Upper respiratory tract infections
affect the airways in the nose, ears, and throat. Viruses, bacteria,
or other microscopic organisms can cause them. In most cases these
infections, including colds, flus, and acute bronchitis, are mild,
temporary, and harmless. In rare cases, they can cause serious
infections in the ears or sinuses or even evolve into pneumonia.
Common
Cold
The common cold is the most common
upper respiratory tract infection. More than 200 viruses can cause
colds, the most common being the rhinovirus, which causes more
infections in humans than any other microorganism. Symptoms of
a common cold (nasal congestion, muscle aches, fatigue, and fever)
are mild. A cold nearly always starts with throat irritation and
stuffiness in the nose. Within hours, full-blown cold symptoms
usually develop, which can include sneezing, mild sore throat,
low-grade fever, minor headaches, muscle aches, and coughing.
Nasal discharge is usually clear and runny the first one to three
days; it then thickens and becomes yellow to greenish. A runny
nose usually lasts two to seven days, although coughing and nasal
discharge can persist for more than two weeks.
Influenza
(Flu)
A virus always causes influenza,
commonly called the flu. The symptoms usually always include headache,
muscle aches, fatigue, and high fever (>101 degrees F.). Influenza
may also cause a cough (which is usually dry but can be severe)
and sometimes a runny nose and sore throat.
Strep
Throat
Sore throat during a cold is very
common and usually mild and in nearly all such cases is caused
by a virus. The symptoms of the more serious so-called strep throat,
which is caused by the group A Streptococcal bacteria, include
a sudden onset of severe sore throat, difficulty in swallowing,
and fever. The patient may also have a headache, stomach pain,
and vomiting. Only about half of patients with strep throat have
such clear-cut symptoms, however. Furthermore, half of people
who have these symptoms do not actually have strep throat. Strep
throat is most likely to occur in late winter and early spring
and is not usually accompanied by a cough or nasal congestion.
Acute Bronchitis
Acute bronchitis is an infection
in the passages that carry air from the throat to the lung, causing
a cough that produces phlegm. In such cases, the airway tubes
have become inflamed and collected mucus. In 95% of cases, acute
bronchitis is caused by a virus and is spread from person to person
through coughing. In some cases other tiny microbes called Mycoplasma
or Chlamydia may be responsible. The cough usually lasts for about
a week to ten days but in about half of patients coughing can
last for up to three weeks and 25% of patients continue to cough
for over month.
Who Gets
Upper Respiratory Infections?
Everyone gets a cold or upper
respiratory infection at some time. On average, Americans develop
two to four colds a year, which totals to about 200 million colds
a year.
Smoke and Environmental
Pollutants
The risk of respiratory infections
is increased by exposure to cigarette smoke, which can injure
airways and damage the cilia (tiny hair-like structures that help
keep the airways clear). Toxic fumes, industrial smoke, and other
air pollutants are also risk factors.
Medical Conditions
People with AIDS and other medical
conditions that damage the immune system are extremely susceptible
to serious infections. Cancers, especially leukemia and Hodgkin's
disease, put patients at risk. Patients who are on corticosteroid
(steroid) treatments, chemotherapy, or other medications that
suppress the immune system are also prone to infection. People
with diabetes are at higher risk for flu. Certain genetic disorders
predispose people with these problems to respiratory infections.
They include sickle-cell disease, cystic fibrosis (which causes
mucus abnormalities), and Kartagener's syndrome (which results
in malfunctioning cilia).
People under Stress
Much evidence suggests that stress
increases one's susceptibility to a cold perhaps by increasing
specific immune factors that cause inflammation in the airways.
In one study, people with high stress levels averaged 2.7 upper
respiratory infections during a six-month period and those reporting
low stress averaged 1.5 infections. In another well-conducted
study, high-stress individuals were 1.7 times more likely to have
a cold than low-stress people were. Stress appears to increase
the risk for a cold regardless of lifestyle or other health habits.
And once a person catches a cold or flu, stress can exacerbate
symptoms.
Excessive Exercise
Although long-term effects of
regular exercise are known to improve health, the immediate effect
of exercise on the immune system is uncertain. In people who already
have colds, exercise has no effect on the illness' severity or
duration of the infection. People should avoid strenuous physical
activity when they have high fevers or widespread viral illnesses,
however. High-intensity or endurance exercises appear to suppress
the immune system while they are being performed. Some highly
trained athletes, for instance, report being susceptible to colds
after strenuous events; very low fat diets appear to support this
negative effect on the immune system. A higher fat-diet may help
redress this imbalance (omega-3 fatty acids, found in fish and
canola oil are preferred). Whether carbohydrate loading provides
much additional value is not clear.
