Blisters are a very common problem on the skin that occur from certain types of injuries. They can be very annoying, but they’re a natural healing mechanism of the body that should be allowed to run its course. Sometimes though, warts can be mistaken for blisters at the very start of an HPV infection. It can be very difficult to wait and watch to see which type of problem you are dealing with, so here are a few clues to help you figure out whether you are looking at a wart or a blister.

What is the Difference?

Warts are fleshy lesions caused by the HPV virus. They are contagious, and can occur in clusters of flat bumps or as a single wart. Blisters, on the other hand, are filled with fluid. They are not contagious and occur only because the skin has been injured in some way, as if with a sunburn or abrasion.

The fluid inside of the blister can be made of:

  • pus,
  • plasma,
  • serum,
  • lymph, or
  • blood.

A wart may look very similar to a blister in the beginning, and may even be filled with a very small amount of fluid as the skin’s infection is just beginning to set in. But the difference in appearance will begin to show within a few days as the skin over the wart grows thicker. A wart may also hurt a bit if squeezed from the sides, while a blister usually does not because it’s just a covering of dead flesh over pus or fluid, like nature’s band-aid.

About blisters
Blisters are your skin’s natural defense mechanism to help the tissue underneath heal. The fluid between the top layer of skin and lower level of epidermis prevents further pressure and abrasion. While you should always take measures to prevent them, once they occur, they should be left to heal on their own. They are safe and effective in protecting the skin as long as the fluid inside is clear. If you notice cloudiness, red streaks or oozing pus, the blister is most certainly infected. Time to see the doctor.
Blisters scheme

Plantar Wart vs Blister

Plantar warts may start as a blister like sore, and they often feel and look like blisters when they first start. It also may or may not hurt when it starts, but it will likely begin to become painful as it pulls in its blood supply and grows deeper into the sole of the foot. You will probably notice a dark spot in the center as this happens. As stated above though, blisters will resolve within a few days while a wart will last much longer.

Blisters on feetIt’s important to recognize that your sore spot might also be a callous, since they occur so often on the bottoms of the feet due to ill-fitting shoes or excessive walking. Calluses are very difficult to distinguish from plantar warts too, but you will notice one very definite difference. Calluses lack those little black dots that show the lesion is beginning to pull in extra blood supply for excessive growth.

If you see little black dots in what you thought was a callous, you almost definitely have a wart and should see a doctor to get it removed before it becomes very painful or difficult to walk. These little black dots are often called seed warts, because they look like tiny poppy seeds. You can read more about seed warts and their identification here.

My Foot

There are many things that can cause a blister to grow on your foot, such as:

  • wearing shoes that are too tight or ill-fitting,
  • repeated friction from a new exercise routine such as jogging,
  • heat burns,
  • bug bites (such as from fire ants),
  • chemical burns, and
  • cold burns (such as with dry ice).

5 Blister Stages

There is only one thing that can cause a wart, which is infection with the HPV virus. If you are positive that you have not been exposed to the HPV virus such as through a locker room floor, sharing shoes or grooming equipment or from another source and you have experienced any of the injuries listed above, then you might only have a blister. The body creates these blisters to cushion the skin beneath so that it can heal after receiving one of these types of injuries.

Don’t try popping the sore because it may become infected.

While a blister will tend to remain the same size, a wart will continue to grow. If it is a common wart, it will grow outward, develop a cauliflower like appearance and a slightly gray color. To learn more about common warts, you can read this article. A plantar wart will grow deeper into your foot, as stated above, and can become very large if left to grow unchecked.

My Toe

There are several different types of warts that can appear on the toe, depending on whether they appear on the top, bottom or side.

Blister on toeThese lesions can be:

  • large or small,
  • grayish, skin toned, white or brown,
  • long and protruding,
  • flat,
  • round,
  • rough, or
  • smooth.

That means that there’s no easy way to figure it out based on simple appearance. Even if it is smooth and looks like a blister, a wart is sometimes smooth too. But a wart will almost definitely feel a little harder or firmer than a blister with a little squeeze. You will likely feel the fluid on the inside of the blister (don’t squeeze it so hard it pops).

If it feels like fluid on the inside, you might just want to put a band-aid on it and wait it out for a few days. Time will tell ultimately, because a blister will heal and go away once it’s no longer being irritated. On the other hand, warts can take weeks or even months to finally resolve on their own.

How Do I Know Whether a Bump on My Hand is a Wart?

Just like with toes, skin warts on the hands can have many different appearances depending on where they are located and the type of HPV virus that is causing the growth. To learn more about how to identify different types of skin warts that can occur on hands or other parts of the body, check out this article.

DrScholl's Blister Treatment packBlisters on the other hand, are most likely to occur in the soft web between the forefinger and thumb. This is the part of the hand that is most tender to friction damage during work. They will also pop up anywhere on the hands that have been injured. If you remember burning yourself (such as with bacon grease while cooking), causing friction with chores or yard work or any other injury, you might just have a blister. You should, however, cover it and avoid popping it or getting it dirty until it resolves because blisters can become infected.

If your lesion is not filled with fluid and didn’t result from injury, it may still be something other than a wart. Calluses often pop up on the fleshy part of the palms directly underneath the knuckles. They occur as a result of driving, friction from your wedding ring or just every day labor. If there are no dark spots on the hard, thickened skin and it’s been there for a long time without changing much, it’s very likely just a callous.

Warning
It’s very tempting to poke at a lesion to see if it leaks fluid and is therefore a blister. You may even read some advice online advising you to poke at a sore in this way. Don’t. This is one of the easiest ways to introduce a dangerous infection. If you need a diagnosis, check with your doctor.

Understanding Genital Warts and Blisters

If you have blisters anywhere on your genitals, even if they are not warts, you absolutely need to see a doctor. This is because there are many other STD’s that can cause blisters as well, such as herpes. Both genital warts and herpes often appear to pop up as a cluster of blisters at first. However, herpes will develop a crust, much like a cold sore in appearance (which is caused by the herpes virus as well), and warts will develop into hard, cauliflower like lumps.

BlistersThis is not to say that the blisters on your genitals are not just that – blisters. Like every other part of the body, blisters on the genitals can be caused by excess friction, extremely ill fitting clothing or burns. If this is the case, they will simply resolve in a few days, but they should still be treated to avoid secondary infection which is very common in the genital area. Also, avoid all sexual contact until the blisters have resolved as you will be more vulnerable to contracting other infections until they heal.

If you are still not sure whether what you are dealing with is a blister or wart, it may be best just to let the doctor take a quick look at the lesion. It’s worth the peace of mind and can help you solve the problem faster with an accurate diagnosis.

You can find further details of Types of warts here.