What Is a Bulla?
A bulla is a large, fluid-filled blister that forms beneath the outer layer of the skin. Unlike a smaller blister (vesicle), a bulla is typically larger than 0.5 centimeters (about one-fifth of an inch) in diameter. Bullae can develop because of burns, friction, infections, allergic reactions, or certain skin conditions.
Most bullae protect the underlying skin while it heals and should not be intentionally punctured unless instructed by a healthcare provider.
Why Bullae Matter
A bulla protects damaged skin from further injury and infection. However, if it becomes infected, ruptures prematurely, or results from an underlying medical condition, medical evaluation may be necessary.
Common Causes of Bullae
- Burns
- Friction from shoes or repetitive movement
- Bullous skin disorders
- Allergic reactions
- Certain infections
- Diabetes-related skin conditions
- Exposure to chemicals
Common Symptoms
- Large fluid-filled blister
- Clear or yellowish fluid inside the blister
- Redness around the affected area
- Pain or tenderness
- Swelling
- Skin irritation
How Is a Bulla Treated?
Treatment depends on the cause and may include protecting the blister with a sterile dressing, treating the underlying condition, preventing infection, and providing wound care if the blister breaks.
How Home Care Can Help
Home care professionals monitor the affected skin, perform wound care according to the healthcare provider’s instructions, watch for signs of infection, encourage proper hygiene, and help protect the area from further injury.
Home Care Tip
Avoid popping a bulla unless your healthcare provider instructs you to do so, as the intact skin helps protect against infection.
Frequently Asked Questions About Bullae
What is the difference between a blister and a bulla?
A bulla is simply a larger blister. Bullae measure more than 0.5 centimeters in diameter, while smaller fluid-filled blisters are called vesicles.
Can a bulla become infected?
Yes. If the skin breaks, bacteria can enter the wound and cause an infection, making proper wound care important.
Can home care professionals help care for a bulla?
Yes. Home care professionals provide wound care, monitor healing, watch for infection, and help individuals protect the affected area during recovery.
When to Contact Your Healthcare Provider
Contact your healthcare provider if a bulla becomes increasingly painful, develops redness or pus, is accompanied by fever, or if multiple unexplained bullae appear.