Weather
Although most people get colds
in the winter, this is not due to cold weather but most likely
because people spend more time indoors and are exposed to higher
concentrations of rhinovirus, the cause of colds. Dry winter weather
also dries up nasal passages, making them more susceptible to
viruses.
How Serious
Are Upper Respiratory Tract Infections?
In general, upper respiratory
tract infections are common and not serious. However, an average
of 20,000 Americans die every year from complications of influenza,
and there is some indication that the mortality rates are increasing
in recent years. They are a major cause of hospitalization in
people with chronic medical conditions, especially the elderly
and the very young, and particularly those in low socioeconomic
groups. Such hospitalizations have also been increasing over the
past few decades. For example, almost 1.5 million persons were
hospitalized in 1995 after an average increase of more than 28,000
per year since 1980. The hospitalization rate for persons 65 years
of age or older with pneumonia increased by 50% from 1985 to 1995.
Such rates do not include exacerbations of asthma or chronic obstructive
pulmonary disease, such as emphysema or chronic bronchitis.
Complications of Colds
Colds rarely cause serious complications.
In about 1% of cases, a cold can lead to other complications,
such as sinus or ear infections. It can also aggravate asthma
and, in uncommon situations, increase the risk for lower respiratory
tract infections.
Sinusitis. Between 0.5% and 5%
of people with colds develop sinusitis, an infection in the sinus
cavities (air-filled spaces in the skull). Sinusitis is usually
mild, but if it becomes severe, antibiotics generally eliminate
further problems. In rare cases, however, sinusitis can be serious.
Lower Respiratory Tract Infections.
The common cold poses a risk for bronchitis and pneumonia in people
who may be susceptible to infection. Some experts believe that
the rhinovirus may play a more significant role than the flu in
causing lower respiratory infections in such people.
Aggravation of Asthma. Rhinovirus
infections can acerbate asthma in both children and adults and
has reported to be the most common infectious organism associated
with asthma attacks. Some studies have reported the common cold
being associated with between 33% and 71% of severe asthma episodes.
Complications of Strep
Throat
The use of antibiotics has removed
the threat of most complications from streptococcus infection
in the throat (strep throat). However, untreated strep throat
could lead to abscess in the tonsils, scarlet fever, and may even
cause rheumatic fever. Although very rare in the US, rheumatic
fever still occurs occasionally in children. The condition can
injure the heart and have long-term, serious effects.
Complications of Acute
Bronchitis
Acute bronchitis is nearly always
temporary. Sometimes it can last for weeks to months if the airways
are not healing properly. Pneumonia may be present if coughing
is continuous and hacking, if blood appears in the sputum, and
if the patient has a high fever and signs of severe illness, such
as shortness of breath or extreme weakness and fatigue. Of particular
interest and some concern are the roles of Mycoplasma and Chlamydia,
two of the infectious organisms that cause acute bronchitis. These
agents are being investigated for their roles as possible causes
of asthma. Chlamydia is also being investigated as a trigger for
processes leading to coronary artery disease.
Complications of Influenza
Every year, influenza strikes
millions of people worldwide. Although it is usually not serious
in healthy adults, the flu can cause severe complications, particularly
pneumonia, and, in fact, is responsible for about 20,000 deaths
a year. It is uncommon in healthy adults but can develop about
five days after viral influenza, usually in susceptible individuals,
such as people with weakened immune systems, very young children,
hospitalized patients, and drug abusers who use needles. Influenza
epidemics are most serious when they involve a new strain against
which most people are not immune. Such pandemics are worldwide;
they can infect more than one fourth of the population within
a three-month period.
What
Tests May Be Required To Diagnose Complications Of Upper Respiratory
Infections?
Diagnostic tests or examinations
are usually needed only if a clinician suspects serious complications
of colds and flus; although with new treatments available for
influenza, rapid diagnostic tests may become more widely available.
