Mastoiditis: Causes, Diagnosis, Treatment and Complications
Mastoiditis is infection and inflammation of the mastoid air-cell system in the temporal bone, usually occurring when acute otitis media spreads from the middle ear through the aditus into the mastoid antrum and air cells. It is uncommon in the antibiotic era, but it remains a potentially life-threatening ENT emergency because infection can erode bone and spread to the meninges, brain, venous sinuses, facial nerve or inner ear.
The clinical diagnosis depends on recognising a patient with recent or current middle-ear infection who develops post-auricular pain, erythema, tenderness or swelling, often with fever, otorrhoea and outward or downward displacement of the pinna. Suspected mastoiditis requires urgent hospital and ENT assessment; it is not an outpatient “wait-and-see” condition.
Tender swelling behind the ear is mastoiditis until proven otherwise. Give age-appropriate analgesia, begin the locally recommended first dose of parenteral antibiotic when indicated and feasible, and arrange urgent referral. Do not delay transfer while waiting for laboratory or imaging results.
Learning objectives
- Explain how middle-ear infection spreads into the mastoid air-cell system.
- Recognise uncomplicated, coalescent and complicated mastoiditis.
- Differentiate mastoiditis from otitis externa, lymphadenitis and superficial cellulitis.
- Select appropriate laboratory tests and imaging.
- Outline emergency medical and surgical management.
- Identify extracranial and intracranial complications early.
Relevant anatomy
The mastoid process lies behind the external auditory canal and contains multiple air cells lined by mucosa continuous with the middle ear. The mastoid antrum communicates with the epitympanum through the aditus. Review the structure of the external, middle and inner ear to understand the routes of spread.
Infection usually begins in the tympanic cavity and reaches the mastoid through the aditus. Oedema and pus can obstruct drainage and increase pressure.
Thin bony partitions separate the mastoid and middle ear from the inner ear, middle cranial fossa and posterior cranial fossa.
The sigmoid or lateral venous sinus lies close to the mastoid. Thrombophlebitis may cause persistent fever, headache, papilloedema or septic complications.
Pathogenesis
- Acute middle-ear infection: mucosal inflammation and pus involve both the middle ear and communicating mastoid air cells.
- Blocked drainage: oedema obstructs the aditus, trapping infected material within the mastoid.
- Pressure and osteitis: pus under pressure compromises mucosal blood flow and inflames the thin bony septa.
- Coalescence: bony septa are destroyed, converting separate air cells into an abscess cavity—coalescent mastoiditis.
- Extension: infection may break through the cortex to form a subperiosteal abscess or spread medially and intracranially.
Classification
| Type | Description | Clinical importance |
|---|---|---|
| Acute mastoiditis | Clinical inflammation of the mastoid associated with acute middle-ear infection. | Requires admission, intravenous antibiotics and urgent ENT review. |
| Incipient mastoiditis | Mucosal inflammation and retained fluid without radiological destruction of bony septa. | May respond to prompt medical treatment, but close observation is essential. |
| Coalescent mastoiditis | Osteitis with destruction of mastoid air-cell walls and formation of a larger infected cavity. | More likely to require drainage or cortical mastoidectomy. |
| Subperiosteal abscess | Infection has breached the mastoid cortex and collected beneath the periosteum. | Fluctuant post-auricular swelling; drainage plus treatment of the middle ear or mastoid is usually required. |
| Chronic mastoid disease | Persistent mastoid inflammation associated with chronic suppurative otitis media or cholesteatoma. | Needs ENT assessment and frequently definitive surgery; management differs from simple acute disease. |
Causes and risk factors
Mastoiditis most often follows bacterial acute otitis media. Common pathogens include Streptococcus pneumoniae, Streptococcus pyogenes, non-typeable Haemophilus influenzae and Staphylococcus aureus. Organisms may differ after previous antibiotics, with chronic ear disease, after ear surgery or in immunocompromised patients. Pseudomonas aeruginosa is particularly relevant in chronic suppurative disease and when previously isolated; culture results and the local antibiogram should guide definitive therapy.
Predisposing factors
- Recent, severe, recurrent or inadequately treated acute otitis media.
- Young age, especially infancy and early childhood.
- Persistent tympanic-membrane perforation, chronic suppurative otitis media or cholesteatoma.
- Previous ear surgery, ventilation tube or congenital ear abnormality.
- Incomplete pneumococcal or Haemophilus influenzae type b immunisation.
