What are the key clinical features that suggest a diagnosis of otosclerosis in a patient presenting with hearing loss?

Key clinical features suggesting otosclerosis in a patient with hearing loss include:

• Progressive conductive hearing loss, typically bilateral but may be asymmetric, often presenting in early to middle adulthood.
• Normal tympanic membrane and middle ear appearance on otoscopy, as otosclerosis affects the stapes footplate rather than causing middle ear effusion or infection.
• Absent or reduced acoustic reflexes due to stapes fixation.
• Carhart’s notch on audiometry, a specific dip in bone conduction thresholds around 2 kHz, is characteristic.
• Family history may be positive, as otosclerosis has a genetic predisposition.
• Absence of middle ear inflammation or effusion (a “dry middle ear cleft”) helps differentiate otosclerosis from other causes of conductive hearing loss such as otitis media with effusion.
• CT imaging

These features combined support a clinical diagnosis of otosclerosis in adults presenting with conductive hearing loss, guiding further audiological assessment and management NICE CKS Nguyen et al. 2019 Motta et al. 2024.