Foot blisters are small pockets of fluid (serum, plasma, blood, pus, or lymph), and can vary in size and severity. Learn about foot blister symptoms and causes.
10 most common cause(s)
Foot blister symptoms
Americans average fewer than 5,000 steps per day. While this is below the recommended amount, it's still an awful lot of work for your feet. Because of their consistent use, injuries to the feet are not uncommon. One of the most annoying is the dreaded foot blister. How concerned should you be about a foot blister? Before we can answer that, let's see how many associated foot blister symptoms you're experiencing.
Common accompanying symptoms of foot blisters
It's likely to also experience:
- Pain from pressure
- Raised portion of the skin
- Light bleeding
- Swelling
- Redness
- Difficulty walking
Classified as small pockets of fluid (possible fluids include serum, plasma, blood, pus, or lymph,) blisters can vary in size and severity. Getting a foot blister is easy. Luckily, the treatment for one is also simple. Before you whip out ointment and a band aid, determine the actual cause of your blister. This will ensure that you receive proper treatment and that preventative measures are taken to avoid a second occurrence.
Foot blister causes
There are obvious foot blister causes, like excess friction, and some surprising reasons, like chemical exposure.
Trauma
Trauma to the foot can result in blisters due to the following.
- Friction: Pressure and friction can lead to blisters. Whether you stand or walk for hours on end, a change in your normal activity level can irritate the skin and lead to a bubble.
- Unsafe conditions: Exposing your foot to extreme conditions, both hot and cold, can lead to blisters. Frostbite is one example. After skin has thawed from excessively cold temperatures, blisters typically form. Sunburn and overly hot water can also cause blisters.
Reactions
Blisters can occur due to reactions to certain exposures.
- Allergic: Whether it's from direct contact or due to a skin condition like dyshidrotic eczema, blisters can form on the feet due to an allergic reaction. These can last for several weeks and the allergen must be removed.
- Chemical: Chemical burns range in severity but most require some degree of medical intervention. Blisters are one side effect of a chemical reaction, along with peeling and red skin.
Infections
Infections can result in blisters, such as the following.
- Fungal: The foot is an ideal breeding ground for fungi. Athlete's foot and ringworm are just two examples of fungal infections that can cause foot blisters.
- Bacterial: A cut on the foot that becomes infected with bacteria can develop a blister. Look for signs of a serious infection, like pus or red lines.
Environmental foot blister causes
Lifestyle habits or certain exposures can result in blisters.
- Moisture changes: Walking around in wet socks or going on vacation in a drier climate than you're used to are two ways your skin's moisture levels can be agitated, leading to blisters.
- Clothing: Wearing itchy socks or shoes that are too tight can cause friction that leads to foot blisters.
Frostbite
Frostbite of the feet and toes can also cause blisters to form. Frostbite occurs when the feet are exposed to very cold temperatures, and it doesn't necessarily take prolonged exposure to get frostbite. In places where the temperature is 0 degrees Fahrenheit with a 15-mph wind, frostbite can occur in 30 minutes or less.
Burns
On the other end of the temperature spectrum, burns to the feet can cause blisters as well. If you step on something hot and your feet suffer a second-degree burn, you will likely see a blister form immediately. Blisters can develop from a first-degree burn as well, but these blisters often take a few days to appear.
Poor-Fitting Shoes
Poor-fitting shoes are a major cause of blisters of the feet, and it's not just high heels that are to blame. In fact, any style of shoe that pinches the feet or that rubs in a sensitive area can cause blisters.
Dyshidrotic Eczema
A rarer cause of blisters on the soles of the feet is dyshidrotic eczema, which is a skin condition that has connections to both stress and allergies. This condition is most common during the spring allergy season, and the blisters tend to form around the edges of toes and feet. It can take a few weeks for dyshidrotic eczema blisters to dry up and heal.
This list does not constitute medical advice and may not accurately represent what you have.
Non-specific skin rash
Nonspecific skin rash means any sort of unexplained outbreak on the skin.
Common causes of rash are contact dermatitis, sun damage, or allergic reaction. However, many rashes are a symptom of disease and should not be ignored.
Nonspecific rashes have widely varied symptoms:
- May be flat and smooth; slightly raised or with swollen welts; clean and dry; or blistered and oozing.
