Infected Blister? How To Tell & What To Do About It

infected blister on toe lance pus

If getting a blister isn’t bad enough, the last thing you need is for it to get infected. An infected blister gets worse before it gets better. It becomes red and painful, takes longer to heal, and as you'll see at the end of this article, can lead to some very nasty consequences.

What Does A "Healthy" Blister Look Like?

A normal healthy blister contains thin watery blister fluid that is colourless or a very light yellow colour. Blister fluid will be pink or red in the case of a blood blister. However, pink/red doesn't mean your blister is infected. All it means is damage has occurred to a small blood vessel and blood has leaked into the blister. Rest assured, these blister presentations are considered normal and uninfected.

Normal healthy uninfected blister

Normal (non-infected) blister fluid is thin and clear, like this.

What Does An Infected Blister Look Like?

There are some tell-tale signs that your blister is infected.

  • Pus: Instead of thin colourless blister fluid, an infected blister contains a thicker cloudy yellow or green fluid called pus.
  • Redness: The immediate area of skin around the blister is often red, and in fact, this redness worsens over time.
  • Swelling: The immediate area of skin around the blister may be a bit puffy. Again, this swelling worsens over time when there is infection.
  • Pain: There will likely be increased tenderness that gets worse rather than better over time.

See how the blister fluid here is yellow - this is actually pus. Pus occurs when there is bacterial infection.

How To Treat An Infected Blister

Most infected blisters can be successfully treated at home without the need for medical consultation. It’s very easy to do yourself. All you need is the right products and diligence in monitoring your blister for changes. Here’s what you need to know…

Products You’ll Need:

✔️ Clean Hands

Wash with soap and water or rubbing alcohol

✔️ Sterile Lancing Implement

I like using a scalpel blade or hypodermic needle. Don’t use a heated pin or sewing needle over a flame for these reasons.

✔️ Cotton Buds

To gently ease any blister fluid out, to wipe debris from your blister and to apply your antiseptic / antibiotic.

✔️ Cottonwool or Gauze

To wipe debris from your blister, soak up any blister fluids and dry your blister before applying your dressing.

✔️ Antiseptic or Antibiotic

Either antiseptic solution such as povidone iodine, or antibiotic ointment such as Neosporin. Along with your body’s immune system, these products will kill the germs in your blister.

✔️ Island Dressings

To protect the blistered skin and keep new germs out.

Get It All In Our Sterile Blister Lance Pack

You can pick up our Sterile Blister Lance Pack here. It contains everything you'll need for 4 blister lancing/treatment episodes.

Treatment Procedure For Intact, Torn or Deroofed Blisters

If Your Infected Blister Is Deroofed:

Simply wipe any debris away, apply your antiseptic/antibiotic and cover it with an island dressing. Don’t forget, we’ll be monitoring it closely over the next few days.

If Your Infected Blister Is Torn:

Be sure to remove as much debris as you can from under your remaining blister roof. This debris is harbouring the very bacteria you are trying to kill. Physically removing it is a high priority. Make sure your antiseptic/antibiotic gets into all the nooks and crannies under your blister roof. I like to use a liquid for this reason.

If Your Infected Blister Is Intact And Full Of Pus:

It is advisable to lance and drain the infected blister, and then follow the above steps. I have several blister lancing videos here showing you how to perform the procedure easily, safely and painlessly.

The Importance Of Monitoring Your Infection

Your infection won’t clear up immediately after one episode of the above procedures. In fact, the infection may not clear at all. That’s why we have to monitor our infected blisters closely and repeat the above procedures.How often? Twice a day should be enough. Change your dressing more often in the following situations:

Your Dressing Gets Wet:

The last thing you need is a soggy dressing sitting on your infected blister all day. Take the wet one off, apply some more antiseptic/antibiotic and put a nice clean one on.

You Notice Strikethrough:

Strikethrough is evident when your blister exudates (fluid, pus, blood etc) have soaked right through the island of your dressing. As soon as strikethough happens, bacteria can travel through your dressing. Take the dirty one off, apply some more antiseptic/antibiotic and put a nice clean one on.

