Varicella-zoster virus causes chickenpox during primary infection and shingles during reactivation. Chickenpox presents as a rash that spreads across the body while shingles affects sensory nerves causing a unilateral rash. Measles is a highly contagious viral infection that was common in children. It has an incubation period of 7 to 10 days and presents with fever and a rash spreading from head to foot along with other symptoms. Both viruses infect epithelial cells and can cause complications if not treated properly.
3. TOPIC :- VERICELLA-ZOSTER INFECTION
It is a type of viral infection.
Varicella- zoster virus (VZV) causes primary, latent and
recurrent infections.
The primary infection is manifested as vericella (chickenpox)
while Secondary or reactivated disease is known as Herpes
zoster (shingles).
Structurally , VZV is very similar to HSV, with a DNA core,
protein caspid and a lipid envelope.
However some signs and symptoms appear to be unique to
each infection.
5. HISTOPATHOGENESIS:
Virus-infected epithelial cells show homogeneous
nuclei ,representing viral products , with
margination of chromatin along the nuclear
membrane.
Multinucleation of infected cells is also typical.
6. Acantholytic vesicles eventually break down and
ulcerate.
In uncomplicated cases , epithelium regenerates
from ulcer margins with little or no scar.
7. CLINICAL FEATURES:
Uncommon today in developed countries.
Large majority of the population experienced
primary infection during childhood.
Fever, Chills, Malaise, and Headache may
accompany a rash that involves primarily the trunk
and head and neck.
8. Infection is self limiting and lasts several weeks.
Complications including pneumonitis, encephalitis,
and inflammation of other organs , may occur in a
small percentage of cases during pregnancy, fetal
abnormalities may occur.
11. Clinical Features:
Is essentially a condition of the older adult population and of individuals
who have compromised Immune responses.
Incidence of Herpes Zoster infection increases with age.
Sensory nerves of the trunk and head and neck are commonly affected.
Various branches of trigeminal nerve may result in unilateral, Oral, Facial,
or ocular lesion.
Rash quickly becomes vesicular, pustular and then ulcerative usually
occurs in several weeks.
12.
13. Rubeola (Measles) :
It is a highly contagious viral infection.
Produced by a member of Paramyxovirus, genus
Morbillivirus
German measles is caused by , unrelated virus
of the Togavirus family.
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15.
16. Histopathogenesis
Infected epithelial cells, which eventually become necrotic,
overlie an inflamed connective tissue, that contain dilated
vascular channels and a focal inflammatory response.
Lymphocytes are found in a perivascular distribution.
In Lymphoid tissues, large characteristic multinucleated
macrophages known as Warthin Finkeldey giant cells are
seen.
17. Clinical Features
Measles are now uncommon.
Measles was a disease of children.
Often appearing in winter and spring.
Incubation period of 7 to 10 days, prodromal symptoms of
fever, malaise, conjunctivitis and cough develop.
Complication include Encephalitis and Thrombocytopenic
purpura.
Secondary infection may develop Pneumonia.
