From the Guidelines
Mastoiditis is an infection of the mastoid bone behind the ear, typically occurring as a complication of untreated or severe middle ear infections, and its diagnosis involves a thorough physical examination, otoscopic examination, and diagnostic tests such as cultures, complete blood count, and imaging studies like CT scans and MRI. The key signs and symptoms of mastoiditis include:
- Persistent ear pain
- Redness and swelling behind the ear
- Ear drainage
- Fever
- Headache
- Hearing loss The affected area often appears red, tender to touch, and the ear may protrude outward due to inflammation. In severe cases, patients may experience systemic symptoms like irritability, lethargy, and neck stiffness. According to 1, several case series show that 33% to 81% of patients diagnosed with mastoiditis had been treated with antibiotics prior to admission, suggesting that antibiotics administered for acute otitis media (AOM) treatment do not eliminate the risk of developing this complication. The diagnosis of mastoiditis involves a thorough physical examination where the doctor inspects the ear and mastoid region, looking for characteristic signs of infection and inflammation. Otoscopic examination typically reveals a bulging, red tympanic membrane or perforation with purulent discharge. Diagnostic tests include:
- Cultures of ear drainage to identify the causative organism
- Complete blood count showing elevated white blood cells
- Imaging studies like CT scans, which are particularly valuable as they can show bone erosion and the extent of infection in the mastoid air cells
- MRI may be used in cases where complications like brain abscess are suspected Early diagnosis is crucial as untreated mastoiditis can lead to serious complications including meningitis, brain abscess, facial nerve paralysis, and hearing loss, as noted in 1 and 1. The most recent and highest quality study 1 suggests that mastoiditis treatment traditionally involved cortical mastoidectomy, but there is a recent trend toward nonsurgical management with intravenous antibiotics, either alone or combined with myringotomy and TT insertion and/or needle aspiration of the subperiosteal abscess.
From the Research
Signs and Symptoms of Mastoiditis
- The signs and symptoms of mastoiditis include otalgia, retroauricular symptoms, and otorrhoea 2
- The clinical findings of acute mastoiditis differ according to the causative pathogen 2
- Streptococcus pneumoniae causes severe symptoms, including otalgia and retroauricular symptoms, and leads to mastoidectomy more often than other pathogens 2
- Streptococcus pyogenes causes less otalgia than other pathogens 2
- Pseudomonas aeruginosa particularly affects children with tympanostomy tubes and causes a less aggressive form of disease 2
Diagnosis of Mastoiditis
- Computed tomographic (CT) imaging can show air cell opacification and coalescence, but this appearance is nonspecific and may be seen in patients with infection and tumor 3
- Magnetic resonance imaging (MRI) can aid in differentiating infection and tumor by showing differences in tissue signal characteristics and the presence or absence of an associated soft-tissue mass 3
- Diagnosis of acute mastoiditis is based on clinical, radiological, laboratory, and microbiological findings 2
- Samples for bacterial culture should be obtained prior to antibiotic treatment to identify the causative organism 4
Causative Organisms of Mastoiditis
- The most common pathogens causing mastoiditis are Streptococcus pneumoniae, Streptococcus pyogenes, and Pseudomonas aeruginosa 5, 2
- Other causative organisms include Staphylococcus aureus, Haemophilus influenzae, and anaerobic bacteria 5, 4
- The distribution of causative organisms in acute mastoiditis differs from that in acute otitis media 4