Vesicles are small, fluid-filled sacs that can appear on your skin. The fluid inside these sacs may be clear, white, yellow, or mixed with blood.

Vesicles are also sometimes referred to as blisters or bullae, though there are slight size differences among the three. Vesicles are typically about 5 to 10 millimeters in diameter. If the sacs become larger than that, they’re classified as blisters. If they have a diameter of at least half a centimeter, they’re known as bullae.

Vesicles develop when fluid becomes trapped under the epidermis, the top layer of your skin. A number of different health conditions can cause them. Some of these conditions are minor and don’t require medical attention. Others are more serious and can signal a complicated medical issue that needs ongoing treatment.

Minor causes of vesicles include:

You should see a doctor if your vesicles are a result of:

Vesicles are often easy to recognize. Most develop on the surface of the skin and cause it to swell with fluid. The skin around a vesicle keeps the fluid contained.

Vesicles tend to rupture easily and release their fluid onto the skin. When the fluid dries, it may turn yellow or crusty.

Conditions that produce symptoms similar to vesicles can include:

When a rash appears in the same place as multiple vesicles, it’s known as a vesicular rash. Heat rashes are one type of vesicular rash, occurring mainly in folds of the skin or wherever clothing can cause friction. Infections, such as staph infections that have spread, can also cause vesicular rashes. Contact dermatitis is an extremely common cause of vesicular rash.

Vesicular rashes may spread quickly. In the case of bacterial infections, keep the rash clean to prevent it from spreading to other parts of the body.

You should always make an appointment with your doctor if you develop unexplained vesicles on your skin. During the visit, they’ll ask you about your recent health history and about any medical conditions that might be related to the vesicles.

They’ll also examine your skin. Your doctor may be able to diagnose the cause of your vesicles based on this information alone.

If your doctor is uncertain about a diagnosis, they may recommend more tests. They may also take a sample of fluid or a biopsy of the skin tissue from the vesicle to send to a lab. The analysis of the sample will help them to confirm a diagnosis.

You should always talk with your doctor about the best treatment options to reduce your symptoms.

Treatment for your vesicles depends on the cause. Over-the-counter (OTC) remedies may be enough to treat vesicles resulting from allergic reaction, dermatitis, poison ivy, or cold sores. Many of these remedies are topical ointments that can soothe the skin. Antihistamines may be able to reduce allergy-related symptoms.

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Vesicles can be accompanied by other serious symptoms, such as inflammation or infection. In these cases, your doctor may prescribe medications to treat the underlying causes.

For example, bullous pemphigoid — a type of autoimmune disorder that affects older adults — is typically treated with corticosteroids to help reduce inflammation and antibiotics to help prevent infection.

Bacterial infections are typically treated with oral antibiotics so as not to aggravate the vesicles.

Vesicles caused by eczema are often treated with topical medications, including retinoids and glucocorticoids.

Burn blisters or vesicles will be treated with prescription burn creams. You may also be prescribed oral antibiotics to reduce the chance of infection.

Home treatments including alternative remedies can often be effective for treating vesicles or blisters.

To care for an open or torn vesicle, wash the area with soap and water. You can use OTC antibiotic ointment to prevent infection. Cover the area with a clean bandage to protect it.

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Natural treatments for vesicles that haven’t been torn or drained include:

  • aloe vera, which is soothing and has anti-inflammatory properties
  • apple cider vinegar, which has anti-inflammatory and antibacterial properties to reduce swelling and help dry the vesicle out
  • tea tree oil, which has antibacterial and astringent properties

Amazon has a selection of aloe vera, apple cider vinegar, and tea tree oil products for purchase.

Popping a vesicle isn’t typically advised. This can leave the area open to infection and make it take longer to heal. Unless the vesicle becomes large and exceptionally painful, leaving it alone is best.

Your outlook depends on the underlying cause. If your vesicles are caused by an allergic reaction or contact dermatitis, you will typically make a full recovery after treatment.

More serious cases of vesicles can be a result of your genetics or an infection with a virus, so the vesicles may reoccur throughout your life. Proper treatment may relieve your symptoms. However, if you have a chronic condition, the vesicles are likely to return.

If you know you have allergies, you can help prevent vesicles by avoiding allergy triggers. You should also take care not to share cups, straws, or lip products.

Try not to wear tight-fitting clothing that rubs uncomfortably on the skin, especially in hot or damp weather. You should wear proper attire for sports or physical activity, such as socks with extra padding. Moisture-wicking clothing can also be helpful.

Keep your skin clean, maintain good hygiene, and avoid irritants that could aggravate your skin. Antibacterial soaps can help prevent vesicles from becoming infected (and infections from causing vesicles). Shower immediately after working out or coming into contact with a potential skin irritant.

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In some instances, it may not be possible to prevent vesicles.

Most vesicles, blisters, and bullae can be treated with OTC treatments and home remedies. In some cases, however, it’s a good idea to call your doctor.

See your doctor if…

  • you’re experiencing signs of an infection, including swelling, increased redness, streaks from the vesicle, and warmth at the site of the vesicle
  • you’re getting vesicles or blisters often or have a large number of blisters and don’t know why
  • you have a band of painful vesicles on one side of your body or face, which could indicate shingles
  • you have diabetes and get vesicles or blisters on your hands, feet, or legs

If you experience a rapid spread of vesicles, especially with a rash, and symptoms such as shortness of breath, pain, or dizziness, you may be having an allergic reaction to medications. In these cases, you should seek immediate medical attention.

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