Flu or COVID-19? How to Tell the Difference in Kids

Flu season is ramping up, and your child begins to develop a runny nose or fever.  

“Children are at risk for a wide variety of respiratory illnesses, especially during the winter due to dry air and the fact that we are more often indoors,” says David Walker, M.D., chief of pediatric emergency medicine at Joseph M. Sanzari Children’s Hospital at Hackensack University Medical Center. “It is important for parents to have basic information about the flu and COVID-19 and to know when it’s necessary to get help.”

The flu and COVID-19 are both highly contagious infectious diseases that can affect children of all ages. Since the discovery of COVID-19, we are learning more every day about symptoms, severity and how the disease spreads. Below, Dr. Walker reviews the similarities and differences between the flu and COVID-19 based on what we know so far.

Symptoms of the Flu and COVID-19

Symptoms of the flu typically start one to four days after being infected. Symptoms of COVID-19 usually start five to six days after infection but can happen as early as two days and as late as 14 days. In both cases, you can be contagious before developing symptoms of either illness.

Symptoms of Both Flu and COVID-19

• Fever/chills
• Shortness of breath, difficulty breathing
• Cough
• Extreme tiredness or fatigue
• Muscle pain or body aches
• Headache
• Stuffy, runny nose
• Poor appetite
• Sore throat
• Vomiting and diarrhea (more common in children)

Upper respiratory symptoms, such as runny nose and congestion, are more common with the flu, seasonal allergies and the common cold, than they are with COVID-19. However, some people with COVID-19 do report experiencing those symptoms.

Unique to COVID-19 

• New loss of taste or smell

Is it possible to have the flu and COVID-19 at the same time?

Unfortunately, yes. Given that both the flu and COVID-19 viruses will be circulating during the upcoming flu season, it is crucial that everyone get their annual flu shot to best prevent this scenario.

When to get a COVID or flu test for your child

Because of the large overlap of symptoms between the flu and COVID-19, testing may be necessary to determine the source of your child’s symptoms. Your is the best resource to discuss the need for testing and the available options for testing for the flu and/or COVID-19.

It is also important to consult your child’s pediatrician to help interpret the results. Even if the flu or COVID-19 test is negative, your child’s doctor may still recommend treatment for symptoms or quarantine for suspected COVID-19. Speaking with your child’s pediatrician about test results for COVID-19 is critical, because some tests are more accurate than others, and your child could have a false positive or false negative result. Learn more about COVID-19 tests here.

How long will my child be contagious?

The flu can be contagious for up to seven days after the onset of symptoms. For COVID-19, the risk of being contagious decreases around 10 days after symptoms begin. In each case, you should talk with your child’s pediatrician about when your child would be considered non-contagious.

How are flu and COVID-19 treated?

For both illnesses, the most important treatment is called “supportive treatment.” Is it important to stay hydrated and keep fevers in check. Most cough and cold medications do little to help with symptoms, and as such, are not widely recommended, especially for younger children.

Antiviral medications such as oseltamivir (Tamiflu) may shorten the course of the flu, especially if it is given early in the illness. This is more important for younger children and those with higher risk of severe illness.

There are treatments and interventions that can help patients with serious COVID-19 illness, but there is currently no medicine that kills the virus that causes COVID-19. Most of these treatments are still experimental. Severe cases of either illness may require hospitalization.

Who is at risk for more serious illness?

For the flu, those with highest risk include:

• young children
• pregnant women
• elderly people
• Individuals with chronic medical conditions and/or immunosuppression

People who are highest risk for COVID-19 include:

• Older adults (age 65+)
• Those with underlying medical conditions of the heart, lungs and other major systems
• People who are overweight and obese

While we still have a lot to learn, children are at higher risk of MIS-C, a rare but serious complication of COVID-19.

Where to go for help

Should symptoms of flu or COVID-19 persist or if they are atypical for your child, the first step is to notify your child’s pediatrician. Be sure to also contact your child’s school, if they attend any in-person classes, so the school can notify families of any potential exposure risk.

Next Steps & Resources:

• Meet our Clinical Contributor: David Walker, M.D. 
• CDC: Influenza (flu)
• CDC: COVID-19: Children, Teens and Young Adults

The material provided through HealthU is intended to be used as general information only and should not replace the advice of your physician. Always consult your physician for individual care.