates,
depending on the timing of infection in
the mother.
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Race: Varicella has no racial
predilection.
Sex: Varicella has no sex predilection.
Age: Maximum incidence of varicella is
in children aged 1-6 years
Persons older than 14 years account
for 10% of varicella cases.
CLINICAL
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History:
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Exposure
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Varicella spreads primarily by airborne
Respiratory droplets.
Most patients have a History of Exposure
in the home, daycare center, or school.
Varicella's incubation period typically is
10-14 days, it may to 21 days.
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Prodrome
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Low-grade fever preceding skin manifestations by
1-2 days
Complaints of abdominal pain by some children
Rash, usually starting on the head and trunk and
spreading to the rest of the body
intense pruritus
Headache
Malaise
Anorexia
Cough and coryza
Sore throat
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Physical:
Rash
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healthy child usually has 250-500 lesions but may
have as few as 10 or as many as 1500.
starts as a red macule and passes through stages
of papule, vesicle, pustule, and crust.
Redness or swelling around a lesion should lead to
suspicion of bacterial superinfection.
Varicella's hallmark is the simultaneous presence
of different stages of the rash.
Some lesions may appear in the oropharynx.
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Eye lesions are rare.
New lesions continue for 3-5 days.
Lesions usually crust by 6 days (2- to 12-d
range), and heal completely by 16 days (7to 34-d range).
Prolonged eruption of new lesions or
delayed crusting and healing can occur
with impaired cellular immunity.
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Fever
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Fever usually is low-grade but occasionally
may be high
healthy children, fever typically subsides
within 4 days.
Prolonged fever should prompt suspicion of
complication or immunodeficiency.
Outcomes :
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Congenital varicella syndrome
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Congenital varicella syndrome occurs in 2% of
children born to women who develop varicella
during
Fetal injury risk is unrelated to the severity of
disease in the mother.
Zoster exposure during pregnancy has not
been associated with fetal injury.
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Infantile zoster :
Infantile zoster usually manifests within
the first year.
The cause is maternal varicella infection
after the 20th week of gestation.
Infantile zoster commonly involves the
thoracic dermatomes.
Transmission
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Transmission occurs mainly by respiratory droplets
containing the virus, making the disease highly
contagious even before the rash appears.
Papules and vesicles, have high populations of the
virus.
Varicella's infectious period begins 2 days before
skin lesions appear and ends when the lesions
crust.
Direct person-to-person contact with lesions also
spreads the virus.
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Risk factors for severe varicella
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A neonate's first month of life, especially if
the mother is seronegative.
Delivery before 28 weeks of gestation
Adolescence and adulthood
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Steroid therapy: High doses (1-2
mg/kg/d of prednisolone) for 2
weeks. Even short-term therapy
Malignancy: The risk is highest for
children with leukemia. Almost 30%
of patients who are
immunocompromised
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Immunocompromised state (eg,
malignancy, antimalignancy drugs, HIV,
other congenital or acquired
immunodeficient conditions(
Pregnancy:, especially pneumonia.
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DIFFERENTIALS
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Drug reactions
Insect bites
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WORKUP
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Lab Studies:
unnecessary for diagnosis because
varicella is obvious clinically.
Most children with varicella have
leukopenia in the first 3 days, followed
by leukocytosis.
Marked leukocytosis may indicate a
secondary bacterial infection
Most children with significant secondary
bacterial infections do not have
leucocytosis.
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Imaging Studies:
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Chest x-ray
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Children with high temperatures and respiratory
signs should have a chest x-ray to confirm or
exclude pneumonia.
Chest x-ray findings may be normal or may show
diffuse bilateral nodular infiltrates in primary
varicella pneumonia.
X-rays also may detect of secondary bacterial
pneumonia.
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Other Tests:
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Lumbar puncture
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Children with neurological signs should have their
(CSF) examined.
The CSF of varicella encephalitis may have few or
as many as a hundred cells that are
polymorphonuclear or mononuclear, depending on
the timing of the lumbar puncture.
Glucose levels are normal.
Protein levels are normal or slightly
raised.
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TREATMENT
Medical Care:
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Manage
Pruritus
with
cool
compresses and regular bathing.
Trimming the child's Fingernails and
having the child wear mittens while
sleeping may reduce scratching.
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Consultations:
Consult with an infectious disease specialist in the
following situations:
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Progressive or severe varicella
Life-threatening complications (eg, encephalitis, pneumonia)
Serious secondary bacterial infections, especially group A
streptococcal superinfections, which may evolve rapidly into
necrotizing fasciitis and toxic shock syndrome
Children who develop severe and life-threatening
varicella complications may require hospitalization in
an ICU
Diet:
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full and unrestricted diet to the child.
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take sufficient fluids to maintain hydration.
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Adequate hydration is especially important if
the child is receiving acyclovir
Activity:
No activity restrictions are needed for young
children with uncomplicated varicella.
