About Blisters

Overview

A blister is a bubble of fluid that forms under the skin. It contains clear, watery liquid called serum, which is leaked from neighboring tissues as a reaction to injured skin. If left unopened, a blister can provide natural protection for the skin beneath it. There are different types of blisters based on their size and contents. Small blisters are called vesicles, while larger ones are called bullae. A blood blister is filled with blood instead of serum. Blisters can be caused by various factors including irritation from friction, chemicals, extreme temperatures, or burns. Allergic reactions, infections, certain skin diseases, and some medications can also lead to the formation of blisters. Blisters can occur anywhere on the body but are commonly found on the feet due to friction from ill-fitting shoes or prolonged rubbing.

Causes and Risk Factors

Blisters are caused by various factors, including:

Friction and pressure: Many blisters on the feet develop due to a combination of rubbing and pressure on the skin. Socks or footwear that do not fit properly can cause friction and rub the skin raw.
Burns and sunburns: Skin that blisters from heat is considered a second-degree burn
Frostbite: Blister may occur when warming up after frostbite.
Injury: Something pinching the skin may result in a blood blister.
Autoimmune diseases: The body’s immune system attacks healthy skin; examples include pemphigus and bullous pemphigoid
Allergic reactions, including poison ivy, oak, and suman
Skin infection and eczemas

Modifiable risk factors:

Footwear and socks: Wearing poorly-fitting footwear or socks made of synthetic materials can contribute to blister formation.
Activity level: Engaging in activities that involve long-distance walking/running or friction to unprotected hands (for example, rowing a boat) can increase the risk of blisters.
Foot abnormalities: Certain foot abnormalities can impact the fit of shoes or socks, increasing the likelihood of blisters.

It's important to note that these risk factors are not exhaustive, and individual circumstances may vary. If you have concerns about blisters, it is best to consult with a healthcare professional for personalized advice.

Symptoms

Common symptoms of blisters include:

Round or oval bubbles of fluid under the skin
Pain or itchiness in the affected area
Redness and swelling around the blisters
Small bumps on the skin

Additional symptoms may occur, depending on the underlying cause:

For blisters caused by friction or burns: increased pain, tenderness, and difficulty moving the affected area
For blisters resulting from eczema: severe itching, redness, and the development of small bumps on the skin
For blisters caused by infections (such as herpes simplex virus): itching, tingling, swelling, and redness before the blisters appear; eventual bursting of the blisters, leading to painful sores

In some cases, certain types of blisters may also cause specific symptoms:

Diabetic blisters: clear bumps that primarily appear on the legs, feet, arms, and hands; itching sensation; healthy-looking skin around the blisters
Epidermolysis bullosa (EB): blistering on the skin, scalp, eyes, and nose; thin and fragile skin; hair loss; small white bumps on the skin; nail loss or deformity; excessive sweating; breathing difficulties if blistering occurs in the throat

Warning signs: Most blisters do not necessitate seeing a healthcare professional. A healthcare professional should be consulted if the blister shows signs of infection, such as being pus-filled, pain and redness around the blister.

It's important to note that these symptoms can vary depending on the individual and underlying cause. If you experience any concerning symptoms or have questions about your condition, it's best to consult with a healthcare professional.

Diagnosis

To diagnose blisters, doctors typically rely on a combination of physical examination and medical history. However, in some cases, additional examinations, tests, and procedures may be performed to determine the cause or severity of the blisters. Here are some commonly used diagnostic methods:

For initial diagnosis:

Medical history: Questions about family history, allergies, medications, and recent exposures to irritants or allergens.
Physical examination: Doctors examine the appearance and location of the blisters.

Additional tests and procedures:

Patch tests: Used to identify potential allergens by applying chemicals to the skin.
Skin biopsy: A small piece of tissue is removed and examined under a microscope to determine the cause of the blisters.
Direct immunofluorescence microscopy: Detects deposits of immunoreactants in the perilesional skin.
Indirect immunofluorescence on salt-split skin: Provides information on autoantigens at the dermal-epidermal junction.
Immunoblotting: Detects autoantibodies against specific antigens.

Additional examinations, tests, and procedures maybe performed to determine the underlying cause or severity of the blisters. It's important to consult with a healthcare professional for personalized advice and guidance.

Treatment Options

The goals of treatment for blisters depend on the underlying cause and location. Here are the different treatment options and how they work to achieve those goals:

Self-care: Blisters often heal on their own within a few days. To care for them:

Wash the area with a mild soap
Apply an antibiotic cream or ointment
Cover the blister loosely with a bandage or gauze. For blisters in high friction areas, such as the feet or toes, moleskin or gel-filled blister bandages may help reduce further friction or rubbing.
Change the bandage or other blister covering at least once per day.

Additional treatments may be recommended based on the type of blister.

Medications:

Corticosteroids: These anti-inflammatory drugs, available as creams, pills, or injections, help reduce inflammation and promote healing.
Immune suppressants: Drugs like azathioprine and mycophenolate mofetil prevent the immune system from attacking the body's own tissues, reducing blister formation.
Antibiotics, antiviral drugs, and antifungal medicines: These medications prevent infection if blisters break open.

Therapies:

Medicated mouthwashes: Recommended for blister treatment on the tongue, these help reduce inflammation and promote healing.
Topical therapy: This involves applying creams or ointments directly to the affected area to soothe the skin and aid in healing.

Therapeutic procedures:

Hospitalization: If blisters cover a large area of the skin, hospitalization may be required for close monitoring, wound care, and prevention of infection.

Health behavior changes:

Good oral hygiene: Regularly rinsing the mouth with warm salt water or using mouthwash can speed up recovery and prevent future oral blisters.
Proper wound care: Keeping blisters clean, dry, and covered with sterile dressings can aid in healing and prevent infection.

Remember to consult your doctor before trying any home remedies or over-the-counter medications. Medication dosing may be affected by many factors. Check with your health care professional about dosing for your individual situation. Side effects can occur. Check with your health care professional or read the information provided with your medication for additional side effect information.