How Colds are Spread Depending on the virus type, any or all of the following routes of transmission may be common:Touching infectious respiratory secretions on skin and on environmental surfaces and then touching the eyes or nose.Inhaling relatively large particles of respiratory secretions transported briefly in the air.
Inhaling droplet nuclei, which are smaller infectious particles suspended in the air for long periods of time
Handwashing is the simplest and most effective way to keep from getting rhinovirus colds. Not touching the nose or eyes is another. Individuals with colds should always sneeze or cough into a facial tissue, and promptly throw it away. If possible, one should avoid close, prolonged exposure to persons who have colds. Because rhinoviruses can survive up to three hours outside the nasal passages on inanimate objects and skin, cleaning environmental surfaces with a virus-killing disinfectant might help prevent spread of infection.A cold vaccine? The development of a vaccine that could prevent the common cold has reached an impasse because of the discovery of many different cold viruses. Each virus carries its own specific antigens, substances that induce the formation of specific protective proteins (antibodies) produced by the body. Until ways are found to combine many viral antigens in one vaccine, or take advantage of the antigenic cross-relationships that exist, prospects for a vaccine are dim. Evidence that changes occur in common-cold virus antigens further complicate development of a vaccine. Such changes occur in some influenza virus antigens and make it necessary to alter the influenza vaccine each year Pollen AllergyEach spring, summer, and fall, tiny particles are released from trees, weeds, and grasses. These particles, known as pollen, hitch rides on currents of air. Although their mission is to fertilize parts of other plants, many never reach their targets. Instead, they enter human noses and throats, triggering a type of seasonal allergic rhinitis called pollen allergy, which many people know as hay fever or rose fever (depending on the season in which the symptoms occur). Of all the things that can cause an allergy, pollen is one of the most widespread. Many of the foods, drugs, or animals that cause allergies can be avoided to a great extent; even insects and household dust are escapeble. Short of staying indoors when the pollen count is high–and even that may not help–there is no easy way to evade windborne pollen. People with pollen allergies often develop sensitivities to other troublemakers that are present all year, such as dust mites. For these allergy sufferers, the “sneezin’ season” has no limit. Year-round airborne allergens cause perennial allergic rhinitis, as distinguished from seasonal allergic rhinitis.What is pollen?Plants produce microscopic round or oval pollen grains to reproduce. In some species, the plant uses the pollen from its own flowers to fertilize itself. Other types must be cross-pollinated; that is, in order for fertilization to take place and seeds to form, pollen must be transferred from the flower of one plant to that of another plant of the same species. Insects do this job for certain flowering plants, while other plants rely on wind transport. The types of pollen that most commonly cause allergic reactions are produced by the plain-looking plants (trees, grasses, and weeds) that do not have showy flowers. These plants manufacture small, light, dry pollen granules that are custom-made for wind transport. Samples of ragweed pollen have been collected 400 miles out at sea and 2 miles high in the air. Because airborne pollen is carried for long distances, it does little good to rid an area of an offending plant–the pollen can drift in from many miles away. In addition, most allergenic pollen comes from plants that produce it in huge quantities. A single ragweed plant can generate a million grains of pollen a day.The chemical makeup of pollen is the basic factor that determines whether it is likely to cause hay fever. For example, pine tree pollen is produced in large amounts by a common tree, which would make it a good candidate for causing allergy. The chemical composition of pine pollen, however, appears to make it less allergenic than other types. Because pine pollen is heavy, it tends to fall straight down and does not scatter. Therefore, it rarely reaches human noses. Among North American plants, weeds are the most prolific producers of allergenic pollen. Ragweed is the major culprit, but others of importance are sagebrush, redroot pigweed, lamb’s quarters, Russian thistle (tumbleweed), and English plantain.Grasses and trees, too, are important sources of allergenic pollens. Although more than 1,000 species of grass grow in North America, only a few produce highly allergenic pollen. These include timothy grass, Kentucky bluegrass, Johnson grass, Bermuda grass, redtop grass, orchard grass, and sweet vernal grass. Trees that produce allergenic pollen include oak, ash, elm, hickory, pecan, box elder, and mountain cedar.It is common to hear people say that they are allergic to colorful or scented flowers like roses. In fact, only florists, gardeners, and others who have prolonged, close contact with flowers are likely to become sensitized to pollen from these plants. Most people have little contact with the large, heavy, waxy pollen grains of many flowering plants because this type of pollen is not carried by wind but by insects such as butterflies and bees. Symptoms of Allergies to Airborne SubstancesThe signs and symptoms are familiar to many: Sneezing often accompanied by a runny or clogged nose Coughing and postnasal drip Itching eyes, nose, and throat Allergic shiners (dark circles under the eyes caused by increased blood flow near the sinuses) The “allergic salute” (in a child, persistent upward rubbing of the nose that causes a crease mark on the nose) Watering eyes Conjunctivitis (an inflammation of the membrane that lines the eyelids, causing red-rimmed, swollen eyes, and crusting of the eyelids). In people who are not allergic, the mucus in the nasal passages simply moves foreign particles to the throat, where they are swallowed or coughed out. But something different happens to a person who is sensitive to airborne allergens.As soon as the allergen lands on the mucous membranes lining the inside of the nose, a chain reaction occurs that leads the mast cells in these tissues to release histamine and other chemicals. These powerful chemicals contract certain cells that line some small blood vessels in the nose. This allows fluids to escape, which causes the nasal passages to swell, resulting in nasal congestion.Histamine also can cause sneezing, itching, irritation, and excess mucus production, which can result in allergic rhinitis (runny nose). Other chemicals made and released by mast cells, including cytokines and leukotrienes, also contribute to allergic symptoms. When you get your picture taken, everyone says, “Say cheese! Smile!” So you do – you open your mouth and show your teeth. When you see the picture, you see a happy person looking back at you. The healthier those teeth are, the happier you look. Why is that?It’s because your teeth are important in many ways. If you take care of them, they’ll help take care of you. Strong, healthy teeth help you chew the right foods to help you grow. They help you speak clearly. And yes, they help you look your best.