When Medical Urgency Is Required

Infected blisters can morph into a more urgent situation that requires medical attention. At this point, you’ve not managed to get on top of this infection. The infection is spreading from the immediate area to involve other bodily systems and functions. You need to see a doctor *today* with your infected blister if:

  • After 3 days your blisters continue to become more red, swollen, painful and weepy.
  • You see reddish streaks radiating from your blister.
  • You have a fever or chills

Possible Complications

An unchecked blister infection can lead to serious health conditions. People have actually died or lost limbs due to infected blisters. President Coolidge's son Calvin Jr. died at 16 years of age in 1924 due to an infected blister on the top of his 3rd toe right foot from playing tennis with his brother. At this time, penicillin was yet to be discovered. But antibiotics are around today so there's no excuse for sitting on your hands while your infected blister gets worse and worse. In the modern day, many famous people, from models to sports stars, have felt the effects of blisters that get infected. Here's an example from Kate Miller-Heidke on Twitter after Eurovision:For anyone interested, I was diagnosed with cellulitis resulting from an infected blister. It’s the exact same disease Hilary Swank got while training for Million-Dollar baby so it’s definitely the most glamorous foot infection going around.And blisters are often the starting point of an amputation in people with diabetes and peripheral neuropathy.Here's what you need to know...

Cellulitis:

Cellulitis is a serious and painful skin infection that occurs when bacteria penetrate into deeper layers of the skin. It often requires hospitalisation and oral or intravenous antibiotics. At this stage, you'll be starting to feel unwell. And it's only going to get worse during the following escalations.

An infected blister can lead to cellulitis

Cellulitis (Flickr mikeblamires/125281197) - The black line has been dawn. With cellulitis, the demarkation between affected and unaffected skin is often quite definite.

Lymphangitis:

Red streaks around your blister indicate lymphangitis. This isn’t blood-borne infection, but the infection is starting to spread into the superficial lymphatic vessels. This is a warning that you need to see a doctor about this infection today. If you don’t, the following more serious health conditions may result.Infected blister can lead to lymphangitisLymphangitis - red streaks eminating from the source of the infection (James Heilman, MD)

Bacteremia:

This is the medical term for blood-borne infection. The bacteria have entered the bloodstream and now passing through your organs. Clearly, this is not good. At this stage, you're really crook, and you're feeling it!

Sepsis:

By now, you are drastically unwell! In fact you might not know much about anything at this stage due to your altered mental state, along with the fever, low body temperature, rapid heartbeat and breathing difficulties. These symptoms are all part of the infection's assault on your organs. Urgent specialist medical care is required. Call an ambulance!

Moral Of The Story

Look after your blisters, people!

Give Your Blister Excellent First Aid

Prevent infection with the Blister KitsSterile Blister Lance Pack

Comments & Questions

  • Wa
    Wade
    11 Nov, 2024

    This blister is on my foot right on my heel. It burns it's red this is day three I don't think it's healing. Or idk should I go to the emergency?.
    ****

  • Ca
    Carina rosales
    6 Jul, 2021

    Yes I have an infected blister it got more red and swollen its painful I need to see a doctor

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Go for it. All the best!

  • Em
    Emily Yago
    3 Aug, 2021

    Is there a way to cure a small infected blister without draining it? I don’t like needles and I’m too busy to be able to let a popped blister heal.

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Yes, leave it be and let mother nature do her thing. If it’s small and you can take away the blister-causing forces so it doesn’t recur, your immune system will fight it and resolve it. And if for some reason it doesn’t and it gets worse, this article has shown you how to recognise that and what to do about it.

    Hope this helps, Emily :)

  • Em
    Emily Yago
    3 Aug, 2021

    Thank you! One more question, though! What’s going on if it doesn’t change? It’s small but it isn’t getting bigger nor smaller? Thank you so much!

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Could be tonnes of things Emily, from allergies to fungal infections, psoriasis, a bite or more. I help people with friction blisters, so if it’s not that, I’m not much help I’m afraid.

  • Em
    Emily Yago
    3 Aug, 2021

    So sorry to bother you again. It is a friction blister! What typically counts as small? And, it doesn’t hurt except for when I touch it with a lot of pressure (even when I do it’s not that much), and the skin around it is extremely hard. Does it seem to be okay?

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    I think you should get some in-person advice Emily to help you understand:
    a) if it’s a friction blister
    b) if it’s infected
    c) and what you should do about it

    (edited)
  • Ca
    Cati
    9 Nov, 2021

    Hello I got a blister from wearing heels on Saturday on both my big toes, the one on my right toes heel by Monday. My left toe got more swollen it’s red and hot around the blister, if I stand it gets more swollen. What should I do?

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Hi Cati. I’ve laid out as much information as I can around this topic. I’ll leave it to you to apply it as you see fit to your situation. The fact that you’re still unsure suggests to me that you should seek medical advice on the topic of infection. If you want to know more about big toe blisters, refer to Big Toe Blisters: Types, Causes & Prevention

  • Ch
    Charli
    18 Nov, 2021

    Hi, I have several clustered big blisters on just one finger, the go prescribed antibiotics, but the whole finger is now swollen and some of the top of my hand is too, my whole hand feels bruised and tender and the pain is travelling up my arm. What is the appropriate thing to do, go to the gp again or go to hospital, I also don’t feel right

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Hospital

  • Ja
    Jay Jones
    20 Nov, 2021

    I’ve got a blister that was red in the center and a white ring around the outside. Today that white ring has seemed to pop under my skin and spread. Now it looks like a whiteish grey blister with a dark red blister in the center. What does this mean and how do I take care of it properly?

