Mastoid effusion is a condition where fluid accumulates within the mastoid air cells, air-filled cavities located in the mastoid process of the temporal bone behind the ear. This fluid buildup is often linked to middle ear infections and can lead to various symptoms.
What Mastoid Effusion Is
The mastoid air cells are numerous interconnected air-filled cavities within the mastoid process, a bony projection behind the ear. These cells are lined with a mucous membrane and connect to the middle ear cavity through the mastoid antrum. This connection helps regulate air pressure within the middle ear, supporting proper sound transmission.
Mastoid effusion primarily arises from infection spreading from the middle ear into these mastoid air cells. Middle ear infections, such as acute otitis media (AOM) or chronic otitis media with effusion (COME), are common causes. When the Eustachian tube, which connects the middle ear to the back of the throat, becomes dysfunctional, it can impair drainage from the middle ear and mastoid air cells, leading to fluid accumulation. Inflammation, often triggered by upper respiratory tract infections or allergies, can also cause swelling and poor drainage, fostering mastoid effusion.
Signs and Symptoms
Individuals experiencing mastoid effusion might notice several symptoms, often resembling those of a middle ear infection. Ear pain or discomfort is common, sometimes throbbing. Hearing may become muffled, or there might be some degree of hearing loss in the affected ear due to fluid interfering with sound transmission. A feeling of fullness or pressure inside the ear is also frequently reported.
Other indicators include discharge from the ear, which may contain pus. A fever, which can be high or increase suddenly, may also be present, signaling an ongoing infection. Headaches are another symptom. Individuals might also experience dizziness or vertigo, a sensation of spinning or imbalance. The area behind the affected ear might show redness, swelling, and tenderness, sometimes causing the ear to protrude.
Diagnosis and Treatment Options
Diagnosing mastoid effusion begins with a physical examination of the ear. A healthcare provider uses an otoscope to look inside the ear, assessing the tympanic membrane for signs of inflammation, bulging, or fluid behind it. This initial visual assessment can indicate middle ear involvement.
Diagnostic steps include hearing tests, such as audiometry, to evaluate any hearing loss. Imaging techniques provide more detailed views of the mastoid bone and its air cells. A computed tomography (CT) scan of the temporal bone is used, as it can reveal fluid within the mastoid air cells and assess for bony changes or erosion. Magnetic resonance imaging (MRI) may also be employed, especially if there is suspicion of infection spreading to surrounding structures, as it identifies intracranial issues like meningeal inflammation.
Treatment for mastoid effusion focuses on addressing the underlying cause. If a bacterial infection is present, antibiotics are the main treatment, sometimes administered intravenously in severe cases. Common antibiotics include amoxicillin or amoxicillin-clavulanate. Watchful waiting may be an option if symptoms are mild and an underlying infection is not clearly indicated, as some effusions resolve spontaneously. Pain management can involve over-the-counter pain relievers like acetaminophen or ibuprofen.
If fluid persists or if the infection is severe, surgical interventions may be considered. A myringotomy involves making a small incision in the eardrum to drain fluid from the middle ear. Tympanostomy tubes, or ear tubes, may be inserted to maintain drainage and ventilate the middle ear, usually falling out on their own within six months to a year. For more complex or chronic cases, or if antibiotics and myringotomy are ineffective, a mastoidectomy may be performed. This surgical procedure involves removing infected tissue from the mastoid air cells to clear the infection and prevent further spread.
Potential Complications
If mastoid effusion is left untreated or if initial treatments are not effective, several complications can arise due to the infection spreading beyond the mastoid air cells. Chronic ear infections are a risk, which can recur frequently. Persistent fluid and inflammation can lead to permanent hearing loss in the affected ear.
A cholesteatoma, an abnormal skin growth in the middle ear, can also develop, blocking fluid drainage and exacerbating the condition. The infection may spread to surrounding areas, causing more severe issues. This can include facial nerve paralysis, which affects facial muscle movement. Intracranial complications are also a concern, such as meningitis, an infection of the membranes covering the brain and spinal cord, or a brain abscess, a collection of pus within the brain. The infection can also lead to bone erosion within the mastoid, further damaging the temporal bone.