How not to miss Mastoiditis
This new series focuses on rare but serious conditions where accurate diagnosis and rapid treatment are essential but which often masquerade as something common and minor. To kick off, Dr John Hart spotlights mastoiditis and defines the key elements that will allow GPs to diagnose this condition confidently
Worst outcomes if missed
(although all are extremely rare nowadays, they are potentially serious due to the proximity of the mastoid and middle ear to important structures).
Up to 6.8 per cent of acute mastoiditis patients develop intracranial complications. The mortality rate in this situation is high, ranging from 14-36 per cent.
·Petrositis (infection in the petrous temporal bone) Gradenigo's Triad (subacute otitis media, retro-orbital pain and abducens nerve palsy)
·Meningitis (~0.85 per cent)
·Extradural abscess (~1.7 per cent)
·Sigmoid sinus thrombosis (~2.6 per cent)
·Lateral sinus thrombosis
·Mastoid emissary vein thrombosis
·Facial nerve palsy (~0.005 per cent of otitis media in children)
·Carotid artery arteritis
·Bezold's abscess (pus tracks along digastric muscles toward chin or along sternocleidomastoid muscle)
Epidemiology and incidence
·Mastoiditis is usually a complication of otitis media
·Occurs in countries with high antibiotic use (eg US) 1.2 - 2 / 100,000
·Occurs in countries with low antibiotic use (eg Netherlands) 3.8 / 100,000
·Peak age: children (reflecting level of underlying incidence of otitis media)
·Male and female equal
·Pain (98 per cent) either localised or general diffuse headache
·Fever (83 per cent)
·Inflamed tympanic membrane (88 per cent) as complication of acute otitis media
·Post-auricularoedema(76percent), swelling and erythema
·Fluctuant swelling behind ear
·Displacement of external ear down and outwards (best viewed from behind)
·Discharge from ear
·Tender over mastoid antrum (MacEwen's Triangle) or over mastoid tip
·External auditory canal narrowed due to sagging of posterior-superior meatal wall
·Oedema upper eye lid (from spread
beneath temporal fascia from root of zygoma)
·May look like furuncle on posterior canal wall
·Diplopia (Gradenigo's Triad involving abducens nerve)
·Abscess along digastric below chin or down sternocleidomastoid (Bezold)
Mastoiditis is primarily a clinical diagnosis and may be the first presentation of any ear disease.
·Trauma to mastoid or ear
·Pyrexia of unknown origin/sepsis
·Furuncle in posterior canal wall
See the boxes above right for five key questions to ask and five red herrings.
If you suspect mastoiditis admit immediately. Little benefit in investigation by GP.
·FBC with raised WCC, ESR, CRP
·M,C & S of any discharge from ear
Secondary care: as above and in addition:
·CT scan of mastoids
·MRI particularly if suspect intracranial or extracranial complications
·Lumbar puncture if suspect meningitis
John Hart is a GP in Kettering, Northamptonshire, and a clinical assistant in ENT at Kettering General Hospital
Competing interests None declared
Next week: Myeloma
Five key questions to ask
1 Have you had a recent ear infection?
(Most cases are related to an episode of
2 Have you been on antibiotics within the last few weeks? (Signs and symptoms of mastoidit
is may be much more subtle)
3 If you have been on antibiotics, what were they called and how long did you take them for and did you miss any doses? (Mastoiditis more likely to develop if inappropriate or course is
too short or taken incorrectly)
4 If you had antibiotics, do you still have pain and a raised temperature?
(Mastoiditis, abscess or complications need to be considered if symptoms of pain and fever persist in spite of good antibiotic treatment)
5 Are you suffering from....double vision, headache, vomiting, dizziness, weakness of your face (looking for intra- and extra-cranial complications)?
Five red herrings
1 Antibiotics modify or mask the typical signs making them much more subtle
2 Masked mastoiditis complications may only be evident from neurological examination
3 If otitis media pain and fever persist in spite of antibiotics, consider mastoiditis
4 May have an underlying ear disease such as cholesteatoma
5 Tenderness over mastoid may be tender post-auricular lymph nodes (reactive