Back to school time is germ time, but how do you know if those sniffles are a cold, flu, allergies or COVID-19?
The Messenger spoke with infectious disease physician and researcher Pritish Tosh, M.D. from the Mayo Clinic for guidance.
How can people tell the difference among these common illnesses?
Dr. Tosh: When people aren't feeling well with some sort of upper respiratory illness, it can be difficult to ascertain whether it’s an allergy, cold, influenza or COVID. And there's some clues that can help distinguish them, but sometimes it's completely indistinguishable, especially if the symptoms are not very severe.
If there is fever involved, it is not an allergy. However, you can have a sneezing, a cough and watery eyes with an allergy.
Okay, so a fever removes allergies from the list.
Right. And more severe infections, the kind that make it really hard to breathe, where you get really high fevers and it knocks you out for days and days — that is really unlikely to be a cold. Now we're in the realm of influenza or COVID.
That's not to say that all influenza viruses will cause severe infection and all cold viruses will cause insignificant infections. But across the board, influenza is just a more pathogenic virus. And it's not just the virus itself, it's your body's response to the virus. [It’s] the amount of inflammation that happens in the lungs as well as the rest of the body that determines how severe the disease is going to be.
When I was a kid, the playground wisdom was green snot means you have a cold and clear snot is allergies. Is that true?
No, the greenness is related to the white blood cells and you can have white blood cells with severe allergies.
In general, bacterial infections are going to cause greener, thicker mucus. But that's not to say you can't get that with a viral infection — especially when we're talking about influenza.
When are antibiotics necessary?
It's rarely necessary. Antibacterials are effective against bacteria and they really have no impact on viral infections. There can be some impact of certain antimicrobials to reduce lung
inflammation, so people may actually feel better, even though the drug is not impacting the virus itself.
But there are lots of other ways to feel better, too. And that includes lots of fluid, lots of rest, and taking over-the-counter pain medications as you need it.
There's a lot more negative impacts of antibiotic use on our normal gut flora. And really, every dose of antibiotic you take, your gut flora takes a hit and doesn't always recover in the way it was before. We're finding so many different things tied to disruptions of the normal gut flora and just taking probiotics or eating yogurt — that's not going to help.
So really the best thing to do is to reduce your unnecessary antibiotic exposure.
So if you don’t need or want to avoid antibiotics, what should you do?
Stay at home, get plenty of rest and plenty of fluids.
But for people who are having severe symptoms or are at risk of complications, they need to contact their healthcare provider as we need to figure out what it is and potentially need to treat it.
What do you think about this year’s flu shot? Is it a good match?
It is always difficult to predict. Looking at the Australian experience from their winter, our summer, it seemed to be well-matched.
They had a lot of H1N1 virus and ended up with a lot of kids actually getting hospitalized. Now, most of us who've been around since 2009, when this virus emerged, have been infected and have some residual immunity, whereas H1N1 has not really been circulating in high numbers in the United States since before COVID. So young kids have largely not seen it. And so I think even if it's well-matched, we may still see more kids getting hospitalized this year if it turns out to be indeed an H1N1 virus they saw largely in Australia.
So really reiterating it's not just older adults, but I really want to see kids vaccinated [with the flu shot] this year as well.
When is it time to take a sick kid to the hospital?
If it's an infant and they're not producing enough wet diapers, really not feeding and not responding.
If it’s an older child and they are not able to keep down foods and fluid and struggling to breathe, you really need to seek medical attention.
And do you advise getting the latest COVID booster?
Yes. Most people focus on the antibodies, and yes they are what keep us from getting infected, but there's another piece of the immunity that's important — that's the cellular immunity, the T-cells, and that keeps us from getting sick.
The more exposure we have to mRNA vaccines, which really trigger the T-cells or natural infection, the broader and deeper our T-cell immunity is. So the vaccines help an otherwise healthy individual who gets a COVID infection to have very minimal symptoms.
People who are at high risk, and that includes older adults and people who are immunocompromised or otherwise high risk, should get vaccinated.
So the best way to identify a COVID infection is with a test, since the symptoms are changing?
Right. Last year there were more COVID hospitalizations and deaths than influenza, but I suspect at some point — and maybe some point soon — that the two viruses will change places and we'll see influenza taking over again as the main driver of wintertime hospitalization and deaths.
*This interview has been edited for clarity and conciseness.