What are bullae commonly described as?

Bullae are commonly described as fluid-filled blisters that are larger than vesicles, typically measuring more than 0.5 centimeters in diameter. These blisters can develop on the skin or mucous membranes due to various reasons, including friction, burns, or certain skin conditions like bullous pemphigoid. Their formation is characterized by the accumulation of serum or other fluids between the layers of the skin, leading to the characteristic swollen appearance. Recognizing bullae is important in clinical practice, as they can provide insights into underlying health issues or potential infections. Understanding their features helps in proper diagnosis and treatment.