Family Nurse Practitioner Exam

How is a bulla defined in dermatological terms?

1. A solid nodule less than 1 cm in size

2. A superficial vesicle filled with serous fluid greater than 1 cm in size

3. A maculopapular lesion

4. A shallow ulcer

The correct answer is: A superficial vesicle filled with serous fluid greater than 1 cm in size

In dermatological terminology, a bulla is defined specifically as a large blister that is filled with serous fluid and measures greater than 1 cm in size. This definition emphasizes the characteristics of a bulla, distinguishing it from smaller vesicles, which are defined as fluid-filled sacs that are less than 1 cm in size. This distinction is particularly important in clinical practice, as the size and contents of skin lesions can aid in diagnosis. For example, a bulla may arise from conditions such as burns, insect bites, or certain autoimmune diseases, indicating the presence of significant underlying pathology. In contrast, the other options describe different types of skin lesions and characteristics that do not align with the definition of a bulla. For instance, a solid nodule refers to a raised lesion that is typically less than 1 cm in size and does not contain fluid. A maculopapular lesion combines flat and raised components but does not specify any fluid content or size. Lastly, a shallow ulcer involves a loss of epidermis and possibly dermis, which is a different condition altogether compared to a bulla. Understanding these terminologies is crucial for accurate assessment and treatment in dermatological practice.