During an ear assessment, the nurse observes a bulging erythematous tympanic membrane with decreased mobility. What condition should the nurse suspect?

Rationale: A. Otitis externa, also called "swimmer’s ear," affects the external auditory canal. Common findings include ear pain, tenderness when the outer ear is manipulated, discharge, and canal edema. It does not typically cause a bulging tympanic membrane with decreased mobility, so this option is unlikely. B. Otitis media is an infection or inflammation of the middle ear. Classic signs include bulging, erythematous tympanic membrane, decreased mobility on pneumatic otoscopy, and sometimes fluid or pus behind the membrane. This combination of findings directly matches the nurse’s observation and is consistent with acute otitis media. C. Tympanic membrane perforation involves a rupture or hole in the eardrum. Assessment would reveal a visible opening or defect, sometimes with drainage, but not bulging or decreased mobility. Perforation usually relieves pressure rather than causing a tense, bulging appearance. D. Presbycusis is age-related hearing loss that affects high-frequency hearing over time. It does not cause visible changes in the tympanic membrane, such as bulging or erythema, and is not associated with decreased membrane mobility.