Bringing sniffles and sneezes and perhaps a sore throat and annoying cough, the common cold catches all of us from time to time.

With kids getting as many as eight colds per year or more, this contagious viral infection of the upper respiratory tract is the most common infectious disease in the United States and the No. 1 reason kids visit the doctor and stay home from school.

Causes

Most colds are caused by rhinoviruses that are in invisible droplets in the air we breathe or on things we touch. More than 100 different rhinoviruses can infiltrate the protective lining of the nose and throat, triggering an immune system reaction that can cause a throat sore and headache, and make it hard to breathe through the nose.

Air that's dry — indoors or out — can lower resistance to infection by the viruses that cause colds. And so can being a smoker or being around someone who's smoking. People who smoke are more likely to catch a cold than people who don't — and their symptoms probably will be worse, last longer, and are more likely to lead to bronchitis or even pneumonia.

But despite some old wives' tales, not wearing a jacket or sweater when it's chilly, sitting or sleeping in a draft, and going outside while your hair's wet do not cause colds.

Signs and Symptoms

The first symptoms of a cold are often a tickle in the throat, a runny or stuffy nose, and sneezing. Kids with colds may also have a sore throat, cough, headache, mild fever, fatigue, muscle aches, and loss of appetite. Nasal discharge may change from watery to thick yellow or green.

Contagiousness

Colds are most contagious during the first 2 to 4 days after symptoms appear, and may be contagious for up to 3 weeks. Your can catch a cold from person-to-person contact or by breathing in virus particles spread through the air by sneezing or coughing. Touching the mouth or nose after touching skin or another surface contaminated with a rhinovirus can also spread a cold.

Prevention

Because so many viruses cause them, there isn't a vaccine that can protect against catching colds. But to help prevent them, kids should:

• try to steer clear of anyone who smokes or who has a cold. Virus particles can travel up to 12 feet through the air when someone with a cold coughs or sneezes, and secondhand smoke can make your child more likely to get sick.
• wash their hands thoroughly and frequently, especially after blowing their noses
• cover their noses and mouths when coughing or sneezing (have them sneeze or cough into a shirtsleeve, though, not their hands — this helps prevent the spread of germs)
• not use the same towels or eating utensils as someone who has a cold. They also shouldn't drink from the same glass, can, or bottle as anyone else — you never know who might be about to come down with a cold and is already spreading the virus.
• not pick up other people's used tissues

Researchers aren't sure whether taking extra zinc or vitamin C can limit how long cold symptoms last or how severe they become, but large doses taken every day can cause negative side effects.

The results of most studies on the value of herbal remedies, such as echinacea, are either negative or inconclusive, and few properly designed scientific studies of these treatments have been done in kids.

Talk to your doctor before you decide to give your child any herbal remedy or more than the recommended daily allowance (RDA) of any vitamin or supplement.

Duration

Cold symptoms usually appear 2 or 3 days after exposure to a source of infection. Most colds clear up within 1 week, but some last for as long as 2 weeks.

Treatment

"Time cures all." That may not always be true, but in the case of the common cold, it's pretty close. Medicine can't cure the common cold, but it can be used to relieve such symptoms as muscle aches, headache, and fever. You can give your child acetaminophen or ibuprofen based on the package recommendations for age or weight.

However, aspirin should never be given to children younger than 12, and all kids and teens under age 19 shouldn't take aspirin during viral illnesses because such use may increase the risk of developing Reye syndrome, a rare but serious condition that can be fatal.

Although you may be tempted to give your child over-the-counter (OTC) decongestants and antihistamines to try to ease the cold symptoms, there's little or no evidence to support that they actually work. In fact, decongestants can cause hallucinations, irritability, and irregular heartbeats, particularly in infants, and shouldn't be used in kids younger than 4 years old without first consulting a doctor. And many experts now believe that there's usually no reason to use these medications in any child younger than 6.

Some ways you can help ease cold discomfort include:

• saltwater drops in the nostrils to relieve nasal congestion (you can buy these — also called saline nose drops — at any pharmacy)
• a cool-mist humidifier to increase air moisture
• petroleum jelly on the skin under the nose to soothe rawness
• hard candy or cough drops to relieve sore throat (for kids older than 3)
• a warm bath or heating pad to soothe aches and pains
• steam from a hot shower to help your child breathe more easily

But what about chicken soup? There's no real proof that eating it can cure a cold, but sick people have been swearing by it for more than 800 years. Why? Chicken soup contains a mucus-thinning amino acid called cysteine, and some research shows that chicken soup helps control congestion-causing white cells, called neutrophils.

The best plan, though, is not to worry about whether to "feed a cold" or "starve a fever." Just make sure your child eats when hungry and drinks plenty of fluids like water or juice to help replace the fluids lost during fever or mucus production. Avoid serving caffeinated beverages, though, which can cause frequent urination (peeing) and, therefore, increase the risk of dehydration.

When to Call the Doctor

Your doctor won't be able to identify the specific virus causing cold symptoms, but can examine your child's throat and ears and take a throat culture to make sure the symptoms aren't from another condition that may need specific treatment. If symptoms get worse instead of better after 3 days or so, the problem could be strep throat, sinusitis, pneumonia, or bronchitis, especially if your son or daughter smokes.

Taking a throat culture is a simple, painless procedure that involves brushing the inside of the throat with a long cotton swab. Examining the germs that stick to the swab will help the doctor determine whether your child has strep throat and needs treatment with antibiotics.

If symptoms last for more than a week, appear at the same time every year, or occur when your child is exposed to pollen, dust, animals, or another substance, an allergy could be to blame. Kids who have trouble breathing or wheeze when they catch a cold could have asthma.

Always call the doctor if you think your child might have more than a cold, your child gets worse instead of better, or if any of these symptoms appear:

• coughing up a lot of mucus
• shortness of breath
• unusual lethargy/tiredness
• inability to keep food or liquids down or poor fluid intake
• increasing headache or facial or throat pain
• severely painful sore throat that interferes with swallowing
• fever of 103°F (39.3°C) or higher, or a fever of 101°F (38.0°C) or higher that lasts for more than a day
• chest or stomach pain
• swollen glands (lymph nodes) in the neck
• earache

Like most virus infections, colds just have to run their course. Getting plenty of rest, avoiding vigorous activity, and drinking lots of fluids — juice, water, and noncaffeinated beverages — all may help your child feel better while on the mend.

Keeping up regular activities like going to school probably won't make a cold any worse. But it will increase the likelihood that the cold will spread to classmates or friends. So you might want to put some daily routines aside until your child is feeling better.

Reviewed by: Steven Dowshen, MD
Date reviewed: February 2013
Originally reviewed by: Iman Sharif, MD