Why Healthy Teeth Are ImportantHow does taking care of your teeth help with all those things? Taking care of your teeth helps prevent plaque which is a clear film that sticks to your teeth. The film itself may not sound so bad, but it’s very sticky, and it acts like a magnet for bacteria and sugar.Just like ants at a picnic, the bacteria go crazy breaking the sugar down into acids. These acids eat away at the tooth enamel, and this can cause cavities. Plaque also causes gingivitis , which is gum disease (this can make your gums red and sore). Your gums are those soft pink tissues in your mouth that hold your teeth in place. Before long, the cavities and gums can become very sore, eating may be more difficult, and you might not feel like smiling so much. Before Toothpaste Was Invented We’re lucky that we know so much now about taking care of our teeth. Long ago, people’s teeth would hurt and rot. To get rid of a toothache, they had their teeth pulled out.Finally people learned that cleaning their teeth was important, but they didn’t have toothpaste right away. While you’re swishing the minty paste around your mouth, think about what people used long ago to clean teeth:ground-up chalk or charcoallemon juiceashes (you know, the stuff that’s left over after a fire)tobacco and honey mixed togetherYuck!Today there are many toothpaste choices. Look for one with fluoride, which makes your teeth strong and fights cavities. You don’t need a lot of toothpaste, though; just squeeze out a bit the size of a pea. It’s not a good idea to swallow the toothpaste, either, so be sure to rinse and spit.It was only about 100 years ago that someone finally created a minty cream to clean teeth. Not long after that, the toothpaste tube was invented, so people could squeeze the paste right onto the toothbrush! It was during World War II that brushing became popular. The U.S. Army gave brushes and toothpaste to the soldiers, and they learned to brush twice a day. How You Can Keep Your Teeth Healthy Brush at least twice a day, after breakfast and before bed. If you can, brush after lunch or after sweet snacks. Brushing properly breaks down plaque. Be sure to brush not just the front of your teeth, but the sides and back of them, too. Brush away from your gums. This helps to keep your gums healthy, too.And take your time. Spend at least 3 minutes each time you brush. If you have trouble keeping track of the time, use an egg timer or play a recording of a song you like to help pass the time.Be sure that your toothbrush has soft bristles (the package the brush comes in will tell you if they’re soft) and that you get a new toothbrush every 3 months.
Floss your teeth, too. It feels weird the first few times you do it, but pretty soon you’ll be a pro. Slip the dental floss in between each tooth and up along the gum line. The floss gets rid of the food that’s hidden where your toothbrush can’t get it. It’s also important to visit the dentist twice a year. Besides checking for signs of cavities or gum disease, the dentist will help keep your teeth extra clean, and he or she can help you learn the best way to brush and floss. It’s not just brushing and flossing that keep your teeth healthy – you need to be careful about what you eat and drink. Remember, the plaque on your teeth is just waiting for that sugar to arrive. Eat lots of fruits and vegetables and drink milk instead of soda. And don’t forget to smile! ConstipationIf you think that you’re having a problem with constipation, tell your parents. They can help you try some very simple ways of getting your bowels back on a regular schedule. Most of the time this means changing the kinds of foods you eat. You may need to eat fewer fatty and greasy foods (like hamburgers and fries) and fewer sugary foods (like candy bars and ice cream). You may need more foods rich in fiber (like fruits, vegetables, and whole grains). Drinking more water each day also helps.Exercise is one of the best ways to keep your digestive system moving, so you may want to switch some TV time for a bike ride or a game of soccer. You might also try getting up a little earlier in the morning to give yourself a few extra minutes to use the bathroom before going to school. And when you’re in school, if you feel the urge to use the bathroom, don’t wait. Waiting for a better time to go only makes constipation worse. And no matter what the TV commercials say, don’t use laxatives unless your parents and your doctor say that it’s OK. Laxatives can actually cause constipation if they’re not used properly.
Diarrhea
Diarrhea means you have to move your bowels frequently, and your bowel movements are loose, mushy, and watery. Sometimes this happens if you change the kinds of foods you eat or if you are taking some types of medicine. Sometimes diarrhea happens when you don’t wash your hands thoroughly after going to the bathroom and before you eat. (Washing your hands is an important part of preventing diarrhea.)
Other times diarrhea is caused by an infection in the intestines or some other part of the body. Sometimes diarrhea is the only symptom of an infection, but some infections can also cause you to have other symptoms, like fever, nausea, vomiting, and feeling “sick.” If this happens, your parents can ask your doctor about medicine or an office visit. Together with your doctor, they can work out a plan to give you foods that are easy to digest while you’re getting better.There may be times when being worried or upset gives you either diarrhea or constipation. Or, you may find that your digestive system seems to be switching back and forth from one problem to the other (constipation-diarrhea-constipation-diarrhea). If this happens, tell your parents. You may have a sensitive bowel that goes into spasms easily. Doctors call this problem irritable bowel syndrome, or IBS |