Children's Hospital Colorado

The Difference Between COVID-19, Cold, Flu and Other Bugs Affecting Kids

Mother taking temperature of her son

Cough, cough. Sniff, sniff. “I don’t feel good,” your kid says. Uh-oh, you think. Could it be COVID? It’s a normal reaction. Although getting vaccinated, wearing a face covering, social distancing and frequently washing your hands are the best ways to prevent getting sick with COVID-19 and limit the spread, there’s still a possibility that you or your child may become infected.

Children’s Hospital Colorado pediatric infectious disease specialist Samuel Dominguez, MD, PhD, says that although flu and common cold symptoms can be similar to COVID-19 in kids, there are some important differences to know:

  • COVID-19 seems to spread more easily than the influenza virus (the flu) and other respiratory viruses. The delta variant makes it even more contagious.
  • COVID-19 causes more serious illness in some people than the flu.
  • It takes longer before people show symptoms of COVID-19, and people can be contagious for longer. That’s why testing, quarantine and isolation are so important.
  • There’s a flu vaccine that is readily available and easily accessible. Though the Food and Drug Administration has authorized several safe and effective COVID-19 vaccines for emergency use (and given full approval to one), we're still working to vaccinate most of the adult population and waiting on additional data from studies in kids younger than 5.

Even with these differences in mind, it’s challenging for any parent to sort through the symptoms. Seasonal allergies, wildfire season, poor air quality and an off-schedule cold and flu season only increase confusion.

An unseasonal surge

Now well over a year into the pandemic and with the welcome arrival of safe and effective COVID-19 vaccines, mask use has declined and many more people are mingling. This means viruses and bacteria are mingling more, too.

During 2021 we’ve seen an unusual surge in winter viruses and a corresponding increase in kids coming into pediatricians – and children’s hospitals – with illnesses including severe colds, croup and respiratory syncytial virus, or RSV. These viruses spread mostly through respiratory droplets when people cough or sneeze. The virus that causes hand, foot and mouth disease spreads via dirty hands.

“Our usual respiratory viral season that begins in fall started early this year, during the summer, and we’re still in the midst of it,” says Dr. Dominguez. “We’re seeing large volumes of kids with respiratory illness and anticipate this will continue for the next several months.”

It’s more important than ever to keep up the safety precautions that keep us safe. Converging factors including the delta variant, the surge in respiratory viruses and a national shortage of healthcare workers are keeping leaders at Children’s Colorado focused on “flattening the curve” for kids.

With the help of our experts, we created the following symptoms chart for quickly comparing the overlapping symptoms of COVID-19, other respiratory viruses, the flu, allergies and the effects of poor air quality.

Symptoms quick chart

Remember, not everyone experiences the same symptoms. You should use this quick chart as a starting point only. If your child is sick, be sure to talk with their pediatrician and ask about getting tested.

And a note about wording: Though terms like “the common cold,” “the flu,” “colds” and “cold viruses,” are often used interchangeably, remember that there are many viruses that cause respiratory symptoms in children. Even when we aren’t facing a pandemic, the severity of and treatments for these illnesses vary, which is why asking an expert is always recommended.

Signs and symptoms in kids COVID-19 (the new coronavirus) Influenza (the flu) Common respiratory infections (colds) Seasonal allergies (hay fever) Poor air quality (smoke or ozone)
Onset of symptoms Varies; typically gradual Sudden Varies Typically sudden or ongoing Sudden or gradual, but typically sudden
New loss of taste or smell Sometimes Uncommon Uncommon Sometimes Never
Fever Sometimes*; typically high fever Very common; typically high fever Varies Never Never
Tiredness Severely tired Severely tired Varies Sometimes Sometimes
Cough Very common; typically dry cough Very common; typically dry cough Varies Sometimes Common, especially in those with underlying lung disease like asthma
Headache Common Very common Varies Uncommon Sometimes
Loss of appetite Sometimes Common Varies Less common Uncommon
Muscle and body aches Common Very common Common Uncommon Uncommon
Sore throat Common Common Common Sometimes; typically mild Sometimes
Runny nose/nasal congestion Common Common Common Very common Common
Nausea or vomiting Sometimes Sometimes Less common Uncommon Uncommon
Chills Sometimes Very common Less common Never Never
Diarrhea Sometimes Sometimes Varies Never Never
Shortness of breath/breathlessness Sometimes Sometimes Uncommon Uncommon Common, especially in kids with breathing and heart conditions
Wheezing or audible breathing Sometimes Sometimes Sometimes Uncommon Sometimes, especially in kids with breathing problems like asthma

It can be challenging to identify the cause of symptoms, especially in younger kids. We’ve included additional information about each condition below, signs and symptoms to look for and why testing matters.

