Hearing loss - red flag symptoms

By Dr Kamilla Porter on the 5 August 2019

Dr Kamilla Porter highlights red flag symptoms associated with hearing loss in adults, and discusses when urgent referral is needed.

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Red flag symptoms

Sudden onset
Unilateral sensorineural hearing loss
Associated facial droop or altered sensations
Associated otalgia and otorrhoea in the immunocompromised
Persisting middle ear effusion in patients of Chinese or Southeast Asian origin

Presentation

Hearing loss is a common presentation in primary care and a systematic approach to assessment is required to detect red flag symptoms.

In the first instance, after taking a preliminary history, it is reasonable to move on to examination to exclude ear wax or an acute infection such as otitis externa. If there is no significant wax or obvious infection a more detailed history and examination are required.

The history should be guided according to the patient’s age and risk factors, but it is essential to establish whether onset of hearing loss is acute or more gradual, as well as whether one or both ears are affected.

Enquire about associated symptoms such as vertigo, tinnitus or any other neurological symptoms and take a detailed drug history noting use of any ototoxic medication (see below). It is also important to determine whether there is a significant family history of deafness.

Tests to categorise causes of hearing loss

Weber's test
A tuning fork (512 Hz) is struck and applied to the forehead and the patient is asked in which ear they hear the sound louder. In conductive deafness the patient will hear the sound louder in the affected ear. If the sound is heard in the unaffected ear there is sensorineural loss.

Rinne's test
The vibrating tuning fork is held in front of the external auditory meatus (measuring air conduction) and then the base of the fork is placed on the mastoid process until the patient indicates it can no longer be heard (measuring bone conduction). The patient is then asked which is the loudest.

Interpretation of tests

Rinne's test is positive when air conduction is greater than bone conduction and negative when bone conduction is greater than air conduction.

If Weber's test lateralises to the left and Rinne's test is negative on the left, this indicates conductive hearing loss in the left ear.

If Weber's test lateralises to the left and Rinne's test is positive on the left, this indicates sensorineural loss in the right ear

Causes of hearing loss

Conductive hearing loss may be caused by the following:

Ear wax
Foreign body in ear canal
Otitis externa
Otitis media
Otosclerosis
Postnasal space tumour

Causes of sensorineural hearing loss include the following:

Presbyacusis (age-related hearing loss)
Noise damage
Ménière’s disease
Acoustic neuroma
Barotrauma
Drug-induced hearing loss
Multiple sclerosis
Vascular event
Idiopathic hearing loss

Some drugs, including those listed below, have the potential to cause hearing impairment and tinnitus. The drugs listed below link to their entry on MIMS.

Chemotherapy
Cisplatin, actinomycin - D, bleomycin, carboplatin, vincristine, oxaliplatin

Antibiotics
Gentamicin, erythromycin, tobramycin, amikacin, neomycin, vancomycin, capreomycin

Loop diuretics
Furosemide, acetazolamide, bumetanide

Antimalarials
Chloroquine hydroxychloroquine, quinine sulfate, mefloquine

NSAIDs
Naproxen, aspirin, diclofenac, ibuprofen, indometacin

Referral

In patients with sudden onset or rapid worsening of hearing loss (either unilateral or bilateral), and in the absence of obvious external or middle ear causes, NICE recommendations are to refer to ENT in the following situations.

Sudden hearing loss that has developed over a period of 72 hours or less within the past 30 days for immediate (same day) assessment
Sudden hearing loss with an onset over 30 days ago should be seen within two weeks
Rapid worsening of hearing loss should be seen within two weeks

Cases of idiopathic sudden sensorineural hearing loss (ISSHL) are commonly treated by ENT specialists with oral steroids. However, the specific action of steroids is not well understood.

Immediate ENT referral is also indicated in cases of new unilateral hearing loss associated with a facial droop or altered sensation on the same side, or to the stoke service if a vascular event is suspected.

Immuno-compromised patients with persisting otalgia with otorrhoea, who have failed to respond to treatment also require same-day assessment.

Cases of unilateral progressive sensorineural deafness, especially if associated with tinnitus or vertigo, need to be referred to exclude an acoustic neuroma.

Post-nasal space tumours can present with persistent and unexplained conductive hearing loss and may be accompanied by nasal obstruction and epistaxis. The incidence of this malignancy is particularly high in those of Southeast Asian origin.

Hearing impairment associated with otitis media will resolve within a few weeks in most cases. It is important to convey this to the patient and explain that further antibiotics are seldom required. However, if hearing impairment persists, referral is necessary to exclude a post-nasal space tumour.

Otosclerosis usually causes bilateral conductive hearing loss and is typically due to fixation of the stapes. It is usually present in young adults with a family history, and it is important to refer for early diagnosis and treatment. There may be associated tinnitus and positional vertigo and the tympanic membrane is often normal on examination.