- HIV infection, diabetes, immunosuppression or severe malnutrition.
- Craniofacial anomaly or Eustachian-tube dysfunction.
Clinical presentation
History
- Recent or current ear pain, fever, irritability, reduced feeding or sleep disturbance.
- Ear discharge, which may follow tympanic-membrane perforation.
- Pain or tenderness behind the ear and progressive post-auricular swelling.
- Reduced hearing, blocked-ear sensation or tinnitus.
- Failure to improve or deterioration despite treatment for acute otitis media.
- Recurrent ear infection, chronic discharge, previous surgery or antibiotic exposure.
Examination findings
- Fever, tachycardia, irritability or other signs of systemic illness.
- Post-auricular erythema, oedema and marked tenderness over the mastoid.
- Loss or obliteration of the post-auricular sulcus.
- The pinna may be pushed outward and downward; in very young children it may project more horizontally because the mastoid tip is not fully developed.
- Fluctuance suggests a subperiosteal abscess.
- Otoscopic signs of acute otitis media: a bulging, opaque or perforated tympanic membrane, middle-ear pus or otorrhoea.
- Posterior-superior canal-wall sagging may occur as inflammation spreads from the mastoid.
- Conductive hearing loss is common; sensorineural loss suggests inner-ear involvement.
Severe or persistent headache, vomiting, neck stiffness, photophobia, altered consciousness, seizures, focal neurological signs, facial weakness, diplopia, vertigo, nystagmus, papilloedema, toxic appearance or persistent fever despite treatment may indicate intracranial, venous-sinus, facial-nerve or labyrinthine spread.
Assessment and investigations
Mastoiditis is primarily a clinical diagnosis. Investigations assess severity, identify the organism and detect complications; they must not delay antibiotics, resuscitation or ENT referral in an unwell patient. Use clean, appropriate basic ENT instruments and examine both ears.
Immediate clinical assessment
- Assess airway, breathing, circulation, hydration, consciousness and age-specific danger signs.
- Record temperature and vital signs; screen for sepsis.
- Inspect and palpate the pinna, mastoid and surrounding scalp and neck.
- Perform otoscopy without force. If discharge blocks the view, experienced staff may undertake gentle aural toilet under direct vision.
- Document facial movement, eye movements, hearing, balance, gait, meningeal signs and a focused neurological examination.
- Look for cholesteatoma, granulation tissue, a post-auricular sinus or features of chronic ear disease.
Investigations and interpretation
| Investigation | Why it is ordered | Interpretation and cautions |
|---|---|---|
| Full blood count | Assesses leukocytosis, anaemia and baseline status. | A normal count does not exclude mastoiditis, especially after antibiotics or in immunocompromise. |
| CRP and/or ESR | Provides a baseline inflammatory marker and can help monitor response. | Non-specific; trend with the clinical condition rather than treating a number alone. |
| Blood culture | Useful before antibiotics in a febrile, toxic or septic patient. | Do not delay urgent antibiotics if obtaining culture is difficult. |
| Ear-discharge culture | Helps identify the pathogen when spontaneous otorrhoea is present. | Collect a deep specimen after gentle canal cleaning; a superficial swab may reflect canal colonisers. Review ENT swab collection and handling. |
| Middle-ear or abscess specimen | Obtained during myringotomy, tube placement or drainage. | Usually provides a better specimen for microscopy, culture and sensitivity than a superficial canal swab. |
| CT temporal bones | Defines bony erosion, coalescence, cortical breach and abscess; often extended with contrast when complications are suspected. | Mastoid opacification alone is non-specific and can occur in uncomplicated otitis media. Correlate with clinical signs and look specifically for loss of bony septa or an abscess. |
| Contrast MRI brain/temporal region | Better assesses meninges, brain, labyrinth, dura and venous sinuses when intracranial spread or sinus thrombosis is suspected. | MRI complements rather than replaces CT when fine bony anatomy and surgical planning are important. |
| Hearing assessment | Documents conductive or sensorineural loss after the acute phase. | Formal audiometry is usually arranged once pain, discharge and swelling have settled. |
| Targeted tests | Renal/liver function, glucose, HIV testing or lumbar puncture according to presentation. | Lumbar puncture is not routine and must be deferred when raised intracranial pressure, focal signs or a mass lesion are suspected. |
See the companion guide to ordering and interpreting ENT investigations. Imaging decisions should be made with ENT and radiology, particularly in children and when advanced imaging is limited.
