Bullae

Bullae are large blisters on the skin that are filled with clear fluid. Many different skin conditions can cause bullae to form. They can be caused by infection or inflammation of the skin.

Bullous pemphigoid - close-up of tense blisters

Pemphigus is classified as one of the blistering diseases. These is a close-up picture of typical lesions. Very small blisters are called vesicles. Larger blisters, like these, are called bullae.

Poison ivy on the knee

This is a typical early appearance of a poison ivy rash, located on the knee. These early lesions consist of multiple small blisters (vesicles), often in a line where the skin has brushed against the poison ivy plant. The person may then spread the toxin to other areas of the body by scratching.

Poison ivy on the leg

This is a typical early appearance of a poison ivy rash, located on the leg. These early lesions consist of multiple small blisters, often in a line where the skin has brushed against the poison ivy plant. The rash is caused by skin contact with the oily sap (resin) of these plants. The oily resin usually enters the skin rapidly, and is seldom transferred from person to person. The rash is not caused by the fluid from the blisters. Thus, once the person has washed the oil off the skin, the rash is usually not contagious.