- May spread widely over the body, or be confined to one site.
- May appear after eating certain foods; or after exposure to certain plants or to insect stings or bites.
- Other symptoms may be present, including pain anywhere in the body; nausea; vomiting; fever; headache; or abdominal pain and upset.
Diagnosis is made through patient history and physical examination to determine the exact type, location, and history of the rash, along with any other symptoms that may be present.
Those symptoms will be investigated with blood tests or imaging. Skin swabs may be taken and tested. After the process has ruled out as many causes as possible, a course of treatment can be determined.
Molluscum contagiosum
Molluscum contagiosum, also called "water warts," is a common, benign, viral skin infection. It causes a rash of bumps that may appear anywhere on the body.
The virus spreads through direct contact with the bumps, including sexual contact. It also spreads through touching any object that an infected person has handled, such as clothing, towels, and toys.
Most susceptible are children under age 10. Other risk factors include dermatitis causing breaks in the skin; a weakened immune system; and living in warm, humid regions under crowded conditions.
Symptoms include a rash of small, pale bumps with a pit in the center. The rash is usually painless but may become reddened, itchy, and sore.
Diagnosis is made through physical examination.
In some cases, treatment is not needed and the condition will clear on its own. However, if the bumps are unsightly or are present in the genital area, lesions can be removed through minor surgical procedures or treated with oral medication or topical agents.
Irritant contact dermatitis
Irritant contact dermatitis means a skin reaction that is caused by directly touching an irritating substance, and not by an infectious agent such as a bacteria or virus.
Common causes are soap, bleach, cleaning agents, chemicals, and even water. Almost any substance can cause it with prolonged exposure.
Contact dermatitis is not contagious.
Anyone who works with an irritating substance can contract the condition. Mechanics, beauticians, housekeepers, restaurant workers, and health care providers are all susceptible.
Symptoms include skin that feels swollen, stiff, and dry, and becomes cracked and blistered with painful open sores.
A medical provider can give the best advice on how to heal the skin and avoid further irritation. Self-treatment can make the problem worse if the wrong creams or ointments are used.
Diagnosis is made through patient history, to find out what substances the patient comes into contact with, and through physical examination of the damaged skin.
Treatment involves avoiding the irritating substance if possible. Otherwise, the person can use petroleum jelly on the hands underneath cotton and then rubber gloves.
Friction blister on the foot
Friction blisters are very common among both men and women of all ages. They most commonly affect the feet due to lifting heavy loads, repetitive overuse, or ill-fitting shoes. The layers of skin become separated from mechanical force, and the body fills the gap with fluid.
Friction blisters will heal on their own, however they can become infected if not properly cleaned. Soap and water followed by topical antibiotics will help to prevent infection. Additionally, a bandage will both keep the blister clean and help with discomfort. Do not attempt to pop a friction blister.
Rarity: Uncommon
Top Symptoms: foot pain, foot blister, blister likely from friction, constant skin changes, foot skin changes
Symptoms that always occur with friction blister on the foot: foot blister, blister likely from friction
Urgency: Self-treatment
Diabetic neuropathy
Diabetic peripheral neuropathy is the damage done to nerve fibers in the extremities by abnormally high blood sugar. Anyone with diabetes is at risk for peripheral neuropathy, especially if the person is overweight and/or a smoker.
Symptom include pain, numbness, and burning in the hands, arms, feet, and legs; muscle weakness; loss of balance and coordination; and infections, deformities, and pain in the bones and joints of the feet.
Peripheral neuropathy can develop very serious complications, since the high blood glucose prevents any infection or damage from healing as it should. This can lead to ulcerated sores, gangrene, and amputation. For this reason, signs of peripheral neuropathy are considered a medical emergency and the person should see a medical provider as soon as possible.
Diagnosis is made through sensitivity tests and nerve conduction studies.
There is no cure for diabetic neuropathy, but the symptoms can be managed in order to slow the disease and help restore function. Treatment will include lifestyle improvements and the use of pain medication.
Cellulitis
Cellulitis is a bacterial infection of the deep layers of the skin. It can appear anywhere on the body but is most common on the feet, lower legs, and face.
