Vesicles are small, fluid-filled sacs that can appear on your skin. The fluid inside these vesicles may be clear, white, yellow, or mixed with blood. These sacs may be very small, or they may be over an inch in diameter. Vesicles are also known as blisters or bulla.
Vesicles develop when fluid becomes trapped under the top layer of your skin, called the epidermis. A number of different health conditions can cause vesicles. Some of these conditions are minor and will not require you to seek medical attention. Others are more serious and can signal a complicated medical issue that needs on-going treatment.
Minor causes of vesicles include:
- allergic reactions to substances, causing irritation of the skin
- dermatitis, or eczema
- contact dermatitis, such as when you come in contact with poison ivy or poison oak
- cold sores
You will need to see a doctor if your vesicles are a result of:
- autoimmune disorders, such bullous pemphigoid
- chicken pox or shingles
- skin diseases that cause blistering, such as porphyria cutanea tarda
- impetigo, a skin condition caused by infection with strep or staph bacteria
Often, vesicles are easy to recognize. Most develop on the surface of the skin and cause the skin to swell with fluid. The skin around the vesicle keeps the fluid contained.
Most vesicles rupture easily. When this happens, the fluid inside will be released onto the skin. When the fluid dries, it may turn yellow or crusty.
You should always make an appointment with your doctor if you develop unexplained vesicles on your skin. During the visit, your doctor will ask you about your recent health history and any medical conditions you have that might be causing the vesicles.
He or she will also examine your skin. Your doctor may able to diagnose the cause of your vesicles based on this information alone.
If your doctor is uncertain about what is causing your vesicles, he or she may recommend that you have more tests. He or she may 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 confirm your diagnosis.
Treatment for your vesicles depends on the cause. Over-the-counter remedies may be enough to treat vesicles caused by allergic reaction, dermatitis, poison ivy, or cold sores.
However, you will need to see a doctor if your vesicles are caused by a more serious health problem or if you do not know what is causing your vesicles.
In some cases, your vesicles will be accompanied by other serious symptoms, such as inflammation or infection. Your doctor may then prescribe medications. For example, bullous pemphigoid—a type of autoimmune disorder that affects the elderly—is typically treated with corticosteroids to help reduce inflammation and antibiotics to help prevent infection.
Always talk with your doctor about the best treatment options to reduce your symptoms.
Your outlook will depend 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 they may reoccur throughout your life. Proper treatment may be able to relieve your symptoms. However, if you have one of these chronic conditions, the vesicles are likely to return.
In some instances, it may not be possible to prevent vesicles. If you know you have allergies, you can help prevent the development of vesicles by avoiding your allergens. You should also take care not to share cups, straws, or lip products.