Does Your Child Have Allergies, RSV or COVID-19?

Editor’s note: This article originally ran September 2, 2021, and was updated October 27, 2022.

Fall has always meant more sniffles, colds and flu, but these days parents have a lot more to worry about. There are still colds and flu, of course, but also COVID-19, which continues to circulate, and RSV, which is spiking much earlier than normal this year.

“Fall time has always been prime time for illness because kids are getting back together after spending the summer apart, and the close quarters at school make it very easy for them to start transmitting all kinds of infections and viruses to each other,” says UNC Health allergist Edwin Kim, MD. “This was less of a problem over the past couple of years with masking and social distancing, but with people much less likely to wear masks this fall, and the fact that the immune systems of many children may be less primed to fight infection without them having the usual exposures during the pandemic, we could be in for a really tough time this fall and winter.”

Public health officials are reporting a spike in RSV cases and hospitalizations in many parts of the country. Respiratory syncytial virus is a common childhood illness that generally causes mild, cold-like symptoms but can be serious, especially for infants. While RSV typically occurs in colder months, current cases of the illness have been severe enough to require many children to be hospitalized.

All of this has Dr. Kim concerned as a physician and a father—but also as an expert in pediatric allergies, because those are going full-throttle too.

Fall allergies can cause symptoms that are similar to symptoms of RSV:

  • Sneezing
  • Wheezing
  • Coughing
  • Runny nose or nasal congestion
  • Itchy, watery eyes

Of course, several of those symptoms are also indicative of a possible COVID-19 infection. It’s a lot to wade through for any parent, which is why talking to your child’s doctor is always a good idea.

In the meantime, here are four ways to tell the difference between allergies, RSV and other infections such as a cold, the flu or COVID-19:

1. Allergies won’t cause a fever.

The symptoms of RSV, fall allergies and COVID-19 can look very similar with one major exception—a fever.

“Allergies, RSV, COVID and other viral infections can cause significant runny nose, congestion, eye irritation and cough as well,” Dr. Kim says. “So, on the surface, they’ll look very, very similar. One very clear difference is going to be fever. Allergies should not cause any type of temperature at all. If parents detect a fever of 100 or higher, that is an infection as opposed to allergies.”

2. A hallmark of allergies is itchiness.

Allergies typically cause very itchy eyes, itchy nose, maybe even itchy skin.

“An infection may be a little itchy or irritating as well, but this will be very minor compared to the significant congestion, cough and other symptoms that they are having,” Dr. Kim says.

In other words, with allergies, one of the most common symptoms is itchiness, while in infections such as RSV, itchiness in the eyes and nose can occur but other symptoms such as congestion and cough are most noticeable. For example, in a child with allergies what will be most noticeable will be how much they are rubbing his or her eyes and nose and sniffling and clearing their throat. With infections, they might rub their nose a little, but it will be the significant congestion and coughing, as well as fever, that will be most noticeable.

3. Symptoms of allergies last longer than symptoms of RSV.

Usually RSV and other viral infections clear up after one to two weeks.

“If it’s allergies, you are probably looking at least a couple of months’ worth of symptoms or at least until the season ends,” Dr. Kim says.

Fall allergy season usually starts in September and lasts until the first hard frost, which can be December or sometimes even later.

4. Allergy medicine won’t help with symptoms of RSV or other viral infections.

If you think your child has allergies and give him or her allergy medicine and it has little effect on his or her symptoms within 12 to 24 hours, your child might have a viral infection.

“An antihistamine that you can get over the counter should do really well for allergies but likely would have very little effect on infection,” Dr. Kim says. “So, if you have a kid who’s got a lot of those symptoms like a really bad runny nose and cough, and Zyrtec and Benadryl aren’t touching it, it may be because it’s not allergies—it’s an infection.”

If your child has cold-like symptoms and you’re not sure what it is, your child’s doctor can help you figure it out. Don’t send your child to school or other social settings until you’re sure it’s “just” allergies.

If your child isn’t feeling well, talk to your pediatrician or find one near you.