 |
| Credit: wikipedia.org (Male with varicella disease) |
Chickenpox, also known as varicella, is a highlycontagious disease caused by the initial infection with varicella zoster virus (VZV). The
disease results in a characteristic skin rash that forms small, itchy blisters, which eventually scab
over. It
usually starts on the chest, back, and face then spreads to the rest of the
body. Other
symptoms may include fever, feeling
tired, and headaches. Symptoms
usually last five to ten days. Complications
may occasionally include pneumonia, inflammation
of the brain, or bacterial infections of the skin among others. The
disease is often more severe in adults than children. Symptoms
begin ten to twenty one days after exposure to the virus.
Chickenpox is an airborne
disease which spreads easily through the coughs and sneezes of an
infected person. It
may be spread from one to two days before the rash appears until all lesions
have crusted over. It
may also spread through contact with the blisters. Those
with shingles may
spread chickenpox to those who are not immune through contact with the
blisters. The
disease can usually be diagnosed based on the presenting symptom; however,
in unusual cases may be confirmed by polymerase chain reaction (PCR) testing
of the blister fluid or scabs. Testing
for antibodies may
be done to determine if a person is or is not immune. People
usually only get the disease once.
The varicella
vaccine has resulted in a decrease in the number of cases and
complications from the disease. It
protects about 70 to 90 percent of people from disease with a greater benefit
for severe disease. Routine
immunization of children is recommended in many countries. Immunization
within three days of exposure may improve outcomes in children. Treatment
of those infected may include calamine
lotion to help with itching, keeping the fingernails short to decrease
injury from scratching, and the use of paracetamol (acetaminophen)
to help with fevers. For
those at increased risk of complications antiviral medication such as aciclovir are
recommended.
Chickenpox occurs in all parts of the world. As
of 2013 140 million cases of chickenpox and herpes
zoster occurred. Before
routine immunization the number of cases occurring each year was similar to the
number of people born. Since
immunization the number of infections in the United States has decreased nearly
90%. In
2013 chickenpox resulted in 7,000 deaths globally – down from 8,900 in 1990. Death
occurs in about 1 per 60,000 cases. Chickenpox
was not separated from smallpox until the late 19th century. In
1888 its connection to shingles was determined. The
first documented use of the term chicken pox was in 1658. Various
explanations have been suggested for the use of "chicken" in the
name, one being the relative mildness of the disease.
Signs and symptoms
A single
blister, typical during the early stages of the rash (
The early (prodromal) symptoms in adolescents and adults are nausea,
loss of appetite, aching muscles, and headache. This is followed by the
characteristic rash or oral sores, malaise, and a
low-grade fever that signal the presence of the disease. Oral manifestations of
the disease (enanthem) not uncommonly may precede the external rash (exanthem).
In children the illness is not usually preceded by prodromal symptoms, and the
first sign is the rash or the spots in the oral cavity. The rash begins as
small red dots on the face, scalp, torso, upper arms and legs; progressing over
10–12 hours to small bumps, blisters and pustules; followed by umbilication and the formation of scabs.
At the blister stage, intense itching is usually present.
Blisters may also occur on the palms, soles, and genital area. Commonly,
visible evidence of the disease develops in the oral cavity and tonsil areas in
the form of small ulcers which can be painful or itchy or both; this enanthem
(internal rash) can precede the exanthem (external rash) by 1 to 3 days or can
be concurrent. These symptoms of chickenpox appear 10 to 21 days after exposure
to a contagious person. Adults may have a more widespread rash and longer
fever, and they are more likely to experience complications, such as
varicella pneumonia.
Because watery nasal discharge containing live virus usually
precedes both exanthem (external rash) and enanthem (oral ulcers) by 1 to 2
days, the infected person actually becomes contagious one to two days before
recognition of the disease. Contagiousness persists until all vesicular lesions
have become dry crusts (scabs), which usually entails four or five days, by
which time nasal shedding of live virus ceases.
The condition usually resolves by itself within a couple of
weeks. The
rash may, however, last for up to one month, although the infectious stage does
not last longer than a week or two.
Chickenpox is rarely fatal, although it is generally more
severe in adult men than in women or children. Non-immune pregnant women and
those with a suppressed immune system are at highest risk of serious complications. Arterial ischemic stroke (AIS)
associated with chickenpox in the previous year accounts for nearly one third
of childhood AIS. The
most common late complication of chickenpox is shingles (herpes
zoster), caused by reactivation of the varicella zoster virus decades
after the initial, often childhood, chickenpox infection. Read more >>
Source: https://en.wikipedia.org/wiki/Chickenpox
No comments:
Post a Comment