Bulla

• Fluid-filled blister greater than 1 cm in diameter.
• Fluid can be clear, serous, hemorrhagic, or pus filled.
• Bullae are characterized as tense or flaccid.

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  Round flaccid bullae and patches of fixed drug eruption.

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  Tense serous bullae in pemphigoid gestationis.

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  Tense bullae of allergic contact dermatitis at a finger web space.

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  Small flaccid bulla with surrounding erythema in disseminated gonorrhea.