Ruling out Strep Throat
Most cold-related sore throats
are caused by viruses and require no treatment. They may come
on suddenly but are not severe or long-lasting. When the sore
throat is very painful the clinician will want to rule out or
confirm the presence of group A Streptococcal bacteria, the cause
of strep throat, which can be treated with antibiotics. The clinician
will first look for redness, swelling, and pus-filled patches
on the tonsils and back of the throat and feel the sides of the
neck for swollen lymph nodes. The clinician uses a cotton swab
to take a sample of pus in the throat. A culture taken from the
throat sample is the most effective and least expensive test for
confirming the presence of the Streptococcal bacteria. A faster
test called the rapid strep antigen test uses chemicals to detect
the presence of bacteria, but it is not quite as accurate.
Ruling out Allergic Rhinitis
Symptoms of allergic rhinitis
include nasal obstruction and congestion, similar to the symptoms
of a cold. People with allergies, however, are apt to have thin,
clear, and runny nasal discharge, an itchy nose, eyes, or throat,
and recurrent sneezing. Symptoms that appear only during allergy
season (spring or fall) are called seasonal rhinitis (commonly
known as hay or rose fever). Allergens in the house, such as house
dust mites, molds, and pet dander, can cause year-long allergic
rhinitis, referred to as perennial rhinitis.
Ruling out Sinusitis
The signs and symptoms suggestive
of true acute sinusitis include a return of congestion and discomfort
after initial improvement in a cold (called double sickening);
purulent (pus-filled) nasal secretion; a lack of response to decongestant
or antihistamine; pain in the upper teeth pain on one side of
the head; and on leaning forward, facial pain above or below both
eyes. When the diagnosis is unclear or complications are suspected,
further tests may be required
Ruling out Causes of Persistent
Coughing
Over 30 million people seek medical
help each year for persistent coughing. If coughing continues
for longer than a month, the clinician usually checks for causes
other than acute bronchitis. It should be noted, however, that
acute bronchitis caused by a cold can last for several weeks,
and some clinicians believe that a cough should not be considered
to be chronic until it persists for eight weeks. The best approach
is to use diagnostic methods for the most to least common cause.
After acute bronchitis, the other three most common causes of
persistent coughing in adults are, in order of frequency, asthma,
postnasal drip, and gastroesophageal reflux disorder. Chronic
bronchitis is the fourth most common cause. Some experts suggest
that persistent cough first be treated with antihistamines and
decongestants. If coughing doesn't resolve, asthma therapies should
be added. If coughing still persists the patient should be treated
for gastroesophageal reflux disorder. If such treatments fail,
then more invasive tests are required. A simple lung examination
and medical history can often quickly determine a diagnosis. For
more complicated or uncertain cases, other tests may be required,
including lung function studies and x-rays.
Asthma
Acute bronchitis can easily be
confused with asthma, particularly if the cough is accompanied
by wheezing and occurs mostly at night or during activity. Coughing
from acute bronchitis usually (but not always) clears up within
days to a couple of weeks while that from asthma persists. Asthmatic
symptoms from occupational causes can also cause persistent coughing,
which is usually worse during the work week. Tests called the
methacholine inhalation challenge and pulmonary function studies
may be effective in diagnosing asthma.
Postnasal Drip
Postnasal drip is often a symptom
of allergies, viral infections or sinusitis, but sometimes the
cause cannot be determined.
Gastroesophageal Reflux
Disorders
Gastroesophageal reflux disorder
(GERD), in which acid rises from the stomach into the esophagus,
can cause persistent coughing, which is usually worse when lying
down. A diagnosis of gastroesophageal reflux disease can often
be made if taking antacids relieves symptoms. Coughing is the
only symptom, however, in 75% of cases when GERD is its cause.
In such cases, 24-hour monitoring employing an endoscopy, a test
using a tube inserted down the esophagus, may be required for
a diagnosis of GERD. Some research indicates, however, that taking
a medication called a proton pump inhibitor, usually omeprazole,
for two weeks can help treat and diagnose patients with GERD after
asthma and postnasal drip have been ruled out.
Chronic Bronchitis
Chronic bronchitis also causes
shortness of breath and is often accompanied by infection, mucus
production, and coughing, but it is a long-term and irreversible
condition. A diagnosis of chronic bronchitis is suggested when
a patient experiences coughing with sputum on most days for at
least three months of a year, for a minimum of two years. Lying
down at night worsens the condition.
