Definition

Mastoiditis is an infection targeting the temporal bone, particularly the mastoid air cells. The temporal bone, situated just behind the ear, contains these hollow, septated structures resembling a honeycomb. These mastoid air cells are interconnected with the middle ear.

Causes

Mastoiditis typically arises as a complication from middle ear infections (otitis media). For mastoiditis to develop, recurrent episodes of otitis media are often necessary. Additionally, cholesteatoma, characterized by the accumulation of skin cells within the ear canal, can precipitate mastoiditis. This condition impedes the ear's natural cleaning process, facilitating infection spread to the mastoid, where it can erode the barriers within the air cells, enlarging them and filling them with pus.

Streptococcus pneumoniae is the predominant bacterium responsible for mastoiditis. Other bacterial agents include group A beta-hemolytic Streptococcus, Staphylococcus aureus, Streptococcus pyogenes, and Haemophilus influenzae.

Risk factor

Mastoiditis is more prevalent in children, particularly those under the age of two, compared to adults. Additional risk factors include:

• Compromised immune system
• Recurrent middle ear infections
• Incomplete development of mastoid air cells

Symptoms

Children with mastoiditis typically exhibit symptoms such as irritability, drowsiness, fever, ear tugging, and ear pain. In contrast, adults often report severe ear pain, fever, and headache. Additional symptoms may include:

• Redness, warmth, and pain behind the ear
• Swelling behind the ear, making it appear more prominent
• Fluid discharge from the ear
• Fever, irritability, and fatigue (particularly in children)
• Reduced hearing in the affected ear 

These symptoms usually emerge following repeated or particularly severe ear infections.

Diagnosis

Ear Examinations

The doctor typically uses an otoscope to diagnose mastoiditis, a device equipped with a light and magnifying glass, to examine the ear canal. The doctor will also inspect the area behind the ear for signs of swelling.

Diagnostic Testing

Laboratory and imaging tests are commonly employed to identify complications associated with mastoiditis.

Laboratory tests may include:

• Complete blood count with white blood cell differential
• Erythrocyte sedimentation rate
• C-reactive protein (CRP)

Suppose an abscess containing pus is detected (in regions such as the neck, ear, mastoid, or spine). In that case, it will be drained and cultured in the laboratory to identify the causative bacteria and determine the appropriate antibiotic treatment to fight the bacteria.

Imaging studies, such as X-rays or computed tomography (CT) scans, may be utilized depending on their availability at the healthcare facility. A referral for a CT scan may be necessary, as not all facilities are equipped with these technologies. CT scans involve the use of X-rays and computer assistance to generate detailed images of the body part under examination.

Management

Antibiotic Therapy

The primary treatment for mastoiditis involves the administration of antibiotics. Patients with mastoiditis may require hospitalization for intravenous antibiotic therapy. In addition to antibiotics, intravenous steroids may be administered. General practitioners will typically refer patients to an ear, nose, and throat specialist for comprehensive evaluation and management.

Surgical Intervention

Depending on the severity of the infection, various surgical interventions may be necessary. These include myringotomy, tympanostomy tube insertion, and mastoidectomy. Myringotomy involves making an incision in the eardrum to allow pus drainage and is feasible only if the eardrum is intact. In mastoiditis cases, the eardrum may be either perforated or intact. Tympanostomy tube insertion involves placing a tube through the eardrum into the middle ear to facilitate pus drainage. Mastoidectomy entails the surgical removal of infected mastoid air cells.

In uncomplicated mastoiditis cases, the combination of antibiotics, steroids, and myringotomy with tympanostomy tube insertion is usually adequate. Continuous monitoring is essential during treatment, as the patient's condition can deteriorate rapidly. If no improvement is observed within 48 hours, mastoidectomy may be considered.

Postoperative care requires a rest period of 7-10 days. Key considerations include:

• Keeping the operated ear dry to ensure proper wound healing.
• Avoid hair washing until the doctor grants permission, typically one week after surgery, taking care to prevent water from entering the ears.
• Refraining from swimming for 4-6 weeks following surgery to minimize the risk of water exposure, contingent on the ear's healing progress.

Complications

The spread of mastoiditis infection can result in fatal complications because the infection could spread to various sites. The spread of infection can be classified into two primary groups, extracranial (external to the cranial cavity) spread and intracranial (within the cranial cavity) spread.

Extracranial complications may include:

• Abscess (pus-filled sacs) formation near the mastoid on the external surface of the skull
• Facial nerve paralysis resulting from nerve compression
• Labyrinthitis, due to infection spreading to the inner ear, manifesting as vertigo and hearing loss from nerve inflammation
• Petrous apicitis, where the infection spreads to other skull regions, presenting with ear discharge, retro-ocular pain, unilateral eye muscle paralysis, and other neurological symptoms
• Bezold's abscess, an abscess forming in the fascia covering the neck muscles

Meanwhile, intracranial complications encompass:

• Abscesses within the temporal lobe, cerebellum, or meninges
• Meningitis, an infection of the meningeal layers
• Venous sinus thrombosis, characterized by impaired venous blood flow in the brain

Clinical manifestations of these complications may include seizures, severe headaches, and impaired consciousness.

Prevention

Proactive management of ear infections can effectively prevent the development of mastoiditis. Early intervention is critical for individuals experiencing recurrent ear infections to avoid mastoiditis. Standard therapy for ear infections includes a 7-10 day regimen of antibiotics, as prescribed by healthcare professionals.

When to see a doctor?

Prompt medical attention is essential if:

• Mastoiditis symptoms are experienced
• Ear infections persist despite treatment or are accompanied by new symptoms
• Diagnosed mastoiditis does not respond to therapy

Failure to treat mastoiditis adequately can lead to severe, life-threatening outcomes. Hence, it is imperative to address infections in the outer, middle, or inner ear and mastoiditis without delay.