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Don’t know, Jay. Sounds weird. Get it checked out if you’re worried.

  • Ja
    Jay jones
    21 Nov, 2021

    Is there any way I could send you a picture so you could look at it? The one corner seems to of popped but none of the white fluid is coming out. But I can move the fluid around, it just won’t come out of the hole. Currently there’s very little redness, though there is swelling, and it itches more then hurts.

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    I’m afraid I don’t feel comfortable advising on something that is atypical and doesn’t sound like a friction blister on the foot – the topic of this website. Please seek in-person medical advice, Jay.

  • Ja
    Jamie
    30 Dec, 2021

    I’ve been walking for a while and ended up getting what I believe is a roof intact friction blister. It’s not painful and only causes a bit of discomfort but I’m afraid that if I continue to go on my long walks, it’ll get worse and possibly infected. I don’t know if I should give up walking for a couple of days in order to let my blister heal, what should I do?

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Hi Jamie. You’re right, if you don’t do anything to take away the blister-causing forces, your blister will likely get worse and tear, opening it up to the chance of infection.

    The idea is to negate the blister-causing forces. Sure, you could stop walking. Or you could do things like 1) reduce friction, 2) reduce pressure, 3) minimise movement of the adjacent bones, 4) spread shear load or 5) use shear-absorbing materials – and keep walking, without the risk of things getting worse.

    Which of the 5 options you choose depends on where your blister is (back of heel, between toes, outer pinky toe, under big toe, arch etc). Go to my blog and use the search function in the sidebar to search your blister location and I’ll tell you which are the best preventive options.

    Hope this helps.

    ~ Rebecca

  • Al
    Alexander
    19 Jul, 2022

    Thank you for your advice and recommendations, very useful even all the way in Scotland 😎

    (edited)
  • An
    Angelica Figueroa
    24 Jul, 2022

    So a popped blister still has a thin membrane of pus over it but it hasn’t come away. Stretched the skin and you can see the hole of the infected area but again the pus over it won’t wipe off. Should it just left there until it heals and falls away on its own or is there a way to remove it

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    “Thin membrane of pus over it that hasn’t come away”? “You can see the hole of the infected area”?
    I’m afraid I can’t even picture what’s going on, Angelica. But if you feel it’s infected and not resolving, you should seek in-person medical advice.

  • St
    Steven
    31 Jul, 2022

    Hey, im just wondering if my blister contain any fluid or not, because it acts like it doesnt have any fluid (empty with only air) friction blister

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Maybe the fluid has reabsorbed – that’s the ideal outcome.

  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Maybe the fluid has reabsorbed – that’s the ideal outcome.

  • Ol
    Olivia Malouf
    6 Oct, 2022

    Hi I have a blister on my hand which not infected but have prominent red streaks down to my wrist

    (edited)
  • Ch
    chelan
    3 Jun, 2023

    hi I have a blister and green fluid is coming out this happened to me before on my finger and I wnt to know what to d plz help me

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    ’Tis infected. Please seek medical advice.

  • Ch
    Chris
    15 Jun, 2023

    I just received cryogenic wart surgery and the blister is huge. Overnight it becomes dry on the outside and quite painful. I’ve been draining it through a pin prick with the membrane still intact. It’s 24 hours later and now very tender too the touch. Is that normal or infection? It’s not draining clear fluid anymore but a slight milky color.

    (edited)
  • Bo
    Bonnie
    4 Jul, 2023

    Hi, I just have one question for you. So I got a blister on the left side of my arch on my right foot 3 days ago. It’s deroofed because it’s from ice skating and it started bleeding. The new and reformed skin keeps coming off when I change the island dressing and I don’t know what I should do. It’s bloody and very hard to walk right now and I am starting school again soon. Should I get it check out by a medical professional or should I wait a few more days and see what happens?

    (edited)
  • Re
    Rebecca Rushton Bsc(Pod)
    20 Oct, 2023

    Okay, let’s work through this, Bonnie.

    You said it’s deroofed because it’s from ice-skating and started bleeding.

    • Just because you got this ice-skating doesn’t mean it’s deroofed.
    • Just because it has bled doesn’t mean this is deroofed, it could be torn.
    • This matters because it changes which dressing to use. Watch this:
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