fbpx Skip nav to main content.
Home > Dr. Megan’s Blog > Infections & Prednisone Side Effects

Infections & Prednisone Side Effects

Infections & Prednisone Side Effects

Infections & Prednisone Side Effects

It’s the time of the year again, Prednisone Warriors! You might be wondering what you should do if you’re around somebody sneezing, coughing, and exposing you to all sorts of germs. Aren’t you more likely to get sick because of Prednisone? Is it easy to determine if you have Infections or just Prednisone Side Effects?

Find out more about what you should and should not worry about by reading this article or by watching the video below.

Watch now!

First of all, I wanted to share with you what you are most likely to run into with Infections and Prednisone Side Effects. So, prednisone as we all know is an immunosuppressant. I took prednisone to decrease my immune system‘s attack on my platelets, my blood cells. And one of the things that it also did, was it changed the number of white blood cells. It shifted the way the white blood cells showed up when they would test my blood. I would have a really high total white blood cell count. But it wasn’t because I had an infection. So, it looked like I had an infection all the time.

If you just went by that one number. If you weren’t a really highly trained doctor, you wouldn’t know that you have to look at all of the other little counts of the white blood cells to know whether it was an infection or not.

Infections vs. Prednisone Side Effects

And so, that is the reason why it’s so hard to tell if you’re having an infection while on prednisone. Because prednisone interferes with your normal signs and symptoms of an infection.

Prednisone Messes Up Neutrophil Count

It can make your neutrophils go crazy, either too high or too low. It can make your body release immature neutrophils, like little baby ones that were just growing, and have them stop adhering to the sides of your blood vessels and go out. Basically, it’s like a girl who’s suddenly out on society before she’s 14. You know, she shouldn’t be getting ready to be married if she’s 13. But that’s what these neutrophils are doing. They are saying, “I’m ready to do my job.” But they’re not, they’re little immature baby things.

And so, your immune system looks different when they test your blood levels. And it acts differently. So, some of the cells are completely wiped off and some of them are really high. And it just makes it trickier to tell, are you having an infection or not? And for people who have cancer or are taking other immunosuppressants, it’s even harder to tell. So, you need to be really careful. In the end, I’ll tell you what we need to look for.

Type of Infections

Listed below are the list of what Prednisone is associated with, as far as which type of infections.


So, first of all, tuberculosis. If you don’t know what that is, they often call it TB. It’s a lung infection. And it can be fatal if it’s not treated. And it takes a long time to kill you if you don’t get treatment. So, it’s often just this hacking cough that never goes away. And most people in America will never ever get TB, because you usually have a strong enough immune system.


It’s when your entire body is infected, including your blood. So, often you’ll get a cold and your nose and your sinuses are infected, but your blood isn’t infected. Just this area. So, sepsis is top to bottom, you’re infected. Blood, kidneys, lungs, whatever. You’re sick. You’re really sick. Your chances of dying are very high.


Pneumonia is a next kind, and I think most people have a good idea of what pneumonia is. It’s when there’s an infection in your lungs. And then, bursitis is an infection in your shoulder, or elbow or hip. And then, complicated urinary tract infection. So, that’s when it’s not just a bladder infection, but when it’s spread. When it’s in the kidneys, and the urinary tract is infected.

Herpes Zoster

Then herpes zoster. So, most people think when they hear herpes, they think, “Oh, like a genital infection. Like a sexually transmitted disease.” And yes, it can be that. But it can also be like cold sores around your mouth. There can be other types of herpes zoster. And so, it’s a virus that’s hiding until it has a chance to get out. And prednisone is that chance it’s using to get out.


Then, varicella-zoster. And most people my age or older, got varicella-zoster as chickenpox as a kid. And then, the Varicella-Zoster can come back when you’re older and your immune system is suppressed, or you’re old or something. It comes back as shingles, which is a terrible, miserable rash with lots of pain. And it’s just miserable. Talk to anyone who’s had it, and they want to die. But it’s not usually fatal. You just feel miserable.

Fungal Infections

Then, we have fungal infections like mycosis and oral candidiasis. So, that’s when your tongue turns white, like the back of your tongue. Your whole mouth can turn white with a fungal infection. They often call that thrush. And so, these all have something in common and it is that you don’t normally see them in otherwise healthy people. It’s not like these things would happen otherwise, if you weren’t on the prednisone. So, like shingles, doesn’t normally happen unless you have a low immune system. So, basically these are all what they call an opportunistic infection. These viruses and fungus and bacteria are hiding, and they’re just waiting for their chance to pop out and pounce. Some of them you’re carrying on you. And then, once the prednisone lowers your immune system enough, they pounce. And they have their chance to make you feel sick.

