What's the difference between cold and flu?

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What's the difference between cold and flu?

Two winter respiratory illnesses may look alike, but pay attention to

tell them apart. By Jordan Lite.

How many times have you dismissed sniffles as " just a cold, " and

carried on with a stuffed nose and sinuses assuming that the symptoms

would eventually run their course, perhaps a bit more quickly with a

few doses of Mom's homemade chicken soup?

Influenza is another story. The common cold eventually fizzles, but

the flu may be deadly. Some 200,000 people in the U.S. are

hospitalized and 36,000 die each year from flu complications — and

that pales in comparison to the flu pandemic of 1918 that claimed

between 20 and 100 million lives. The best defense against it: a

vaccine. Yet barely 30 percent of 4,000 U.S. adults surveyed said

they'd been inoculated this season, despite a record supply of flu

shots, according to a new RAND Corp. survey. (GlaxoKline, which

makes flu vaccine, helped pay for the survey.)

So what is the difference between a cold and the flu – and how can you

be sure which one you have?

We asked Field, director of the allergy and asthma clinic at

NYU Langone Medical Center/Bellevue Hospital in New York. Following is

an edited transcript of our interview with him.

What causes the flu? How is it different from a cold?

The flu is a viral infection caused by the influenza virus, a

respiratory virus. The common cold is also a viral infection caused by

the adenovirus or coronavirus and there are many, many subsets with a

lot of variability. That's why it's said there's no cure for the

common cold [and] there's no real vaccine. The flu is known to be from

influenza and is preventable with vaccination.

Colds tend to produce runny nose, congestion, sore throat. Influenza

is more pronounced in that it infects the lungs, the joints and causes

pneumonia, respiratory failure and even death. It tends to infect the

intestinal tract more in kids, with diarrhea and vomiting. Because of

the relative immaturity of the gut, they may absorb more virus and

that wreaks more havoc on the intestines. Flu causes epidemics and

pandemics with the potential for mortality, whereas the common cold is

a nuisance for us.

How can someone who's feeling ill distinguish between cold and flu, or

an allergy?

Flu typically starts in early November and can go until March. The

peak time is now — November to January. Allergy is typical in spring

or fall, and cold more so in winter.

The body can respond in only so many ways, but there are things you

can use to differentiate. Allergic symptoms are similar to those of a

cold, but [result from] your immune system responding to something

benign. Usually there's no fever, and there's an allergic

manifestation of itch in the back of the throat or the ears. It's

unlikely with allergy to have body aches. With a cold, there's

sometimes a low-grade fever.

You can tell the difference by the length and severity of the illness

and whether you've had a similar experience in the past. Both colds

and flu usually last the same seven to 10 days, but flu can go three

to four weeks; the flu virus may not still be there, but you have

symptoms long after it's left. Allergy can last weeks or months.

Are the treatments for these illnesses different?

For any of these things, if it affects the nose or sinus, just rinsing

with saline that gets the mucus and virus out is a first-line defense.

It's not the most pleasant thing to do, but it works very well. There

are classes of medicines that can help the flu — Tamiflu and Relenza —

antivirals that block viruses' ability to reproduce and shorten the

length and severity of the illness. But they have to be taken within

48 hours or the cat is proverbially out if the bag [because by then]

the virus has done the most of its reproduction. For a cold or flu,

rest and use decongestants and antihistamines, ibuprofen,

acetaminophen, chicken soup and fluids.

Zinc supposedly helps the body's natural defenses work to their

natural capacity and decrease the severity and length of a cold. Cells

need zinc as a catalyst in their protective processes, so if you

supply them with zinc, it helps them work more efficiently. You should

also withhold iron supplements. Viruses use iron as part of their

reproductive cycle, so depriving them of it blocks their dissemination.

The majority of these infections are not bacterial and do not require

[nor will they respond to] antibiotics. My rule of thumb is that a

viral infection should go away in seven to 10 days. If symptoms

persist after that, you'd consider if it's bacteria like Strep or

Haemophilus influenzae. Those bacteria cause illnesses that are longer

lasting.

Is that treatment approach the same for kids?

In general, the same rules apply: Most children will have six to eight

colds a year in their first three years of life, and most are viral.

It's very easy to test for strep and for that you should have a

[positive] culture [before treating with antibiotics].

Are the strategies for avoiding cold and flu different?

Avoidance is very similar: Strict hand washing, not sharing drinking

cups or utensils, and avoiding direct contact with people who are

sneezing. As long as someone has a fever, they have the possibility to

transmit infection. After they've had no fever for 24 hours, they're

not infectious.

The Centers for Disease Control and Prevention (CDC) now recommends

that just about everyone get the flu shot: kids 6 months to 19 years

of age, pregnant women, people 50 and up, and people of any age with

compromised immune systems. Is the shot beneficial to anyone who gets it?

Unless you have a contraindication, there's no reason not to get it.

Contraindications would include egg allergy (because the vaccine is

grown from egg products), any vaccines within a last week or two, and

active illness at the time of your vaccine.

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