Differential diagnosis
| Condition | Clues | How it differs from mastoiditis |
|---|---|---|
| Otitis externa | Tragal or pinna-movement tenderness, swollen ear canal and canal discharge. | Post-auricular inflammation and protrusion of the pinna are not typical; the tympanic membrane may be normal if visible. |
| Post-auricular cellulitis | Superficial skin infection, wound, insect bite or infected piercing. | No convincing acute otitis media or mastoid tenderness; imaging may be needed when uncertain. |
| Posterior auricular lymphadenitis | Discrete tender lymph node with scalp, skin or upper-respiratory infection. | Localised node rather than diffuse mastoid swelling; ear position and otoscopy may be normal. |
| Parotitis | Pre-auricular or angle-of-jaw swelling, pain with chewing and possible duct discharge. | Swelling is centred anterior and inferior to the ear rather than directly over the mastoid. |
| Infected sebaceous cyst or abscess | Superficial fluctuant lesion, punctum or skin origin. | No middle-ear infection or deep mastoid tenderness. |
| Temporal-bone tumour or Langerhans-cell histiocytosis | Atypical prolonged symptoms, mass, facial palsy, bleeding or poor response to antibiotics. | Requires imaging, specialist review and often biopsy. |
Emergency management
At primary-care or first-contact level
- Recognise and stabilise: assess ABC, sepsis, hydration, neurological status and severe pain.
- Treat immediate needs: give weight-appropriate paracetamol or ibuprofen when safe; correct hypoglycaemia, dehydration or shock according to protocol.
- Start urgent treatment: if local emergency guidance directs and referral will not be delayed, give the first dose of an appropriate parenteral antibiotic.
- Refer urgently: contact the receiving hospital or ENT team and arrange safe transfer.
- Document: onset, antibiotics already given, allergies, vital signs, neurological findings and referral communication.
Uganda’s IMCI guidance classifies tender swelling behind the ear as mastoiditis and directs a first dose of an appropriate antibiotic, pain relief and urgent hospital referral. The exact drug and dose must follow the current Uganda Clinical Guidelines, age/weight, allergy status, renal function and local resistance data.
Hospital treatment
Empirical therapy should cover common acute otitis media pathogens. A third-generation cephalosporin is commonly used; broaden for MRSA, chronic suppurative disease, previous Pseudomonas, immunocompromise or intracranial spread according to specialist advice and the local antibiogram.
Myringotomy with aspiration or tympanostomy-tube insertion drains the middle ear and provides culture material. A subperiosteal abscess usually needs drainage.
Cortical mastoidectomy may be required for coalescent disease, abscess, cholesteatoma, intracranial complication or failure to improve with adequate antibiotics and drainage.
Monitoring response
- Review fever, pain, post-auricular swelling, pinna position, otoscopy and neurological status frequently.
- Monitor hydration, urine output, inflammatory markers and antimicrobial toxicity as appropriate.
- Reassess the diagnosis, imaging and need for surgery if there is clinical deterioration or inadequate improvement within 24–48 hours.
- Tailor therapy to culture results. Duration and switch from intravenous to oral therapy depend on clinical response, source control, organism and complications; specialist regimens commonly total about 7–14 days for uncomplicated acute mastoiditis and longer for bone, venous-sinus or intracranial disease.
This page teaches management principles and is not a prescription. Drug selection and dosing must be checked against the current Uganda Clinical Guidelines and hospital protocol. Consider age, weight, pregnancy, allergy, renal/hepatic function, previous cultures and local resistance patterns.
Surgical procedures
Myringotomy and tympanostomy tube
A small incision in the tympanic membrane allows middle-ear pus to drain. A ventilation tube may be inserted to maintain drainage. Aspirated material should be sent for microscopy, culture and sensitivity. This procedure does not treat a large subperiosteal or intracranial collection by itself.
Incision and drainage
A fluctuant subperiosteal abscess is drained by the ENT team, usually together with middle-ear drainage and assessment of the mastoid. Needle aspiration may have a role in selected cases under specialist care, but repeated superficial aspiration must not substitute for adequate source control.
Cortical mastoidectomy
In cortical mastoidectomy, diseased mastoid air cells are opened and removed to drain infection and restore communication with the middle ear. Indications include coalescent mastoiditis, persistent or recurrent abscess, cholesteatoma, neurological or intracranial complication, and failure of appropriate medical treatment.
