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Colds and the flu (influenza) are common, contagious respiratory illnesses that primarily affect the nose and throat. They cause symptoms such as a sore throat, runny or stuffy nose and coughing. Colds and the flu occur most often between the months of August and May. Most of these infections are mild and resolve without treatment within a week or two.
Contrary to some popular notions, going outside in the cold without a jacket, or with wet hair, does not cause colds or the flu. In order to develop these conditions, a person must first come into contact with a cold or flu virus – usually as a result of contact with germs released after an infected person sneezes or coughs. There are hundreds of different viruses that can cause colds and the flu.
Children are more susceptible than adults to catching a cold or the flu. This may be due to their immature immune systems and the environments in which they may be exposed to germs (e.g., daycare, playgrounds, school). In addition, symptoms of a cold or the flu may develop into more serious conditions, such as pneumonia, ear infections and sinusitis, which can be dangerous for young children.
Diagnosis of a cold or the flu may include a thorough medical history as well as a physical examination. It is not usually necessary to run additional tests to diagnose a cold or the flu, but these tests may help identify other conditions that may be causing the symptoms.
There is no cure for the common cold or the flu. Antibiotics are not effective for viral infections such as colds or the flu. Most treatments aim to reduce or eliminate symptoms. These include over-the-counter and prescription medications – although parents should always consult their child’s pediatrician before providing any medication. All medications (prescription and over-the-counter) have side effects that can be dangerous in children. Other remedies that may help alleviate symptoms of a cold or the flu include saline nose drops, a warm bath, sitting in a steam-filled bathroom, a cool-mist humidifier and chicken soup.
A flu vaccine is available and recommended for infants between the ages of 6 months and 59 months. It may help prevent certain strains of flu each year. Parents should consult with their physician about the best time for their child to begin receiving flu vaccines.
The easiest way to help prevent the spread of both colds and the flu is to practice good hygiene. This includes washing one’s hands after sneezing or coughing, or after caring for or coming into contact with a person with a viral infection. Children’s toys, utensils and other items that may be chewed on or sucked should be washed with soap and water to help prevent the spread of viruses.
The common cold and flu (influenza) are contagious infections caused by viruses that affect the upper respiratory system. Colds and the flu cause a wide variety of symptoms that are usually mild and resolve without treatment within one to two weeks. Children are particularly vulnerable to catching colds or the flu and may experience more severe symptoms than adults.
Viruses that cause colds or the flu enter a person’s body through the mouth or nose. This can occur by inhaling airborne particles after someone with the virus has coughed or sneezed. Virus particles can travel up to 12 feet (3.7 meters) through the air with a sneeze or cough. Infection may also occur by touching a contaminated surface (e.g., skin of an infected person, tissue, doorknob, desktop, laptop), then touching one’s own nose or mouth.
Once inside the body, the virus infiltrates the protective lining of the nose and throat. This causes the immune system to attack the invading virus, resulting in irritation and inflammation of the nose and throat. It is actually the immune system’s reaction to a virus that causes the symptoms of a cold or flu (e.g., a sore throat, stuffy or runny nose). In addition, a runny nose, sneezing, or coughing actually help eliminate the virus from the body and prevent it from spreading throughout the body. Symptoms of a cold or the flu usually appear anywhere from one to three days after the virus has entered the body.
A person may develop an immunity or resistance to specific viruses. Antibodies produced by the immune system in response to a particular virus may prevent reinfection by that same virus. However, because there are hundreds of different viruses that can cause infection and most can change their structure (even slightly) so that the body does not recognize the new viral structure, immunity rarely protects a person from catching another cold or flu virus again. Cold and flu viruses can live on surfaces from a few seconds to two days, depending on the surface and the type of virus.
Colds are the most common infectious disease in the United States, according to the American Academy of Family Physicians (AAFP). Americans experience an estimated 1 billion colds per year. In addition, colds are the primary reason children visit the physician and stay home from school.
The flu affects approximately 10 to 20 percent of people in the United States every year, according to the AAFP. About 200,000 Americans are hospitalized every year for the flu, and 36,000 die annually from the flu and its complications, according to the Centers for Disease Control and Prevention (CDC).