Pneumonia
A patient should always check
with the clinician right away if a high fever and signs of severe
weakness and debility or when blood appears in the phlegm accompany
the cough. When pneumonia is present, coughing is usually persistent
and hacking. Sometimes it is violent enough to affect the chest
muscles or ribs and produce severe pain. The appearance of thick,
greenish or yellowish sputum (phlegm that the patient coughs up)
indicates a bacterial infection but it is not always helpful in
diagnosing pneumonia or assessing severity. In most cases, a clinician
will take a chest x-ray.
Miscellaneous Causes
Some obvious common causes of
chronic coughing include heavy smoking or the use of drugs known
as ACE inhibitors. Uncommon causes of coughing include lung cancer
and tuberculosis, which are usually easily identified by other
symptoms and by specific diagnostic methods.
Diagnostic Tests for Influenza
Rapid tests are now available
for diagnosing influenza A and B.
What
Are the Treatments for the Common Cold?
Drinking plenty of fluids and
getting lots of rest when needed is still the best bit of advice
to ease the discomforts of the common cold. Chicken soup does
indeed help congestion and achiness, but it appears to be the
hot steam that offers the benefit; tea or any hot beverage may
have the same effect.
Stuffy Nose and Congestion
Nasal Wash. For common colds and
mild allergic rhinitis, a nasal wash can be helpful for removing
mucus from the nose. A saline solution can be purchased at a drug
store or made at home. One study reported that neither a homemade
solution (using one teaspoon of salt and one pinch of baking soda
in a pint of warm water) nor a commercial hypertonic saline nasal
wash had any effect on cold symptoms. Some clinicians, however,
argue for the effectiveness of a traditional nasal wash, used
for centuries, that uses no baking soda and more fluid for each
dose and less salt than the saline washes in the study. The patient
leans over the sink head down, pours some solution into the palm
of the hand, and inhales it through the nose one nostril at a
time. The patient spits the remaining solution out and blows the
nose gently. The solution may also be inserted into the nose using
a large rubber ear syringe, available at a pharmacy. Leaning over
the sink head down, the patient inserts only the tip of the syringe
into one nostril. He or she gently squeezes the bulb several times
to wash the nasal passage and then presses the bulb firmly enough
so that the solution passes into the mouth. The process should
be repeated in the other nostril. A nasal wash should be performed
several times a day.
Nasal Strips. Nasal strips (Breathe
Right) are placed across the lower part of the nose and pull the
nostrils open. These strips may open the nasal passages and ease
congestion due to a cold or hay fever. As of yet, there is no
scientific evidence that they offer such benefits.
Nasal Decongestants. Decongestants
may help dry nasal congestion, but they should not be taken for
more than one or two days. They work by shrinking vessels in the
nose. By reducing blockage, they decrease the risk of developing
sinusitis caused by viruses or bacteria. Many over-the-counter
decongestants are available, either in tablet form or as nasal
or inhaled decongestants that are applied directly into the airways
as sprays, drops, or vapors.
Active ingredients in nasal decongestants
include oxymetazoline (Sinex Long-Lasting, Afrin, Sinarest, Dristan
12-Hour, Neo-Synephrine 12-Hour, Nostrilla, NTZ, Vicks), xylometazoline
(Otrivan), phenylephrine (Neo-Synephrine, Nostril Nasal Decongestant,
Sinex), naphazoline (Naphcon Forte, Privine), and tetrahydrozoline
(Tyzine). Oxymetazoline and xylometazoline are long-acting decongestants;
they are effective in a few minutes and remain so for six to eight
hours.
When using a nasal spray, the
patient should spray each nostril once, wait a minute to allow
absorption into the mucosal tissues, and then spray again. This
procedure is repeated again in four hours with drugs containing
pseudoephedrine and every 12 hours with those containing oxymetazoline.
All forms of nasal decongestants may dry out the affected areas
and damage tissues. Keeping the area moist is very important to
prevent this.
Any sprayers, inhalators, or devices
used to deliver the decongestants become reservoirs for bacteria
over time, so should be discarded when the medication is no longer
needed. If the medicine becomes cloudy or unclear, it, too, should
be discarded. Droppers and inhalators should not be shared with
other people, and they should not be inserted into the nostril.
Nasal decongestants are generally
recommended for no more than one to three days because of the
risk of nasal irritation, rebound effect, and dependency. With
prolonged use, nasal decongestants become ineffective; some people
then increase the frequency of their doses to as often as every
hour. Withdrawal from the drug after three to five days then causes
a rebound effect; that is, symptoms of sinusitis and nasal congestion
return. Short-acting nasal decongestants may have a rebound effect
after only eight hours. Nasal forms work faster than oral decongestants
and have fewer side effects but often require frequent administration.