*Less than half of children who are diagnosed with COVID-19 will have a fever. Even if your child does not have a fever, it is possible that they could have COVID-19.

Why, when and how to get tested

COVID-19 vs. the flu

COVID-19 vs. a common cold

Common colds are normal. In fact, healthy children get about six colds a year. According to the National Institutes of Health, there are more than 200 different viruses, such as rhinoviruses, that can cause symptoms.

Right now, infectious disease specialists are seeing an uptick in seasonal respiratory viruses since social distancing and other restrictions were relaxed, more people began to mingle and school began.

COVID-19 vs. RSV

The respiratory syncytial virus is a common, cold-like infection that hits most kids before they turn 2. Though RSV typically circulates only in the winter months, it’s made an unseasonal comeback during the pandemic and was common even in late summer of 2021.

COVID-19 vs. ear, nose and throat conditions

Some conditions of the ear, nose and throat are often the result of a respiratory illness like a cold or the flu. In the early stages of the COVID-19 pandemic, doctors were diagnosing fewer ear and sinus infections in children than expected due to public health measures like social distancing and school closures that kept common bacteria and viruses at bay.

Now that many of the public health precautions have been lessened or, in some cases, removed altogether, we’re seeing a surge in bacterial and viral infections in kids. This, in turn, is causing an increase in ear, nose and throat conditions like ear infections, sinus infections and strep throat.

“With the comeback of common respiratory illnesses and viruses like RSV, we’ve again seen an increase in as strep throat and ear infections, says Children’s Colorado pediatric otolaryngologist Sarah Gitomer, MD. “We expect complications of ear, nose and throat infections in winter months, but we’re already experiencing this increase this summer. We anticipate this will worsen going into fall and winter, so it’s a good idea for parents to be aware.”

Read FAQs about respiratory infections this season.

Multisystem inflammatory syndrome in children (MIS-C)

COVID-19 is caused by a virus called SARS-CoV-2. When infected with this virus, most children are asymptomatic, meaning they don’t have any symptoms of COVID-19, or they have mild symptoms. In rare cases, though, there are two reasons some children get very sick.

“One is just a really bad COVID-19 infection that occurs during what we call an acute — or sudden — infection,” says Dr. Dominguez. “The other is a new condition called multisystem inflammatory syndrome in children, or MIS-C, which usually occurs 2 to 6 weeks after becoming infected with SARS-CoV-2.”

Cases of COVID-19 continue to ebb and flow. But when COVID-19 case counts increase, experts expect an increase in MIS-C, Dr. Dominguez says. With the 2020 fall and holiday surge in COVID-19 cases, cases of MIS-C also rose dramatically. Although MIS-C is rare, parents should know the symptoms and keep an eye out for them. The best way to prevent MIS-C is to take the same precautions against COVID-19.

The COVID-19 pandemic has been extremely hard on everyone, especially kids and teens. It can be even harder if your child or someone in your family has COVID-19. Now more than ever it’s important to regularly talk with your child and check in with your teen about their physical and mental well-being and help calm their coronavirus anxiety. Carve out time for your own self-care, too. And help your kids make plans to safely see their friends in person with precautions in place.

Keeping you safe during the pandemic

If your child needs medical care like surgery, urgent or emergency care, mental healthcare, vaccinations or a checkup for a chronic condition, it's critical that they get the care they need from pediatric experts.

At Children’s Colorado, we’re here to deliver high-quality care for kids who need it in the safest environment possible. From requiring face coverings to implementing visitation and screening policies, learn about all the ways we’re keeping your family safe when you come for a visit.

This page was updated Nov. 15, 2021. Recommendations can change quickly in a public health emergency. Please follow all health and safety guidelines set by your local authorities. Reference the CDC and CDPHE for updates.


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