A Guide to Respiratory Viruses in Children

Whether it's a flu, cold, RSV, or COVID-19, it's important to keep kids home when they're sick. Here's what to know about treatments, warning signs, and more.

Parent tending to their sick child. Photo: Getty Images

Many kids spent much of the 2020-2021 school year remote, due to the COVID-19 pandemic. This year, though COVID-19 is still a risk, many adults are vaccinated and kids are back in person in most schools. But as anyone who cares for a child knows, when kids are together, they spread germs. That means that kids are coming down with a number of different bugs.

Unfortunately, most symptoms, “mild or severe, from vomiting and diarrhea to congestion or runny nose, can be found in any cold, the flu, and COVID-19,” says Claire Boogaard, MD, a pediatrician at Children’s National Hospital in Washington, D.C.

Because it’s so hard to distinguish one virus from another in a home setting, “what we’re recommending is that anybody with these symptoms be tested for COVID,” says Sean O’Leary, MD, a professor of pediatrics at the University of Colorado School of Medicine and an infectious disease specialist at Children’s Hospital Colorado. Some schools even require it.

While you should never send a kid to school sick with anything contagious, it’s especially important to keep your child home until you know they don’t have COVID-19. Exposure could put unvaccinated people (including high-risk kids) at risk, and potentially require other students to quarantine for 10 days. A kid who is exposed to the coronavirus will need to stay home for a period of time as well. Anyone exposed should get a PCR test three to five days after exposure, says Amna Husain, MD, a pediatrician based in New Jersey and spokesperson for the American Academy of Pediatrics.

In general, “it’s been a remarkable respiratory [virus] season,” O’Leary says. Last winter, with many people hunkered down at home, there was little circulation of respiratory viruses like the flu and RSV (respiratory syncytial virus, which typically spreads in winter and can be dangerous for very young children and for the elderly). But this summer, there was a significant out-of-season RSV spike, which contributed to filling up pediatric ERs, along with infections from the Delta variant of the coronavirus.

COVID-19, Flu, a Cold, or Something Else?

It’s important to reiterate that because COVID-19 shares symptoms with a long list of other illnesses, anyone with symptoms should be tested to rule out COVID-19. But there are some traits of various bugs that you can use to try to distinguish one virus from another.

More on COVID-19

Pre-pandemic, many pediatricians would have said it’s not really important to know which pathogen a kid has, unless they are very sick, Boogaard says. Generally, home treatment for most circulating viruses is the same: rest, hydration, and alleviating fever and discomfort. If it’s flu season and a pediatrician realizes early on that a kid has the flu, they could potentially prescribe the antiviral Tamiflu, which may help people recover faster if given early enough, Husain says.

Here are some of the things you’ll typically see with respiratory viruses spreading right now:

COVID-19: The one symptom that’s far more common with COVID-19 than with other respiratory viruses is the loss of taste and/or smell, O’Leary says. Other viruses can affect these senses, but right now, most pediatricians will consider that symptom a pretty telltale sign of a COVID-19 case—and it may be the only one that shows up in kids that are otherwise asymptomatic. 

Generally, symptomatic COVID-19 cases come on gradually, over a period of a few days, but there may then be a sudden escalation of symptoms. Some other common symptoms include fever and cough. Gastrointestinal symptoms like diarrhea, nausea, and vomiting sometimes occur. Some kids may experience trouble breathing—a sign that should prompt a call to the pediatrician or in serious cases a trip to the ER. Symptoms can last for several weeks.

Respiratory syncytial virus: RSV tends to start mild, but can escalate suddenly. In pediatric cases, the biggest concerns are for kids under 6 months, or those under 2 years of age with lung or heart disease, who can experience serious trouble breathing that requires hospitalization. (In older children, RSV infections usually cause a cold-like illness.) Fevers are common, as are coughs, sore throats, runny noses, and sneezing. Pediatricians can generally identify an RSV cough from down the hall, O’Leary says—and can quickly diagnose the virus with a test if needed.