Complications
Extracranial and intratemporal complications
- Subperiosteal abscess: a fluctuant post-auricular collection with marked pinna displacement.
- Bezold abscess: pus tracks through the medial mastoid tip into the upper neck, causing painful neck swelling or torticollis.
- Zygomatic abscess: infection tracks into the zygomatic root and temporal region.
- Facial-nerve palsy: weakness of the ipsilateral face due to inflammation or bony dehiscence.
- Labyrinthitis: vertigo, nystagmus, vomiting and sensorineural hearing loss.
- Petrositis: infection of the petrous apex; Gradenigo syndrome classically combines persistent ear discharge, deep facial or retro-orbital pain and sixth-nerve palsy.
- Permanent hearing loss: conductive loss from middle-ear damage or sensorineural loss from inner-ear involvement.
Intracranial complications
- Meningitis.
- Epidural abscess.
- Subdural empyema.
- Temporal-lobe or cerebellar brain abscess.
- Sigmoid or lateral venous-sinus thrombosis.
- Raised intracranial pressure, hydrocephalus, seizures and neurological disability.
Intracranial spread can occur even when local ear findings appear modest. Persistent headache, vomiting, drowsiness, focal deficit, seizure, diplopia or papilloedema demands urgent imaging and coordinated ENT, paediatric/medical, radiology, microbiology and neurosurgical care.
Nursing care and patient education
- Record vital signs, pain score, consciousness, fluid balance and neurological observations.
- Administer prescribed antibiotics and analgesics on time; check allergies and monitor adverse effects.
- Keep the affected ear dry and avoid inserting cotton buds, herbal preparations, oil or unprescribed drops.
- Use sterile technique for dressings and postoperative wound care.
- Explain why improvement in pain does not justify stopping antibiotics early.
- Teach caregivers to return immediately for increasing swelling, fever, severe headache, vomiting, imbalance, facial weakness, drowsiness or seizure.
- Arrange completion of treatment, ENT review, wound review and hearing assessment.
Prevention
- Recognise and appropriately manage acute and chronic middle-ear infection.
- Ensure age-appropriate pneumococcal, Haemophilus influenzae type b, influenza and measles immunisation according to the national schedule.
- Reduce tobacco-smoke and indoor-air-pollution exposure.
- Promote breastfeeding and good nutrition.
- Follow up persistent ear discharge, recurrent AOM, hearing loss and suspected cholesteatoma.
- Encourage early review when an ear infection worsens or fails to improve.
Clinical scenario
A 3-year-old child treated for ear pain four days earlier now has fever, purulent left-ear discharge and painful swelling behind the ear. The post-auricular sulcus is lost and the pinna is displaced outward. The child is irritable but alert, with no neck stiffness or focal neurological sign.
Interpretation: the history and examination strongly suggest acute mastoiditis, possibly with a developing subperiosteal collection. Assess ABC and sepsis, provide analgesia, start protocol-directed parenteral antibiotic treatment without delaying transfer, and refer urgently to hospital/ENT. Obtain cultures and blood tests in hospital and decide on imaging and drainage with the specialist team. Recheck repeatedly for neurological or vestibular red flags.
Key examination points
- Mastoiditis is usually a complication of acute otitis media.
- The most important signs are post-auricular tenderness, erythema or swelling, loss of the sulcus and protrusion of the pinna.
- A tender swelling behind the ear in a child requires urgent hospital referral.
- Mastoid opacification on CT alone does not prove coalescent mastoiditis; correlate with the clinical picture and bony erosion.
- Initial treatment is hospital admission, intravenous antibiotics, analgesia and urgent ENT assessment.
- Myringotomy, abscess drainage or mastoidectomy provides source control when indicated.
- Always look for facial palsy, labyrinthitis, meningitis, brain abscess and venous-sinus thrombosis.
References and further reading
- Uganda Ministry of Health: Integrated Management of Childhood Illness chart booklet.
- Royal Children’s Hospital Melbourne: Acute otitis media clinical practice guideline.
- NICE NG91: Otitis media (acute)—antimicrobial prescribing.
- NHS: Mastoiditis—symptoms, diagnosis and treatment.
- NHS Scotland Right Decisions: Acute mastoiditis hospital guidance.
- World Health Organization: Chronic suppurative otitis media.
For education only. In suspected mastoiditis, follow current national and local protocols and obtain urgent senior ENT or hospital advice.