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MEDICATION
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Antivirals -- Chickenpox is not always
benign.
Antiviral drugs are recommended for
adolescents, adults, and children on
steroid or salicylate therapy and for
children who are immunocompromised.
Acyclovir is the only adequately studied
drug of this class.
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Antipyretics -- Fever usually is low grade but may
be elevated.
Acetaminophen probably is the safest drug to use
for this purpose.
Salicylate usage for varicella is associated with Reye
syndrome
(NSAIDs) have been suspected of suppressing
immune function and promoting infection progress in
patients infected with invasive group A streptococci.
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FOLLOW-UP
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Further Inpatient Care:
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Indications for admission to ICU/neonatal ICU
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Altered consciousness
Seizures
Difficulty walking
Respiratory distress
Cyanosis
Low oxygen saturation
Hospitalize and treat all newborns whose
mothers developed varicella less than 5 days
before or within 2 days after delivery.
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Prevention:
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Vaccination
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Varicella vaccine consists of live attenuated. The vaccine is
safe and highly immunogenic.
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Protection from 71-100% and is likely to be long term.
Breakthrough varicella is mild when it occurs.
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The vaccine is effective when administered on or after the
age of 1 year. Only a single dose is recommended for
children younger than 13 years. For older children, the
recommended dosage is 2 doses separated by 4-8 weeks.
Postexposure prophylaxis, if provided within 72 hours of
contact, can prevent or attenuate disease in the exposed
individual.
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Varicella-zoster immune globulin
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VZIG is used as postexposure prophylaxis in highrisk individuals. Administration as soon as possible
after exposure is best, but VZIG can prevent or
attenuate varicella if administered within 96 hours
of contact.
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The dose is 125 U/10 kg body weight; 125 U is
the minimum dose. Maximum dose is 625 IU.
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VZIG is administered IM, never IV. The expected
duration of protection is approximately 3 weeks.
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Newborns of mothers who acquired varicella
5 days before to 2 days after delivery
Persons with HIV, AIDS, or other
immunodeficiency disorders
Persons receiving drugs that suppress
immune function (eg, systemic steroids)
Pregnant women
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Complications:
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Secondary bacterial infections
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rapidly spreading cellulitis, septicemia, and
other serious infections may occur.
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The most common infectious organisms
are group A streptococci and
Staphylococcus aureus.
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Signs and symptoms of secondary bacterial
infection can be during the first 3-4 days.
Suspect secondary infection when systemic
manifestations do not improve in 3-4 days,
the fever returns or worsens, or the child's
condition deteriorates after initial
improvement.
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CNS complications
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Acute postinfectious cerebellar ataxia is the most
common CNS complication
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Ataxia has sudden onset that usually occurs 2-3 weeks
after the onset of varicella. The condition may persist for
2 months.
The prognosis for patients with ataxia is good, but a few
children may have residual ataxia, incoordination
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Encephalitis occurs in 1.7 patients per
100,000 cases.
The disease manifests during acute varicella a
few days after rash onset. Lethargy,
drowsiness, and confusion are the usual
presenting symptoms.
seizures, deep coma.
5-20% mortality rate.
Reye syndrome
aseptic meningitis, Guillain-Barré syndrome
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Pneumonia:
Pneumonia occurs primarily among
older children and adults and can have
a fatal outcome.
Respiratory symptoms usually appear 34 days after the rash.
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Herpes zoster:
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A delayed complication of varicella, herpes
zoster infection, occurs months to years after
the primary infection in about 15% of
patients.
The complication is caused by virus persisting
in the sensory ganglions.
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Otitis media:
About 5% of children with varicella
Thrombocytopenia
Hepatitis is a self-limited , Liver involvement is
independent of the severity of skin and systemic
manifestations.
Glomerulonephritis
Hemorrhagic varicella
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Prognosis:
excellent prognoses.
Children with immunocompromised states are
at risk for severe disease and death (eg, the
mortality rate among children with leukemia
is 7%).
Neonatal varicella mortality rates can reach
30%.
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Patient Education:
Bathe the child regularly to reduce
itching and prevent secondary infection.
Scratching can lead to secondary
infection and scarring.
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Keep the fingernails short.
Wearing mittens or socks on the hands at
night can help prevent scratching.
Do not use medications containing
aspirin.
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Advise parents to take children to the
hospital if the following symptoms
occur:
Unusual redness, swelling, or pain
over an area of the rash
 Refusal to drink fluids
 Signs of dehydration
 Confusion, irritability, drowsiness, or
difficulty waking
 Inability to walk or unusual weakness
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severe headache, stiff neck,
and/or back pain
 Frequent vomiting
 Difficulty breathing, chest pain,
wheezing, fast breathing, or
severe cough
 Fever persisting more than 4
days or fever returns after
defervescence
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The Pleomorphic Rash characteristic
of varicella.
Papules, Vesicles, and Pustules exist
concurrently.