Colds and the flu can sometimes lead to more serious conditions. These include:
When symptoms of nausea, vomiting and diarrhea occur, people sometimes refer to it as the “stomach flu.” This is a misnomer. The flu is a respiratory disease – it does not involve problems of the stomach or intestines. Although flu symptoms can include nausea, vomiting, and diarrhea, these are rarely the only or predominant symptoms of the flu. Patients with these primary symptoms may actually have a stomach or intestinal disorder (e.g., gastroenteritis) rather than the flu.
Colds and the flu (influenza) can be dangerous to infants, since these viral infections may quickly develop into more serious conditions (e.g., pneumonia) in very young children.
For infants age 3 months or younger, parents should contact their child’s pediatrician at the first sign of illness. Signs to look for include:
Infants age 6 months and older may receive flu vaccines, although parents should consult their pediatrician about the best time to begin immunizations for their child.
Because no flu vaccine is approved for babies younger than 6 months of age, parents and other caregivers should take preventive measures to avoid exposing their infant to viral infection. This can be done by getting annual flu shots for all household members and frequent visitors (i.e., grandparents) and ensuring proper hygiene (e.g., frequent handwashing).
Parents should not provide any medications (whether prescription or over-the-counter) to infants without first consulting a pediatrician. Aspirin should not be used in children, due to the risk of Reye syndrome (pronounced “rye”).
With a physician’s approval, parents may help ease some symptoms in their infant. If an infant’s nasal congestion interferes with feedings, for example, parents may wish to clear the infant’s nose with a rubber suction bulb before feedings. This can be done by squeezing the bulb first, then inserting the rubber tip gently into the infant’s nostril and slowly releasing the bulb to draw out the mucus. However, this may not work for infants over the age of 6 months since they may refuse to sit still for this maneuver. In addition, a pediatrician may recommend saline nose drops to soften the nasal phlegm prior to suctioning with the bulb. A cool-mist humidifier or vaporizer may also help alleviate some symptoms of a cold or the flu in infants.
Children have an increased risk of contracting viral infections such as colds and the flu (influenza). Children experience an average of eight to 10 colds per year within the first two years of life, according to the American Academy of Pediatrics. Even after age 2, children may continue to contract colds much more often than adults.
This is mostly due to their exposure to large numbers of other children (e.g., at school, the playground, or daycare facilities) and, thus, an increased potential of coming into contact with a virus. Children cared for at daycare facilities experience significantly higher rates of viral infections than children cared for at home. Viruses are easily spread via school desks, toys, and video games that children may share.
Viral infections in children – especially in those under 5 years old – may be particularly worrisome since young children are more likely to become seriously ill as a result of the flu. Aspirin should not be used in children, especially when a child has a viral infection, due to the risk of the rare Reye syndrome. Over-the-counter cold and flu medications have not been approved for use in children younger than age 2. Studies have found that such medications provide little, if any, symptom relief for this population and, in some cases, can be life-threatening.
The Centers for Disease Control and Prevention (CDC) has recommended that infants between the ages of 6 months and 59 months receive a flu vaccine every year. The vaccine may also be necessary for children living in households where other family members may become seriously ill if exposed to a flu virus (e.g., pregnant women, adults over age 65, anyone with a compromised immune system).
The first time a child receives a flu shot, it will be administered on two separate occasions, one month apart. Thereafter, annual vaccines consist of a single shot in the upper arm. Children over the age of 5 years may be able to receive the vaccine in the form of a nasal spray instead of a shot. Parents should consult with their child’s pediatrician about the best time and form of flu vaccine for their child.
The risk of contracting a cold or flu (influenza) decreases with age. By the time children reach their teenage years, they average between two and four colds per year, which is similar to adults. Adolescents may have developed resistance to viral infections based on their exposure to specific colds or flu viruses through the years. However, teenagers engage in extensive social interaction with people in peer groups and others, so they remain at an increased risk of exposure to cold and flu viruses.
Aspirin should not be used in children (including teenagers), especially when the child has a viral infection, due to the risk of the rare Reye syndrome.
Adolescents are also at an age when they may experiment with certain substances, such as alcohol and cigarettes, which can increase the risk of catching a cold or the flu. These substances may also make cold or flu symptoms more severe and last longer.
Teenagers rarely experience complications from the flu (e.g., pneumonia). However, teens with certain medical conditions (e.g., asthma, diabetes, sickle cell disease) may experience a worsening of these conditions when they have a cold or the flu. A flu vaccine is recommended for this at-risk group of adolescents. Healthy teens may also receive the flu vaccine to help protect them from flu viruses.