Inhaled decongestants contain
propylhexedrine or levmetamfetamine, also called desoxyephedrine.
Oral decongestants also come in
many brands and contain pseudoephedrine (eg, Sudafed, Vicks NyQuil
Multi-Symptom Cold/Flu Relief Liquid, and Robitussin PE). Sudafed,
which contains pseudoephedrine, is the only over-the-counter single
ingredient oral decongestant.
The most common side effects of
most decongestants are agitation and nervousness. All nasal and
oral decongestants can cause changes in heart rate and blood pressure,
with oral decongestants having a greater effect. The FDA warns
that anyone with heart disease, high blood pressure, thyroid disease,
diabetes, or prostate enlargement problems that cause urinary
difficulties should not use oral or nasal decongestants without
a doctor's guidance. Inhalers that contain propylhexedrine or
levmetamfetamine do not pose these risks. Oral medications with
pseudoephedrine have less of an effect on blood pressure than
those containing phenylpropanolamine, but both should be avoided
by anyone with high blood pressure. Of some concern is a study
indicating that phenylpropanolamine may even increase the risk
for stroke in certain individuals. Although a very rare occurrence,
some experts advise against anyone taking phenylpropanolamine.
Those at risk are people whose
blood vessels are highly susceptible to contraction, including
those with migraines and Raynaud's phenomenon, in which people
are highly sensitive to cold.
Antihistamines. Histamine is the
chemical released when antibodies overreact to allergens and is
the cause of many symptoms of allergic rhinitis. The antihistamines
relieve itching, sneezing, and nasal discharge. Many prescription
and non-prescription antihistamines are available and include
short-acting and long-acting forms. They are generally categorized
as first- and second-generation and are available in tablet, nasal-inhaler,
eye drop, and syrup form. It should be noted that antihistamines
are not generally recommended to relieve the symptoms of the common
cold. Although one study has indicated that older (so-called first-generation)
antihistamines may reduce cold symptoms, experts postulate that
their benefits for the cold are likely to be due to the drowsiness
they cause. The newer, second-generation, antihistamines do not
have these effects and also appear to have no benefits against
colds. People with bacterial infections in the nasal or sinus
passages should not use antihistamines, even during allergy season;
antihistamines thicken mucus secretions and can actually worsen
bacterial infections.
Combination Cold Remedies. Except
in special circumstances, patients should avoid combination cold
remedies. Some ingredients may produce side effects without even
helping a cold. In some cases, the ingredients conflict (such
as a cough expectorant and a cough suppressant). In other cases,
a patient may wish to increase the dosage to improve one symptom,
which serves to increase other ingredients that do no good and
may even be harmful at higher doses.
Cough Remedies
Patients should not suppress coughs
that produce mucus and phlegm; it is important to expel this substance.
To loosen phlegm, patients should drink plenty of fluids and use
a humidifier or steamer. For thick phlegm, patients may try cough
medications that contain guaifenesin (Robitussin, Scot-Tussin
Expectorant), which loosens mucus. For patients with a dry cough,
a suppressant may be useful, such as one that contains dextromethorphan
(Drixoral Cough, Robitussin Maximum Strength Cough Suppressant).
Medications that contain both a cough suppressant and an expectorant
are not useful and should be avoided. Medicated cough drops that
contain dextromethorphan are not very useful. A patient is just
as likely to find relief from hard candy or lozenges. Those that
contain menthol and mild anesthetics, such as benzocaine, hexylrescorincol,
phenol, and dyclonine (the most potent), may soothe mild sore
throat.
Remedies for Sore Throat
Cough drops, throat sprays, or
gargling warm salt water may help relieve sore throat and reduce
coughing. One health professional suggested that people with sore
throats from postnasal drip might try taking a teaspoon of liquid
antacid. They shouldn't drink anything afterward, since the intention
is to coat the throat and help neutralize the acid in the mucus
that might be causing pain. If these home remedies don't help,
or for more severe discomforts, there are many over-the-counter
drug treatments available.
Medications for Mild Pain
and Fever Reduction
Mild pain relievers, such as aspirin,
ibuprofen (Advil), or acetaminophen (Tylenol) may help reduce
fever and relieve mild sore throat and other aches and pains.
