Sneezing, scratchy throat, runny nose-everyone knows the first signs of a cold,
probably the most common illness known. Although the common cold is usually
mild, with symptoms lasting 1 to 2 weeks, it is a leading cause of doctor visits
and missed days from school and work. According to the Centers for Disease
Control and Prevention, 22 million school days are lost annually in the United
States due to the common cold.
In the course of a year, people in the United States suffer 1 billion colds,
according to some estimates.
Children have about 6 to 10 colds a year. One important reason why colds are
so common in children is because they are often in close contact with each other
in daycare centers and schools. In families with children in school, the number
of colds per child can be as high as 12 a year. Adults average about 2 to 4
colds a year, although the range varies widely. Women, especially those aged 20
to 30 years, have more colds than men, possibly because of their closer contact
with children. On average, people older than 60 have fewer than one cold a year.
CAUSES
The
Viruses
More than 200 different viruses are known to cause the symptoms of the common
cold. Some, such as the rhinoviruses, seldom produce serious illnesses. Others,
such as parainfluenza and respiratory syncytial virus, produce mild infections
in adults but can precipitate severe lower respiratory infections in young
children.
Rhinoviruses (from the Greek rhin, meaning “nose”) cause an estimated
30 to 35 percent of all adult colds, and are most active in early fall, spring,
and summer. More than 110 distinct rhinovirus types have been identified. These
agents grow best at temperatures of about 91 degrees Fahrenheit, the temperature
inside the human nose.
Scientists think coronaviruses cause a large percentage of all adult colds.
They bring on colds primarily in the winter and early spring. Of the more than
30 kinds, three or four infect humans. The importance of coronaviruses as a
cause of colds is hard to assess because, unlike rhinoviruses, they are
difficult to grow in the laboratory.
Approximately 10 to 15 percent of adult colds are caused by viruses also
responsible for other, more severe illnesses: adenoviruses, coxsackieviruses,
echoviruses, orthomyxoviruses (including influenza A and B viruses, which cause
flu), paramyxoviruses (including several parainfluenza viruses), respiratory
syncytial virus, and enteroviruses.
The causes of 30 to 50 percent of adult colds, presumed to be viral, remain
unidentified. The same viruses that produce colds in adults appear to cause
colds in children. The relative importance of various viruses in pediatric
colds, however, is unclear because it’s difficult to isolate the precise cause
of symptoms in studies of children with colds.
The weather
There is no evidence that you can get a cold from exposure to cold weather or
from getting chilled or overheated.
Other factors
There is also no evidence that your chances of getting a cold are related to
factors such as exercise, diet, or enlarged tonsils or adenoids. On the other
hand, research suggests that psychological stress and allergic diseases
affecting your nose or throat may have an impact on your chances of getting
infected by cold viruses.
THE COLD SEASON
In the United States, most
colds occur during the fall and winter. Beginning in late August or early
September, the rate of colds increases slowly for a few weeks and remains high
until March or April, when it declines. The seasonal variation may relate to the
opening of schools and to cold weather, which prompt people to spend more time
indoors and increase the chances that viruses will spread to you from someone
else.
Seasonal changes in relative humidity also may affect the prevalence of
colds. The most common cold-causing viruses survive better when humidity is
low-the colder months of the year. Cold weather also may make the inside lining
of your nose drier and more vulnerable to viral infection.
SYMPTOMS
Symptoms of the common cold usually
begin 2 to 3 days after infection and often include
- Mucus buildup in your nose
- Difficulty breathing through your nose
- Swelling of your sinuses
- Sneezing
- Sore throat
- Cough
- Headache
Fever is usually slight but can climb to 102 degrees Fahrenheit in infants
and young children. Cold symptoms can last from 2 to 14 days, but like most
people, you’ll probably recover in a week. If symptoms occur often or last much
longer than 2 weeks, you might have an allergy rather than a cold.
Colds occasionally can lead to bacterial infections of your middle ear or
sinuses, requiring treatment with antibiotics. High fever, significantly swollen
glands, severe sinus pain, and a cough that produces mucus, may indicate a
complication or more serious illness requiring a visit to your healthcare
provider.
TRANSMISSION
You can get infected by cold
viruses by either of these methods.
- Touching your skin or environmental surfaces, such as telephones and stair
rails, that have cold germs on them and then touching your eyes or nose - Inhaling drops of mucus full of cold germs from the air
TREATMENT
There is no cure for the common cold, but you can get relief
from your cold symptoms by
- Resting in bed
- Drinking plenty of fluids
- Gargling with warm salt water or using throat sprays or lozenges for a
scratchy or sore throat - Using petroleum jelly for a raw nose
- Taking aspirin or acetaminophen, Tylenol, for example, for headache or fever
A word of caution: Several studies have linked aspirin use to the
development of Reye’s syndrome in children recovering from flu or chickenpox.
Reye’s syndrome is a rare but serious illness that usually occurs in children
between the ages of 3 and 12 years. It can affect all organs of the body but
most often the brain and liver. While most children who survive an episode of
Reye’s syndrome do not suffer any lasting consequences, the illness can lead to
permanent brain damage or death. The American Academy of Pediatrics recommends
children and teenagers not be given aspirin or medicine containing aspirin when
they have any viral illness such as the common cold.
Over-the-counter cold medicines
Nonprescription cold remedies, including decongestants and cough
suppressants, may relieve some of your cold symptoms but will not prevent or
even shorten the length of your cold. Moreover, because most of these medicines
have some side effects, such as drowsiness, dizziness, insomnia, or upset
stomach, you should take them with care.
Over-the counter-antihistamines
Nonprescription antihistamines may give you some relief from symptoms such as
runny nose and watery eyes which are commonly associated with colds.
Antibiotics
Never take antibiotics to treat a cold because antibiotics do not kill
viruses. You should use these prescription medicines only if you have a rare
bacterial complication, such as sinusitis or ear infections. In addition, you
should not use antibiotics “just in case” because they will not prevent
bacterial infections.
Steam
Although inhaling steam may temporarily relieve symptoms of congestion,
health experts have found that this approach is not an effective treatment.
PREVENTION
There are several ways you can keep yourself from getting a
cold or passing one on to others