In order to catch a cold or the flu (influenza), a person must come into contact with a cold or flu virus. This occurs through contact with an infected person – by inhaling virus particles (made airborne by coughing or sneezing) or touching contaminated surfaces and then touching one’s own mouth or nose.
Contrary to some popular notions, the following do not cause colds or the flu:
Cold and the flu can affect anyone at any age, although children have a greater risk of contracting viral infections than adults. This may be due to the vulnerability of their developing immune systems, as well as the many environments in which viruses can be easily spread (e.g., school, playground, daycare facilities). Children average anywhere from six to 12 viral infections per year, according to the American Academy of Family Physicians (AAFP) – compared to two or three infections per year for adults.
Colds and the flu most often occur during the fall, winter, and spring months. In North America, colds generally appear between August and May (with peaks from August to October and from April to May). Most flu infections appear between November and April (peaking in December through March).
More than 200 viruses can cause colds. Rhinoviruses are the most common cause of colds and there are more than 100 different types of rhinoviruses. However, rhinoviruses do not usually cause serious illness. Other viruses responsible for the common cold include the coronavirus, respiratory syncytial virus, parainfluenza virus, and adenovirus.
The viruses that cause the flu are classified into three types (A, B, and C). Each type may contain a variety of strains. Type A and B flu viruses are the most common, with Type A producing more severe flu symptoms than Type B. Type C flu viruses are rare and produce mild flu symptoms.
Symptoms typically occur between one and three days after being infected with a cold or flu (influenza) virus. On average, symptoms last up to one week, although sometimes they may last two weeks.
Symptoms of a cold and the flu may be similar. The primary difference is that cold symptoms are generally mild and come on gradually, whereas flu symptoms are usually more severe, begin suddenly and last longer than a cold.
Common signs and symptoms of colds and the flu include:
A cold usually begins with throat irritation. Nasal problems, such as a stuffy or runny nose, usually become the dominant symptom after the second or third day of the cold. Coughing is common in children with a cold. Fever is not common with a cold.
With the flu, symptoms usually begin with muscle aches for the first few days, then a stuffy nose and/or sore throat may occur, which may linger. Fever, fatigue, muscle aches, and a dry cough are more common with the flu than with colds. Additional symptoms that occur with the flu, but not a cold, include dizziness, nausea or vomiting, abdominal pain, and diarrhea.
For signs of a cold or the flu specific to infants, see Infant issues for cold & flu.
Parents should seek immediate medical attention for their child if symptoms are severe or persist, or if any of the following occur:
Diagnosing a cold or the flu (influenza) usually begins with a physician performing a thorough medical history that includes a description of symptoms, as well as their duration and severity. A physical examination is often necessary. For example, the presence of nasal secretions can be obvious upon examination and may indicate the presence of a viral infection. Examination of the ears, nose or throat may indicate the presence of a cold or the flu – or may indicate the presence of another condition responsible for the symptoms. In the latter case, additional tests may be necessary to rule out other conditions (e.g., strep throat, asthma, allergies).
Additional tests that can rule out other conditions may include a throat culture, in which the physician uses a long cotton swab to collect a tiny tissue sample from inside the throat. A nasal smear (analysis of nasal excretions under a microscope) or blood tests may also be used. Examination of the ears during the physical examination can help identify an ear infection (otitis media). Tests may be used to identify complications of a cold or the flu, such as sinusitis and pneumonia.
Consulting a physician may not be necessary for mild cases of cold or the flu.
There is no cure for the common cold or flu (influenza). Most treatment remedies focus on reducing or eliminating symptoms.
There is some controversy surrounding the treatment of cold or flu symptoms in children. Symptom relief is based on the assumption that medications that work to alleviate symptoms in adults will have similar effects in children. However, this has not been validated since young children are unable to adequately assist in measuring the effectiveness of medications in clinical studies.
When using medications to treat children, parents must be careful to administer the proper dosage (based on age and size) and proper type of medication for the symptoms that are present. In addition, all medications (prescription and over-the-counter) have side effects that can be dangerous for young children. Parents should consult with their child’s pediatrician to weigh the possible benefits of certain medications against potential side effects. Prolonged use of medications should be avoided and medications should only be administered to a child under the close supervision of a parent or guardian.
In addition, the Food and Drug Administration (FDA) has only approved the use of over-the-counter cold and flu medications in children older than 2 years old. In children younger than age 2, studies have concluded that such medications are not effective in relieving cold or flu symptoms and, in some cases, can be unsafe and even life-threatening for this population.