Although many people take such medications for colds, one study
suggested that these drugs may actually neutralize the body's
immune response against the rhinovirus and even increase nasal
symptoms, but the study was very small. Aspirin and aspirin-containing
products are almost never recommended for children or adolescents.
Reye's Syndrome, a very serious condition, has been associated
with aspirin use in children who have flu symptoms or chicken
pox.
Supplements
Zinc. There is evidence on the
importance of zinc for maintenance of the immune system, and adequate
zinc levels are important, especially in patients at high risk
for serious infections, such as those with HIV or children with
sickle-cell disease. In such people, supplements may be helpful.
The use of zinc supplements for otherwise healthy people with
colds, however, is uncertain. Some research indicates that zinc
may help prevent the rhinovirus from attaching to nasal passage
membranes. One analysis of studies on the use of zinc supplements,
however, found no significant effect on colds. In 1999, the FDA
charged the manufacturer of the zinc carbonate lozenges Cold-Eeze
and Kids-Eeze Bubble-Gum with making unsubstantiated claims about
their benefits against colds, allergies, and pneumonia. Of some
interest, however, is Zicam, a nasal gel that contains zinc ions
as the active ingredient. The zinc gel may be more effective than
zinc lozenges or sprays because the zinc resides within the nasal
cavity long enough to interact with the virus. More studies are
underway. It should be noted, however, that no one with an adequate
diet and a healthy immune system should take zinc for prevention.
Some research has suggested that taking zinc for long periods,
even in moderate recommended doses, may actually weaken immunity,
reduce HDL (the so-called good cholesterol), and interfere with
copper metabolism. In any case, zinc does not seem to reduce fever
or soothe muscle aches or scratchy throats. Side effects include
nausea and a bad taste, and the mineral may be toxic in large
doses. More studies are needed.
Vitamins. A number of studies
have found that large doses of vitamin C reduce the duration of
the cold by 5% to 50%, depending on the study. Such high doses,
however, may cause headaches and intestinal and urinary problems,
and even kidney stones. Because ascorbic acid increases iron absorption,
people with certain blood disorders, such as hemochromatosis,
thalassemia, or sideroblastic anemia, should particularly avoid
high doses. Large doses can also interfere with anticoagulant
medications, blood tests used in diabetes, and stool tests for
diagnosing colon cancer. It should further be noted that vitamin
C has limited protective properties. In an examination of 60 studies,
the six largest ones reported no preventive effects of vitamin
C in well-nourished individuals. (It may be useful for prevention
of respiratory infections in people in poor health or under heavy
physical stress, however.)
Echinacea. The herbal remedy echinacea
is now commonly taken to prevent onset of cold or flu and to ease
symptoms. There are three species: Echinacea (E.) purpurea , E.
pallida , and E. augustifolio . In some studies, people who took
extracts of either E. purpurea or E. augustifolio experienced
no protection against colds. Others have found benefits with various
Echinacea forms, such as Echinaforce (an Echinacea purpurea-preparation)
and Echinacea purpurea concentrate (same preparation at 7 times
higher concentration). At this time there are no standards or
quality controls available for echinacea (including what part
of the plant to use) or any other herbal remedies. People with
autoimmune diseases or who are allergic to plants in the daisy
family should not take it. No one should take untested so-called
natural remedies without a clinician's approval. No studies have
confirmed the benefits of these medications and many can cause
toxic side effects in large doses.
What
Are the Treatments for More Severe Upper Respiratory Tract Infections?
General Guidelines Regarding
Antibiotics
In spite of strong warnings by
experts that colds and their symptoms never require antibiotics,
many physicians feel pressured by patients into prescribing antibiotics
for mild upper respiratory tract infections. In people with colds,
even the presence of a persistent cough or greenish, thick mucus
does not indicate the need for antibiotics if there are no other
symptoms of infection. Experts estimate that outside the hospital
only half of the antibiotics prescribed for sore throats, 20%
of prescriptions for bronchitis, and virtually no antibiotics
for colds are necessary. Antibiotics may be required in children
and elderly patients with medical conditions that put them at
high risk for complications of respiratory infections. They are
also used for some cases of sinusitis and ear infections, which
are discussed in other reports. Other possible indications for
antibiotics are described below.