What Was NOT on the List of Prednisone Side Effects

So, these infections, I want you to notice the one thing about this list I shared. Didn’t include colds,  flu, or strep. The typical things that my kids bring home from school, wasn’t on this list. And so, I’m not saying that prednisone can’t lower your immune system. And so, that you’re more likely to get those. What I’m saying is, the evidence that I can find, doesn’t show that it does. So, there’s no evidence showing that you’re more likely to get a cold or you’re more likely to the flu or you’re more likely to get another simple bacterial infection, like strep throat. It’s more these kind of bizarre, less likely things that are waiting for a chance!

So, it’s not necessarily as much the things that you would catch on a day to day basis, living in the Northern hemisphere in the wintertime. It’s more that you caught it when you were sexually active as a teenager. And now, it’s coming back as herpes zoster, coming back out of the latent phase. So, basically most of these infections are just waiting for the chance for prednisone to lower your immune system enough. There are some others like Kaposi Sarcoma and pneumocystis jiroveci pneumonia, and these really terrible and extremely rare things can happen too.

The Study of Short-Term Prednisone Use

And so, these are all possibilities. But they’re not necessarily that likely. So, let me tell you some information about what’s likely. One study showed and they looked at a million people in an insurance company. And they wanted to see what was the effect of just a short term dose of prednisone on your likelihood to have other things happen to you. So, it said that 21 out of a thousand users got fractures. Five out of a thousand users got a clot. And two out of a thousand prednisone users had sepsis. That’s the one I described as like your whole body is infected and you’re likely to die.

Even Short-Term Prednisone Causes Adverse Events

So, their question was, does short-term use lead to increased risks of infections or prednisone side effects? And they said that even short durations of use, regardless of dose, were associated with increased risks of adverse events. So, you’ll often hear doctors say, “there’s hardly any risk for you because you’re only on it short term,” or “you’re only on a low dose.” And that’s not really true. Even short-term, even low doses can increase your risk for things like fractures, sepsis, and clots. And so, there’s basically no safe way to use prednisone. And so, if you’re using it, you better have a really good reason to use it. Because it increases your risk for so many things.

  • Short-term prednisone use can cause side effects
  • Low doses can cause side effects

What you CAN do

Okay. Now, I want to empower you with what to do, when it comes to Infections and Prednisone Side Effects. If you are concerned that one of these things is happening to you, what can you do? Well, I think most people are aware of the typical signs of an infection, like swelling, redness. Like if your throat’s inflamed, your doctor can look and see how red and swollen it is. And so, you know those typical signs. But when prednisone is there, it’s masking some of those signs. They might not actually even show up. Like you might not get the redness. You might not get the swelling. Theoretically, you do still get a fever. Hopefully, if the rest of your immune system’s intact. So hopefully, the monocyte cells are still able to say, “Hey, we need to attack this and send the signal with a fever.” And so, look for a fever above 100.5.

Stay in touch with your Doctor

And if you get a fever, if you get typical signs of an infection, tell your doctor. Tell him what’s going on.

  • If you have flank pain from a urinary tract infection, so pain in your lower backend side.
  • Or you have a cough that just won’t go away.
  • Or this is really more common, your tongue is white. Like has little white patches in your mouth, your cheeks, on your palate. Look for that too.
  • If your herpes zoster or shingles comes back, definitely tell your doctor. Because there are things they can do to help it if you catch it at the very beginning. They can make it not quite so miserable.

So, my number one tip, is to stay in touch with your doctor.

Practice Good Hygiene and Be Cautious

My second tip is, while prednisone does increase your risk for these opportunistic infections, there’s no evidence showing that it increases your risk for cold and flu and your typical common infections. So, you don’t need to be like a complete, you don’t have to stay home all the time. You can still be around people, but you just need to take the precautions like washing your hands. And, you know what those are. What I want you to know is, you can still love your family, you can still be around them. You can still be around the people that matter to you. You just need to be watchful for signs of these random opportunistic infections that can happen.

2020 COVID-19 Update: What I stated in the article and video were true as of 2019. During the pandemic, please practice social distancing, wear masks, and take the precautions the health department recommends. 

And if you want more help with other side effects, I have a prednisone checklist. If you find this article helpful, you may check out my other blogs or sign up so we can send the latest news about prednisone!

Free Prednisone Checklist

  • This field is for validation purposes and should be left unchanged.

Read More about Prednisone Side Effects:

Dr. Megan Milne, PharmD, BCACP

Dr. Megan Milne, PharmD, BCACP, is an award-winning clinical pharmacist board certified in the types of conditions people take prednisone for. Dr. Megan had to take prednisone herself for an autoimmune condition so understands what it feels like to suffer prednisone side effects and made it her mission to counteract them as the Prednisone Pharmacist.

Related Posts