Antibiotics are not effective against viral infections (e.g., colds, the flu). Yet, every year, millions of people visit the physician for diagnosis or treatment of the common cold. Some of these visits result in prescriptions for antibiotics that do not relieve cold or flu symptoms.
The following medications may provide relief from cold and flu symptoms. However, parents should consult with a physician before treating their child with any of the following:
Expectorants (drugs that thin mucus for ease in coughing it up) are not an effective anti-cough remedy. Antitussives (drugs designed to reduce coughing) are not necessarily effective. Some studies have indicated that a placebo (an inactive material, such as a sugar pill, usually used for research purposes) actually worked better than certain over-the-counter medications designed to reduce coughing. Antitussives should never be used if a child is coughing up mucus.
In the case of the flu, a physician may prescribe antiviral drugs to reduce or eliminate symptoms in patients with a high risk of complications (e.g., infants ages 12 months to 23 months). These must be administered within 48 hours of symptom appearance, and may only work against a certain type of flu. Some may be administered as a preventive remedy as well as a treatment.
Other remedies that may ease the symptoms of a cold include:
Strengthening the body’s immune system can help lessen symptoms when a person is exposed to a virus. This includes getting plenty of rest, eating a balanced diet, and getting adequate exercise.
Some home remedies have focused on the theory of “feed a cold, starve a fever.” Parents are advised to allow children to eat when hungry, regardless of whether the infection is due to a cold or flu virus.
There is no way to prevent a cold once exposed to the virus. Some strains of flu (influenza) may be prevented via vaccines and certain medications. People with a cold or flu are encouraged to stay home, rest and avoid passing the infection to others.
One of the easiest ways to prevent transmission of a cold or flu virus is by practicing good hygiene. This includes washing one’s hands after coughing or sneezing, or after coming into contact with a person with a viral infection. It is also important to cover the nose and mouth when sneezing or coughing. The spread of a virus can also be prevented by not sharing items such as towels, eating utensils, bottles, or beverage containers with others. Tissues should be promptly disposed of after use, and hands should be washed after handling used tissues.
It may be difficult to completely avoid contact with infected persons. Some people with viral infections may be contagious before any signs of illness appear – although people are most contagious during the first two to four days after symptoms appear, according to the American Academy of Family Physicians (AAFP). Some people may continue to be contagious for up to three weeks.
Controversy surrounds some popular over-the-counter medications believed to help prevent viral infection. Parents should consult their child’s pediatrician before providing any herbal remedies or exceeding the recommended daily allowance of any vitamin or supplement. These controversial preventive methods include:
Because fewer varieties of flu viruses exist than cold viruses, a vaccine is available for the flu. Every year, a flu vaccine is developed to prevent three specific strains of flu expected to occur that year. The vaccine is usually given as a shot in the upper arm. This exposes patients to dead flu viruses, helping the body to develop an immunity or resistance to those particular viruses. It may also help those who contract different strains of the flu to have less severe symptoms. Side effects of the flu shot include soreness where the shot was provided, muscle aches, and fever.
The vaccine is also available in nasal spray form, sometimes referred to as LAIV (live attenuated influenza vaccine). This is because it contains live but weakened flu viruses. Side effects of the nasal spray vaccine include a runny nose, headache, cough and sore throat.
Flu vaccines are considered 70 to 90 percent effective in preventing the flu caused by the specific strains contained in the vaccine in healthy people under the age of 65 years, according to the AAFP. Protection lasts for one year, since viruses are constantly changing and new strains must be identified for inclusion in the vaccine.
It is not possible to contract the flu from the vaccine. Flu vaccines are usually provided in the fall, although they may be obtained any time during the flu season (November through April). It can take one to two weeks for the body to build up immunity to the flu viruses contained in the vaccine. Parents should check with their child’s pediatrician before getting a vaccine for their child.
Flu vaccines are recommended for the following groups who are at risk of complications as a result of the flu:
Anyone with the following conditions should not get a flu vaccine without first consulting with a physician:
If flu vaccines are in short supply (usually the result of distribution delays rather than an actual shortage), the CDC may recommend that certain high-risk populations get the shot first.
Antiviral medications may also be used to prevent certain types of flu. Generally, these are used in conjunction with a flu vaccine, especially among high-risk populations.