Acute Care Nurse Practitioner Certification 2025 Practice Exam – The All-in-One Guide for Guaranteed Success!

A bulla is a large fluid-filled blister that can form on the skin or mucous membranes, typically exceeding 0.5 centimeters in diameter. Understanding this classification requires an appreciation of the types of skin lesions commonly encountered in clinical practice.

Contact dermatitis is a skin inflammation that occurs when the skin comes into contact with an irritant or allergen. One of the possible manifestations of contact dermatitis can include the development of bullae. These lesions result from the accumulation of fluid between layers of the skin, often prompting a blister-like appearance that can be quite large.

In contrast, a sebaceous cyst is a closed sac under the skin filled with a mixture of skin oils and debris, which does not present itself as a blister but rather as a lump. While both hives (urticaria) and pustules (which are small bumps on the skin containing pus) can also occur in inflammatory processes, they do not fit the definition of a bulla, as they are characteristically different in structure and size.

Recognizing the nature of contact dermatitis and its potential to lead to the formation of bullae provides essential context for understanding larger skin lesions that can arise from various inflammatory conditions.