Prescribing antibiotics to people
who do not require antibiotics is raising great concern among
health professionals. Increasingly, physicians are reporting strains
of common bacteria that are no longer eliminated using many standard
antibiotics. As of yet, the average person is not endangered by
this problem. The risk is greatest in hospitals and nursing homes,
but it is still not high. Nevertheless, it is important for patients
with mild upper respiratory tract infections to understand that
although antibiotics may bring a sense of security, they provide
no significant benefit and overuse can contribute to the growing
problem of resistant bacteria.
Treatments for Acute Bronchitis or Persistent Coughing
Bronchodilators. For some patients
with acute bronchitis, inhaled medications called bronchodilators
may be effective. These drugs relax and open the airways and so
may relieve symptoms and reduce the duration of the coughing.
The most common bronchodilator used for acute bronchitis is albuterol
(Proventil, Ventolin).
Antibiotics. Acute bronchitis associated with colds is almost
always caused by viruses and almost never warrants antibiotics.
Exceptions possibly include pertussis (whooping cough) or coughing
that lasts longer than 10 days in children with chronic lung disease
(not asthma). Clinicians may also prescribe antibiotics for persistent
coughing if they suspect that the conditions are caused by the
organisms Mycoplasma or Chlamydia, which usually develop in older
children and young adults. In such cases, antibiotics known as
macrolides (erythromycin, azithromycin, clarithromycin, clindamycin)
are useful for such patients older than five years old. Oral erythromycin
is the first choice for young nonsmoking patients with Mycoplasma
or Chlamydia infection without other medical problems. For smokers
and patients who cannot take erythromycin, clarithromycin and
azithromycin are good alternatives. Some clinicians believe that
antibiotics may prevent bacterial infections from developing in
the lungs of patients with acute bronchitis, although several
studies have reported few or no benefits from antibiotics for
uncomplicated bronchitis in either children or adults. Needless
to say, antibiotics are warranted if the coughing is caused by
bacterial pneumonia.
Treatments for Strep Throat
Sore throats associated with colds
are nearly always caused by viruses and should not be treated
with antibiotics. In general, only throat infections caused by
group A Streptococcal bacteria (strep throat) require these medications.
Penicillin is usually the antibiotic of choice unless the patient
is allergic. Many clinicians will prescribe an antibiotic based
on symptoms alone, although studies indicate that only about half
of adults and far fewer children with even strong signs and symptoms
for strep throat actually have Streptococcal infections. There
is no evidence to prove that early antibiotic therapy offers any
greater protection against acute rheumatic fever or recurring
infections than waiting for the laboratory results. In any case,
the clinician should call the patient if culture results are negative
and have them discard and not take any remaining antibiotics.
Treatments for Influenza
Drugs developed to treat and prevent
influenza target either influenza A, the most serious strain of
the virus, or both influenza A and B. Four drugs have been approved
for the treatment, prevention, or both of influenza: amantadine
(Symmetrel), rimantadine (Flumadine), zanamivir (Relenza), and
oseltamivir (Tamiflu).
M2 Inhibitors. Amantadine and
rimantadine are called M2 inhibitors. Both offer protection against
influenza A, but not B. They may shorten the duration and lessen
the severity of the flu if given within 48 hours of onset of symptoms.
Side effects of amantadine and, to a lesser extent, rimantadine
include nervousness, anxiety, difficulty concentrating, and lightheadedness.
Rarely, amantadine can cause significant mental and behavioral
changes, usually in elderly people already at risk for psychiatric
symptoms. Neither has proven to reduce the risk for complications
including pneumonia and bronchitis.
Neuraminidase Inhibitors. Zanamivir
(Relenza) and oseltamivir (Tamiflu), called neuraminidase inhibitors,
are proving to be effective for treating both A and B strains
of influenza. They both shorten the duration of the flu by one
to three days but need to be taken within two days of onset of
symptoms. Both are approved for treatment in adults patients;
zanamivir is also approved for adolescents and is proving to be
safe and effective in children over six. Zanamivir is administered
as a nasal spray or inhaler. Side effects are minor, although
people with existing asthma and other lung disorders may experience
airway spasms or lung deterioration after taking the drug, and
such people should use this drug with caution. Oseltamivir works
similarly to zanamivir, but comes in capsule form. Side effects
are also minor but patients taking the oral drug may experience
more nausea and vomiting than those on zanamivir. To date, their
effects on patients with serious medical conditions are not known,
nor whether they have any effect on overall survival rates. There
is some early evidence that they may reduce complications of influenza,
although this needs to be confirmed. Neuraminidase Inhibitors
are much more expensive than M2 inhibitors.