The condition can develop if Staphylococcus bacteria enter broken skin through a cut, scrape, or existing skin infection such as impetigo or eczema.
Most susceptible are those with a weakened immune system, as from corticosteroids or chemotherapy, or with impaired circulation from diabetes or any vascular disease.
Symptoms arise somewhat gradually and include sore, reddened skin.
If not treated, the infection can become severe, form pus, and destroy the tissue around it. In rare cases, the infection can cause blood poisoning or meningitis.
Symptoms of severe pain, fever, cold sweats, and fast heartbeat should be seen immediately by a medical provider.
Diagnosis is made through physical examination.
Treatment consists of antibiotics, keeping the wound clean, and sometimes surgery to remove any dead tissue. Cellulitis often recurs, so it is important to treat any underlying conditions and improve the immune system with rest and good nutrition.
Rarity: Uncommon
Top Symptoms: fever, chills, facial redness, swollen face, face pain
Symptoms that always occur with cellulitis: facial redness, area of skin redness
Urgency: Primary care doctor
Bullous impetigo
Bullous impetigo is a skin infection that causes large blisters that is caused by streptococcus (strep) or staphylococcus (staph) bacteria. Methicillin-resistant staph aureus (MRSA) is becoming a common cause.
You should visit your primary care physician within the next 24 hours, where your doctor can make a diagnosis by looking at the rash. Most of the time, impetigo gets better without requiring medical care, but doctors do prescribe topical antibiotics. Oral antibiotics are given for more serious manifestations.
Rarity: Common
Top Symptoms: moderate fever, constant skin changes, facial skin changes, severe fever, crusty rash
Symptoms that always occur with bullous impetigo: facial skin changes, constant skin changes
Urgency: Primary care doctor
Benign skin growth
Benign skin growths are very common and virtually everyone has some form of them. "Benign" means the growth is not cancerous and not harmful. Some of these growths have genetic origins, and for some the cause is not clear.
Common types are:
- Birthmarks, may appear as flat "stains" in the skin or as raised clusters formed of tiny blood vessels.
- Moles, small irregularities that originate in the pigment-producing cells in the skin. They can be almost any shape or color but are normally no larger than one-quarter of an inch across.
- Skin tags, little irregular flaps of skin, like a flattened mole attached on only one side.
- Keloids, a dark, fibrous form of scar tissue that forms after a skin wound, either from trauma or from surgery.
As a person ages, more changes may appear in the skin. Most are benign, but any unusual or suspicious skin growth should be checked by a medical provider. The growth can be removed if it is unsightly, interferes with clothing, or proves to be malignant (cancerous.)
Athlete's foot (tinea pedis)
Athlete's foot is a common fungal infection of the feet and/or toes. Warm, moist environments and community showering are common causes of this type of infection.
Over-the-counter treatments are quite effective at treating athlete's foot. They can come in the form of sprays, ointments, or even oral antifungals. Consider replacing shower footwear and bleaching any bathroom floors.
Allergic reaction to poison ivy/oak/sumac
Plants of the Toxicodendron genus are found throughout the continental United States, and exposure to these plants is a leading cause of contact dermititis, a medical term used to describe irritation and itching of the skin.
Firstly, to prevent allergic reaction to poison ivy from getting worse, wash the affected area thoroughly with soap and water. Over-the-counter antihistamines such as Benadryl can help with the swelling and itching. Topical corticosteroids applied directly to the rash can also help relieve some of your symptoms
Rarity: Common
Top Symptoms: rash, itchy rash, red rash, skin changes on arm, stinging or burning rash
Symptoms that always occur with allergic reaction to poison ivy/oak/sumac: itchy rash, rash
Symptoms that never occur with allergic reaction to poison ivy/oak/sumac: fever
Urgency: Self-treatment
Foot blister treatments and relief
As mentioned, a trip to the doctor is rare when it comes to foot blister cases.
How to address a blister at home
You may want to treat foot blister symptoms as quickly as possible, but before you reach for a needle or pick at it with your finger, keep the following in mind.
- Limit your infection risk: Only pop a blister if it is likely to be further irritated. The skin beneath should be kept clean to prevent infection.
- Sterilize a needle: If you feel popping the blister is necessary, use a sterilized needle to make a small hole and allow the fluid to drain.
