Dr. Scott Rens with Sioux Center health encourages community members to get their flu shot every year, but especially this year to mitigate the flu season.

SIOUX CENTER—Influenza, allergies and COVID-19 all share some symptoms, and that can make it difficult to know what’s causing discomfort, especially as influenza season nears.

All three may come on in similar ways, but they’re definitely not the same, said Dr. Scott Rens, a family doctor at Sioux Center Health.

Knowing the signs that the flu, COVID-19 and allergies share, as well as how they differ can be helpful in navigating fall harvest and the flu season the typically stretches November-March, with a peak in January-February.

Influenza, COVID-19 and allergies can all cause:

  • Cough
  • Congestion
  • Runny nose
  • Headaches

Both influenza and COVID-19 can:

  • Cause fever or chills, cough, congestion or runny nose, body aches, headaches, fatigue, and sometimes nausea, vomiting and diarrhea.
  • Be mild or severe, but rarely fatal.
  • Result in pneumonia, which is a deep lung infection.
  • Be spread from person to person through coughing, sneezing, talking or being close to someone who has symptoms, and both can be spread before symptoms appear.

The Centers for Disease Control and Prevention said it’s possible to test positive for flu ­— as well as other respiratory infections — and COVID-19 at the same time.

Rens, however, highlights some additional symptoms of COVID-19 that a person may not experience with influenza or allergies:

  • Difficulty breathing — although allergies may cause shortness of breath.
  • New loss of taste or smell.

“Part of why we’re lucky we’re having COVID now is that we don’t have influenza,” Rens said. “When it first started with COVID last spring, we did and it was harder to understand, especially when COVID can look like influenza or it can look like the common cold or stomach flu. There’s not necessarily a clear progression from one symptom to the next. People even with the same exposure can have different symptoms.”

Rens said his main concern personally is not having much experience with the coronavirus.

“Part of the issue diagnosing is that we don’t have any history with the thing,” he said. “Having been in practice 25 years, I know when somebody has influenza often just by looking at them when they come in the office. COVID is just different. We’re going by what we read in reports but had no hands-on experience at the beginning of this. Unfortunately we’re getting our experience now.”

People with the flu tend to show symptoms within four days of being infected. The time in which people with COVID-19 show symptoms varies; it could be as late as 14 days from infection or as early as two days.

Similarly, people with the flu and COVID-19 can be contagious for about one day before experiencing symptoms. However, those with COVID-19 may remain contagious for up to 10 days after experiencing symptoms, while those with the flu are usually contagious for up to seven days.

Rens said the need to distinguish between the two has not been a challenge recently because the flu season has not fully hit yet.

He urges community members to get their flu shot every year, but especially this year.

“Because there’s so much overlap with symptoms, it’s tough to distinguish between COVID and the flu so if people get their vaccines we can try to mitigate the flu season a bit,” he said. “The vaccine can help keep healthy people healthy through the winter but the bigger public health reason for getting the vaccine that the more people who get the vaccines, the less likely we’ll have significant problems with the vulnerable populations.”

Rens said a new flu shot is needed each season because the virus routinely changes, generally mutating in South East Asia.

“The vaccine put out is the best guess about six months ahead of time for what’s going to hit us this fall,” he said. “In March it’s decided what strain to put in the vaccine. Sometimes it’s right now and we have a mild season. Other times a different strain sneaks in and goes through the community like wildfire. But if the flu shot means a change at mitigating one disease while we have no way of doing that for COVID, I recommend it.”

The best prevention for the spread of either COVID or the flu is to wash hands with soap and water or use alcohol rubs.

“People tend to get flu or COVID from touching things and then putting their hands to their mouth, nose and eyes,” Rens said. “It’s seems simple but getting a vaccine and washing your hands are two very good things that could really help a lot of people stay healthier this winter.”

He recommends the flu shot for people of all ages.

“And just remember, you can’t get the flu from the vaccine,” he said. “People will mount an immune response to it so they might feel flu like, feel achy for a day or so — I do when I get my flu shot — but that doesn't mean you have the flu."