13 reasons why you can get blisters on the skin

Blisters occur as a defense mechanism against injury to the superficial layer of the skin. A raised, liquid-filled portion is generated.

Written and verified by the doctor Mariel mendoza on December 08, 2021.

Last update: 08 December, 2021

Blisters are a raised, fluid-filled portion of the skin that can appear for various reasons. They are located in the epidermis (the most superficial layer of the skin) and are produced as a defense mechanism against aggressions.

It is a lesion with edema, elevated, palpable and circumscribed. It has liquid inside, which under normal conditions is light in color.

From a technical point of view, the term is used blisters or bullae when the lesion is greater than or equal to 0.5 centimeters in diameter. On the other hand, we talk about vesicles or fights if the size is smaller.

What do blisters look like on the skin?

Blisters are visualized as bags filled with a clear liquid, practically transparent, under the most superficial layer of the skin. Due to the underlying inflammatory process, the surrounding area may be red.

When they are full of blood, the liquid is red or black. Symptoms of pain, warm surrounding area, and purulent fluid (green or yellow) suggest a possible associated infection.

When the reasons for blisters on the skin derive from their presentation in unusual places, such as the eyelids or genitals, it is advisable to see a doctor. In the same way, when they are caused by burns, frostbite or an allergic reaction.

Blisters burst or break spontaneouslyand the liquid dries to a bright yellow crust. They should not be attempted to be broken manually, as their purpose is to protect the most superficial layer of the skin while it heals.

In most cases, blisters drain on their own over 1 to 2 weeks. It will not always be necessary to see a doctor. If the cause is known, the ideal is to cover the blisters with dressings or bandages to avoid friction.

When blisters appear due to burns, a specialized consultation is necessary to determine the approach.


Reasons for blisters on the skin

There are various causes for skin blisters. In this list we present you 13 origins, which turn out to be the most frequent.

1. Cold sores

Cold sores, also known as fever blisters or oral herpes, occurs after exposure to the herpes simplex virus type 1. This agent remains in the nerves indefinitely and various triggers (stress, fever or prolonged exposure to the sun) can cause its reactivation with the generation of the blister.

It usually starts with burning, tingling, tenderness in the lip or near the mouth. Blisters are usually very painful. When they are recurrent they tend to occupy the same place. There may be symptoms similar to those of the common cold, such as swollen lymph glands, muscle aches, and general malaise.

When the blisters drain the fluid, this can spread the virus to others through direct contact (kissing, oral sex) or contact with fomites (kitchen utensils, personal care items).

They heal spontaneously. However, fever blisters may take more than 2 weeks to heal. That is why topical antivirals are indicated.

2. Genital herpes

Genital herpes is a sexually transmitted infection caused by herpes simplex virus 1 and herpes simplex virus 2. It is one of the reasons for painful skin blisters. Before its appearance, the affected area behaves with burning, itching and tingling.

After the blisters break, they usually progress to painful ulcers. This liquid is capable of transmitting the virus by direct contact.

Herpes has no definitive treatment. It cannot be eradicated, but rather control and limit its acute attacks using antiviral drugs.

3. Scabies

In scabies, produced by the parasite Sarcoptes scabiei, there is an erythematous rash on the pathway caused by the entry of the parasite into the skin. There it leaves a small vesicle filled with fluid.

It is more common in the areas of the folds, where there is more moisture (wrists, between the fingers, in the armpits or around the waist). It is transmitted through prolonged skin-to-skin contact. Or through contaminated clothing.

4. Impetigo

Impetigo is the infection of the superficial layers of the skin by Streptococcus or Staphylococcous, two families of bacteria. The most common injuries are to the face or extremities.

It manifests as blisters that burst, leaving a honey-colored crust. Also, there is redness around the lesion and generalized itching.

Treatment is with oral antibiotics. Topically, to improve symptoms, creams with menthol or anesthetics such as pramoxine can be used.

5. Chickenpox

Chickenpox is one of the reasons for skin blisters caused by a viral infection. It is spread through coughing, sneezing, or contact with blisters.

There is a rash that is very itchy, with multiple blisters and vesicles of different sizes, which predominate on the trunk, face, and scalp. The blisters turn cloudy and burst, leaving a yellowish crust.

There is no specific treatment. In a few cases, oral antivirals are indicated.

6. Shingles or herpes zoster

This rash It is produced by reactivation of the chickenpox virus. The virus does not disappear from the body, but rather stays in a specific area of ​​the nerve cells.

That is why, when it is reactivated, the eruption that can occur years later follows the path of a nerve. This rash is very painful and presents with multiple blisters causing persistent and severe pain.

They are self-limited to 7-10 days, but in some cases oral antivirals are indicated. Pain from a nerve pathway or dermatome can linger for weeks, months, or years.

7. Pemphigoid

This is a disorder in which the immune system attacks the body, producing a skin rash predominantly on the extremities and abdomen. Being able to affect the mucous membranes.

It produces large, thick blisters filled with clear fluid or with a little blood. When they break they evolve to a lot of sensitivity and pain. There is no specific treatment.

8. Pemphigus vulgaris

Like the previous case, it is an autoimmune disease. But it differs in that the blisters itch and break more easily.

In addition, the content of the blisters is usually blood. When they are in the mouth and throat they cause a lot of pain.

9. Dyshidrotic eczema or pompholyx

In this case there is an erythematous (red) rash. Blisters appear predominantly on the hands and feetThey are large, red, painful and very itchy. When they break they usually leave dry and cracked scales.

The cause is unknown, but it is more common when there is a history of atopic dermatitis. There is no specific treatment, although symptoms usually improve with topical steroids.

10. Burns

In second-degree burns, blisters form that are very painful, large, and oozing, with red, or uneven-colored skin. They should always be evaluated by a doctor.

11. Freezing

Caused by extreme cold, these skin blisters are most common on the fingers and toes, nose, ears, cheeks, and chin. There is numb and cracked skin that is white and hard. Your skin may also turn black, lose feeling, or form blood-filled blisters.

12. Contact dermatitis

Contact dermatitis responds to an allergen. In this case, the rash has sharp edges and is consistent with where you came into contact with the irritant.

The skin becomes reddish, dry, and flaky. In addition, blisters appear that burst and dry, forming scabs.

There are different types of dermatitis. Blisters appear when the surface layer of the skin is shed by the allergic reaction.

13. By friction

In this case, the blisters are produced by the rubbing of the skin with an irritating surface for a prolonged period. It is more common in the hands and feet, especially when wearing tight shoes. Blisters form and heal spontaneously.



Are all the reasons for skin blisters serious?

Blisters are a defense mechanism of the skin to protect the damaged layer and help it heal, while keeping it isolated from the external environment. Although they can be very annoying, painful or uncomfortable, they are not usually a symptom of any serious underlying disease.

However, due to its multiple causes, there is no specific treatment. When in doubt, it is advisable to see a doctor.

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