- If the fluid is anything but clear, an infection is likely
- Apply an antibiotic cream to the area
- Monitor the area: You should watch for signs of infection until it has cleared. If necessary, seek medical attention for an infection that becomes overly painful or worsens.
Bandages and Gauze
To protect a blister and allow it to heal, cover it up with a bandage or wrap it in gauze. It can be difficult to keep bandages on the feet due to sweat and wearing shoes. So wrapping gauze around a foot blister is often a more effective approach. Hydrocolloid dressings are an over-the-counter solution to promote blister healing and manage blister pain.
Fresh Air
When you are home and not on your feet, remove the bandage or gauze to allow fresh air to reach your blister. This will reduce the amount of moisture on your feet and promote faster healing.
Blister Taping
Rather than waiting for blisters to form before bandaging your feet, you can preemptively tape then to prevent blisters instead. Long-distance runners and other endurance athletes commonly tape their feet to protect the skin's surface from rubbing. Research has also shown that taping the feet can provide thermal insulation and spread the shear load when using stretchy tape.
Aloe Vera
Aloe vera is commonly used for sunburns, but its soothing and anti-inflammatory properties make it excellent for foot blisters too. Much of the pain of a blister comes from the swelling, and aloe vera is known to reduce inflammation. You can either buy commercially packaged aloe or cut a leaf off an aloe plant in your home.
When to see a doctor for foot blister symptoms
If you notice the following foot blister symptoms, schedule an appointment to be safe.
- Continual drainage of pus
- Severe pain when applying pressure
- A blister that keeps coming back
- Any other sign of infection: Such as redness or excessive warmth.
Further at-home treatments for foot blister symptoms
If you're avoiding the needle (which is recommended), here are a few ways you can regulate your discomfort and speed up the healing of your foot blister symptoms.
- Avoid pressure: When making major changes to your activity levels, try to do so gradually. Avoiding excess pressure on your feet will help prevent blisters in the first place and speed up the healing of any existing ones.
- Change clothing: Opt for cotton socks that let your feet breathe and avoid shoes that don't fit just right.
- Witch hazel: Witch hazel's astringent tannins will help dry out a foot blister without taking the risk of popping it. Apply it gently using a cotton ball.
The next time you spot a bubble on your foot, you can assume a blister is brewing. By taking the proper steps, you can speed up its healing and prevent infection.
FAQs about foot blisters
Should you pop a blister on your foot?
Friction blisters on the foot occur when repeated trauma and shear forces separate the epidermis and dermis of the foot. These blisters tend to resolve normally without intervention and should not be popped. If possible, a bandage that surrounds the blister and takes pressure off of it is the best way to treat the blister while avoiding further injury or infection.
Is there a safe way to drain a blister?
Generally, the principles of any type of wound treatment apply to a blister. Use sterile tools cleaned with a disinfectant or heat-treated to lance and drain a blister and then remove excess skin. The blister can then be treated with a dry bandage. You should avoid using dirty tools and treating a blister with wet salves.
How long does it take for a blister to heal?
A blister, once properly treated, should heal anywhere from seven to ten days. If the blister begins to become inflamed or emit pus, it may be infected and you should seek medical care and possibly antibiotics. It is, however, uncommon to contract an infection as long as the wound is kept dry and clean.
What is the fluid in a blister?
Blisters can contain many different types of fluids or mixtures of fluids. The most common types of fluids include plasma (or blood without the red blood cells), blood, lymph (the fluid from the lymphatic system generally full of white blood cells), and pus if the blister is infected in some way.
Why do my blisters hurt?
Blisters hurt because the epidermis, the top layer of the skin, generally dulls sensation but has been pulled loose from the underlying layers. These layers, called the dermis, hold more nerves and can therefore register more sensations of pressure and pain. Even a light touch feels painful without the protection of the epidermis over the more sensitive dermis.
Questions your doctor may ask about foot blister
- Do any of your body parts (e.g., toes, hands, ears) feel cold?
- What fluid is in your blister?
- Are you having any difficulty walking?
- Do you drink alcohol?
Self-diagnose with our free Buoy Assistant if you answer yes on any of these questions.
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References
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