Influenza: The flu can be severe for children, and it’s important to get flu shots now that flu season has started. According to Boogaard, flu is often characterized by its abrupt onset: Symptoms tend to appear much more quickly than with other respiratory diseases. Sore throats, fevers, fatigue, coughs, headaches, and body aches are all common symptoms, and gastrointestinal symptoms also sometimes occur.

Colds: Colds are caused by many different viruses, including other coronaviruses and rhinoviruses, Boogaard says. Because of this, time of onset and typical symptoms vary, she says. But symptoms typically peak after about three to five days. Most kids are better within seven to 10 days, though a cough may linger for a couple of weeks. 

Allergies: Allergies can cause a number of symptoms seen with respiratory viruses, including runny nose, congestion, sneezing, and watery eyes. But if your child develops a fever, that is not caused by allergies, Boogaard says. And if they are on allergy medication but start to develop new symptoms, that’s another sign they should be checked out.

Treatment and Emergency Signs

In most cases, kids can be treated at home for a respiratory virus, Husain says. Rest is essential, and hydration is important too. Let them drink what they want—warmer fluids like soups may be helpful, she says. Saline drops can help clear nasal passages, which can help with cough or congestion. 

It’s fine to give kids medication to reduce fever, like children’s acetaminophen or ibuprofen, Husain says. But doctors don’t recommend any cough medicines for kids 6 and under, since these can cause changes in heart rate and pose a serious risk. 

It’s always a good idea to get in touch with your pediatrician when your child is sick, Husain says, so they can keep an eye on things and give you some guidance on red flags to look out for. 

Some emergency signs include the inability to get water down or stay hydrated. Young kids should have three to five wet diapers, kids should be able to make tears, and their tongues should not look dry. If kids appear to be having trouble breathing, they should be seen by a pediatrician—or at the hospital if it’s clear they are struggling. Signs of breathing trouble include wheezing or seeing their ribs or chest working hard to get air in. If it’s hard to wake kids up, beyond normal tiredness, or to keep them awake, that lethargy is also an emergency sign, Boogaard says.

If your child does test positive for COVID-19, you’ll want to provide the same supportive care at home. Doing so will be much easier if you are vaccinated, Boogaard says. If you are not, try to find a vaccinated adult who can look after them. As much as you can, it’s good to try to isolate a sick person and to wear masks while interacting with them, she says, though that’s not always possible with younger kids.

Going Back to School or Daycare

Many schools have policies in place that determine when kids can return after testing positive for COVID-19 or being exposed to the virus. Because of these policies, kids may also need a negative COVID test and/or a pediatrician’s note to return after having any symptoms.

For other bugs, you should make sure kids have been fever-free for 24 hours without medication before taking them back to class. If they have been vomiting or having diarrhea, that should also be resolved before they return. 

A cough can last for two weeks after a cold, though it may last longer in kids with allergies or asthma. Kids can generally go back to school with that lingering cough—just get a note from their pediatrician if you need one. 

Getting your child vaccinated against COVID-19 whenever a vaccine is authorized for them will make navigating this confusing time easier, says Boogaard, who is also the medical director of the Covid-19 Vaccine Program at Children’s National Hospital. And if your child is not caught up on their other vaccinations, like those for measles, because of the pandemic, it’s important to do that as soon as possible. “A lot of those diseases are more severe in kids than COVID,” O’Leary says.


Head shot image of CRO Health editor Kevin Loria

Kevin Loria

I'm a science journalist who writes about health for Consumer Reports. I'm interested in finding the ways that people can transform their health for the better and in calling out the systems, companies, and policies that expose patients to unnecessary harm. As a dad, I spend most of my free time trying to keep up with a toddler, but I also enjoy exploring the outdoors whenever possible. Follow me on Twitter (@kevloria).