Antibiotics. Antibiotics have no benefits against influenza.
How
Can Upper Respiratory Infections Be Prevented?
Healthy Lifestyle
Hygiene. The best way to prevent
pneumonia is to take measures to avoid the organisms that cause
the respiratory infections, including colds and flus. Everyone
should always wash his or her hands before eating and after going
outside. Ordinary soap is sufficient; antibacterial soaps add
little protection, particularly against viruses. In fact, a recent
study suggests that common liquid dish washing soaps are up to
100 times more effective than antibacterial soaps in killing respiratory
syncytial virus (RSV), which is known to cause pneumonia. Nasal
secretions containing RSV can remain infectious for several hours.
Flus and colds are not spread by touching inanimate objects, such
as subway poles or toilet seats; bacteria do not thrive on such
objects and of the organisms that do survive on inanimate objects,
most are harmless.
Daily Habits. Daily diets should
include foods such as fresh, dark-colored fruits and vegetables,
which are rich in antioxidants and other important food chemicals
that help boost the immune system. Supplements of vitamin C and
E may be helpful, but there is no evidence to prove their benefits,
and high amounts of vitamin C may cause diarrhea. Interestingly,
maintaining an active social lifestyle could help prevent colds.
One study found that the more social interaction a person has
the less likely they are to have a cold, possibly because stress
hormones, which suppress the immune system, are reduced.
Vaccines
Viral Influenza Vaccines. The
two major influenza viruses are called A and B. Unfortunately,
influenza A viruses undergo changes (antigenic drift) over time,
so a vaccine that works one year may not work the next. Vaccines
are then redesigned annually to match the current strain. Influenza
B viruses tend to be more stable than influenza A viruses, but
they too vary. The vaccines use inactivated, not live, viruses.
Flu shots are given in the fall, usually between October and December.
An intranasal vaccine (FluMist)
is made from weakened influenza viruses that are engineered to
grow only in cooler temperatures found in the nasal passages,
not in the warmer temperatures of the lungs and lower airways.
The vaccine boosts the specific immune factors in the mucous membranes
of the nose that fight off the actual viral infections.
The vaccines may be slightly less
effective in the elderly, the very young, and patients with certain
chronic diseases than in healthy young adults. Even in people
with a weaker response, however, the vaccine is usually protective
against serious flu complications, particularly pneumonia, although
patients may still experience symptoms in the upper respiratory
tract (the nose and throat). All adults 50 years and older, particularly
those in nursing homes, and anyone at risk for serious complications
from the flu should have an annual vaccination. Those at high
risk include people with heart disease, lung problems, immune
deficiencies, diabetes, kidney disease, or chronic blood disease,
such as sickle cell disease. Certain other younger adults who
should be vaccinated include health care workers and others who
may expose high-risk people to the flu. Current studies suggest
that influenza vaccinations are very effective for people with
HIV. People at risk for complications of influenza and who are
traveling to the tropics at any time or to the Southern Hemisphere
between April and September should consider vaccination. Pregnant
women who are at risk for complications of influenza should be
vaccinated, usually after the first trimester unless they are
in their first trimester during flu season and their risk for
complications of the flu is higher than any theoretical risk to
the baby from the vaccine.
Newer vaccines contain very little
egg protein, but an allergic reaction still may occur in people
with strong allergies to eggs. Almost a third of people who receive
the influenza vaccine develop redness or soreness at the injection
site for one or two days afterward. Other side effects include
mild fatigue and muscle aches and pains; they tend to occur between
six and 12 hours after the vaccination and last up to two days.
It should be noted that these symptoms are not influenza itself
but an immune response to the virus proteins in the vaccine. Anyone
with a fever, however, should not be vaccinated until the ailment
has subsided.
Where
Else Can People With Upper Respiratory Infections Get Help?
American College of Allergy
Asthma & Immunology
85 West Algonquin Road, Suite 550
Arlington Heights, IL 60005
Call: 847-427-1200
Fax: 847-427-1294
On the Internet: http://allergy.mcg.edu
This organization publishes information
sheets on specific allergies and offers a number for referrals
to allergists in local areas. Their web site is excellent.
