Bronchitis occurs when a respiratory virus or bacteria descends from the nose and throat to the lining of the trachea and the bronchial tubes. The germ clings to the lining and goes into the epithelial or "lining" cells. As the immune system drives away the virus or bacteria, the lining cell is shed and becomes part of the mucous that is coughed up.
In order to get over the bronchitis, the person must not only knock out the germ, but the injured epithelial (lining) cell must be replaced by a new fresh lining cell with a ciliated border (brush border). This process takes time,and that's why it takes awhile for a person to get over a bout of bronchitis. Along the bronchial tree, there can be little fibrin strands left over from the infection and areas without cilia. This can alter the flow of mucous and aggravate the cough receptors.
Coughs are more productive in the morning, as the child wakes up and clears the phlegm that built up overnight. Coughs often vary as people go from outdoors to indoors or vice versa. Sudden bursts of exercise might also bring on the cough. Some infections will bring intermittent bouts of coughing that can go on for weeks. In the days when pertussis was common, children would miss weeks, even months of school because of the severity of the coughing bouts. In nursery schools today, many of the viruses that go around in autumn and winter (parainfluenza, influenza, adenovirus, respiratory synctial virus to name a few) can give a lingering cough. If the child picks up another virus while the previous one is still trailing off, it can seem that the child has a perpetual cold or is "always sick."
As a person experiences different respiratory infections, they build up a library of antibodies that will either block or inhibit the germ the next time it comes around. Grammar school kids can get exposed to just as many viruses as toddlers, but because of the antibodies they've built up over the years, they often have a mild runny nose and cough, instead of a full blown bronchitis.
Antibiotics are usually not used for bronchitis. Most cases are due to respiratory viruses and will resolve spontaneously. Antibiotics have no effect. However, some viral infections, especially influenza, can make the respiratory lining more susceptible to pathogenic bacteria. If a child starts spiking high grade fevers after several days of a respiratory infection, there is a possibility that there is a secondary bacterial infection. In these situations antibiotics are used.
Ways to help fight a cough:
Fruits and juices
Vitamin C has a beneficial effect on the viscosity of the bronchial mucous. It also has an anti-bacterial effect. Rose hip tea (which can be mixed with juice and made as a punch) has vitamin C and also has a bronchial loosening effect. There is also a family of substances called flavinoids, found in certain foods like lemons, grapefruits, grapes, cherries, cranberries and rose hip teas that help "break up" mucous. People tend to like them when they're congested. In China, loquat juice is used for coughs. Licorice tea is used in the mid East. Elderberries are used in northern Europe, as is ivy leaf juice. Health food stores often have products based on these folk remedies.
Warm baths/showers and vaporizers help by making the mucous less sticky. Running the shower or putting damp towels over the radiator can add humidity to a room. A family can use a humidifier, but it's very important to clean them with chlorox so they don't harbor molds. We don't recommend using a humidifier in a bedroom that is dark or in a basement. Constant high humidity can worsen allergies by promoting mold and increasing house mite allergen. If you use a humidifier for a night time cough, make sure it's clean. Most humidifiers can be treated by a dilute solution of chlorox. Another way is to prevent mold is adding 1/4 of a tsp of chlorox per gallon of water in the humidifier. Also, in the morning, open the windows or use a dehumidifier to get some of the excess humidity out of the room.
Avoidance of prolonged cold:
Cold air doesn't cause respiratory infections, but prolonged exposure to cold air and wind can worsen bronchitis. Although the mechanisms haven't been elucidated, prolonged exposure to cold air might decrease the motion of the ciliary border or make the local immune barrier sluggish. Children with bronchitis shouldn't be out for long periods of time in strollers or sitting at the sidelines of parades or soccer games.
Exercise in cold air is OK. It can actually help mobilize secretions and clear secretions. Taking a brisk walk, skiing or ice skating in the cold won't worsen a cough. However, standing still and getting 'a chill' is not good.
People rush out to buy cough medicines in effort to make the cough "go away". They do very little. The immune system does the real job. Fruits are helpful because higher levels of the vitamin C help decrease mucous viscosity.
Guanifesin containing cough remedies such as Mucinex : Guanifesin, which is found in licorice, helps make secretions less tenacious.
Antihistamines like Benadryl can help decrease the post-nasal drip that can aggravate nighttime coughing. Some children can feel a little 'hyper' with Benadryl and others a little droopy. Also, antihistamines can have a drying effect on secretions. It's better to let the natural secretions flow freely during the day and use an anti-histamine only when the child is going to bed.
Most cultures have some sort of 'chest rubs' for infants and children with coughs Many contain eucalyptus or menthol or other "heat" releasing substance like 'mustard plasters". There have not been scientific studies on these substance, except for reported from in China (2005) which showed some benefit of eucalyptus oil on the chests of mice with colds. It is known that there are various receptors in the skin that affect the autonomic nervous system and other neural pathways. Perhaps eucalyptus or menthol chest rubs can help nocturnal cough. It's important however to never let a child have access to and eat them. They can be poisonous if ingested.
Some children with persistent coughs are helped by the anti-inflammatory medications used to treat asthma and allergy. Also, some children require further evaluation such as chest x-ray to rule out a foreign body, or testing for other causes of cough such as gastro-esophageal reflux.
Cough is a very common problem in children, especially among preschoolers as they get exposed to one respiratory virus after another. It's important to bring your child in to be seen if the cough is severe, persistent, or associated with a high fever.