Final answer:
A bulla is indeed a large blister, specifically referring to fluid-filled lesions that are at least 5 mm in diameter, commonly associated with skin conditions like bullous impetigo. This statement is true.
Step-by-step explanation:
The statement "A bulla is a large blister" is true. A bulla is indeed a large, fluid-filled blister that measures at least 5 mm in diameter. In the context of skin infections like impetigo, bullae may form, and, in the case of bullous impetigo, these bullae fill and rupture, which can result in larger, draining, encrusted lesions on the skin, especially around areas like the nose and mouth.