3. DEFINITION:
IT IS A ACUTE HIGHLY INFECTIOUS
DISEASE CAUSED BYVARICELLA-
ZOSTER[V-Z].
IT IS THAT MAY BE ACCOMPANIED
BY FEVER AND MALAISE.
Chickenpox is highly contagious and is generally a disease of childhood
which spread by inhalation of infective droplet or contact with lesion after
10-20 days.
This disease is more common in age group of 5-10 years
INTRODUCTION
4. CAUSATIVE AGENT AND FACTORS
1. AGENT FACTOR:
a)Agent- Causative agent of chickenpox varicella zoster virus
is called “human(alpha) herpes virus 3”.
b)Source of infection: The virus occurs in the oropharyngyeal
secretions and lesions of skin and mucosa.
c)Infectivity- 1 to 2 days before the appearance of rash and 4 to 5days
thereafter.
d)Secondary attack rate- The secondary attack rate in household
contacts approaches 90%.
2. HOST FACTORS:
a)Age- Primarily among children under 10 years of age.
b)Immunity- IgG antibodies protect against varicella zoster virus.
5. 3. PREGNANCY-
a) Infants whose mothers has chickenpox during
pregnancy have higher risk of developing herpes
zoster in the first year of life.
b) Infection during pregnancy presents a risk
for the foetus leading to congenital varicella
syndrome
4. ENVIRONMENTAL FACTORS:
a) Chickenpox shows a seasonal trend in temperate
settings and in most tropical settings, with peak
incidence during winter and spring or in
coolest,driest months in the tropics.
b) VZV(Varicella Zoster Virus)is heat liable.
c) Outside host cell, the virus survives in external
environment for only a few hours.
6. INCUBATION PERIOD
Usually 14-16 days,
although extreme as wide as
7-21 days have been
reported.
INFECTIVE PERIOD
1 day before to 5 days
after appearance of rash.
7. TRANSMISSION
Chickenpox is transmitted from
person to person by droplet nuclie.
Most patients are infected by ‘face to face’
contact.
Contact infection undoubtedly plays a
role when an indivisual with herpes zoster
is an index case.
8. PA THOPHYSIOLOGY
PRIMARY INFECTION:
Transmission is most likely by respiratory route followed by
localized replication at an indemnified site.
The occurrence of vieremia in patient with chickenpox
with supported by the diffuse and scattered nature of the
skin lesion.
Vesicles involve the corium and dermis with degenerative
changes charecteristised by ballooning multinucleated giant
cell and eosinophilic intranuclear inculsions.
9. Localized blood vessels of the skin, resulting in necrosis and
epidermal hemorrhage.
Vesicular fluid becomes cloudy with the recruitment of
polymorphonuclear leukocytes degenerated cells and fibrin.
RECURRENT INFECTION:
It is presumed that virus infects the dorsal root ganglia during
chickenpox, where it remains latent until reactivated.
Lung involvement is characterized by interstitial pneumonitis
multinucleated giant cell formation intracellular inculsions and
pulmonary hemorrhage.
10. SIGNS & SYMPTOMS
Impaired appetite
New lesions may erupt for 1-5days
It is prominent on the face scalp, and
trunk but to a lesser extent it commonly
involves the extremites
The crust usually slough in 7-14days
Generally malise , low grade fever &
anorexia for 24 days
Rashes appears
11. C L I N I C A L F E A T U R E S
The clinical features of chickenpox may vary from a mild
illness with only a few scattered lesions to a severe febrile
illness with widespread rash & there are two stages:
A) PRE-ERUPTIVE STAGE: This stage is very brief, lasting about
24hours.
In adults, the prodromal illness is usually more severe and may
last for 2-3days before the rash comes out.
B) ERUPTIVE STAGE: In children the rash is often the first sign.
It comes on the day fever starts.
12. DIAGNOSIS
Prodrome of low grade fever.
Plemorphic eruption of papules , vesicles , and
pustules.
Typical “dew drop on arose petal appearance.
Exposure 14-20days previously.
Fever and malaise just before or with eruption.
Elisa test.
Direct flouresent antibody kits for rapid diagnosis.
13. TREATMENT
ACETAMINOPHEN: Headache, fever, fatigue and muscle aches.
SOOTHING BATHS: Frequent baths are sometimes helpful to relive
itching.
LOTIONS: The most common lotion used for chickenpox is calamine
lotion.
ANTIHISTAMINES: It is used to control severe itching.
Eg- Deiphenydramine(Benadryl) and Hydroxyzine.
PREVENTING SCRACTHING: All children with chickenpox should
have their nails trimmed short.
14. ACYCLOVIR: It is an antiviral drug that may be used
to treat chickenpox.
OTHER ANTIVIRALS: The antiviral medication ,
Valacyclovir(Valtrex) and Famciclovir(famir) used to be effective
for chickenpox.
15. PREVENTION
In MID 1995 a live attenuated vaccine for varicella was approved
and released commercially.
It is recommended fort administer to all children over 12
months of age who don’t have chickenpox.
This vaccine is 85% effective in preventing illness.
Children receiving the vaccine should not take aspirin for atleast 6
months.
Varicella zoster immunoglobin is effective in preventing
chickenpox in exposed suspectible immunosuppressed
individuals.
17. H E A L T H EDUCATION
Isolate the patient because exudate from the lesion
contain the virus and it will cause transmission.
Prevent the patient from scratching and rubbing
the affected area.
Proper handwashing should be done to avoid
Apply calamine lotion into the body
