What is Bullous Myringitis?
Bullous myringitis is a fairly common infection that leads to the formation of fluid-filled bumps or blisters on the eardrum, which is also known as the tympanic membrane. This infection does not affect the outer or middle ear. If the middle ear is infected, it is identified as acute otitis media, not bullous myringitis. Since the eardrum has many nerve endings, it’s typical for people with this condition to experience moderate to severe ear pain.
The symptoms can be similar to those of acute otitis media, including redness and swelling of the eardrum, diminished or no visible reflection of light off the eardrum, and less visible eardrum movement. There can also be bloody ear discharge if a blister bursts, a condition known as bullous hemorrhagic myringitis. However, the bursting of a blister often reduces the associated pain.
Recent research suggests that the main cause of bullous myringitis is usually viruses. Even though one study suggested the bacteria mycoplasma pneumoniae might cause it, further studies have not confirmed this.
What Causes Bullous Myringitis?
Bullous myringitis is mainly thought to be caused by viruses, although the most frequently identified bacteria is Streptococcus pneumoniae. Other bacteria that can cause it include Haemophilus influenzae, Moraxella catarrhalis, Group A Streptococcus, and Staphylococcus aureus. Viral causes mostly include Respiratory Syncytial Virus (RSV) or influenza viruses.
In situations where ear infections reoccur, many different bacteria can be involved, and it’s possible to have both a bacteria and virus causing the infection at the same time. Some less common causes include varicella, Epstein-Barr virus, measles, mycoplasma, and fungi.
Bullous myringitis can also happen after the middle ear space is irritated by chemicals, while the eardrum itself stays intact.
Streptococcus pneumoniae is more likely to be involved in cases of bullous myringitis compared to usual acute ear infections.
Risk Factors and Frequency for Bullous Myringitis
Bullous myringitis, a condition affecting the ear, happens a lot during winter, particularly because certain functions of the ear get affected in colder climates. It’s seen more in adolescent girls and older children, but is more often seen in boys who are very young. Commonly, boys aged 2 to 8 years old get it, while AOM (a similar ear-related complication) tends to appear in children under two years of age. A small percentage, around 5.7% of patients under 2 years old with AOM, end up with bullous myringitis, which translates roughly into 1 case of bullous myringitis after every 20 cases of AOM.
In 2017, out of the estimated 5 million US children affected by AOM, about 400,000 cases of bullous myringitis were reported. It’s not uncommon for patients to have bullous myringitis in both ears, and those that do have it are three times more likely to get AOM again.
- Bullous myringitis is most common during the winter months.
- It is more common among girls in their adolescence and older children.
- Young boys, typically between ages 2 to 8, are more prone to this condition.
- AOM is most commonly seen in children under 2 years of age.
- Approximately 5.7% of AOM patients under 2 years old could have bullous myringitis.
- In 2017, out of the 5 million US children affected by AOM, about 400,000 cases of bullous myringitis were reported.
- Up to 16% of patients can have bullous myringitis in both ears, and they are three times more likely to get AOM again.
Signs and Symptoms of Bullous Myringitis
Bullous myringitis is a type of ear infection with the primary symptom being intense and sudden ear pain. The pain can be sharp or pulsating, and might even spread to areas like the mastoid process (area behind the ear), the back of the head, the jaw joint, or rarely, the face. This condition tends to be more painful than other types of ear infections found in children.
For children younger than two, who cannot express the feeling of pain, other signs may show up. These can include ear rubbing, restless sleeping, excessive crying, and poor feeding. It’s also common to see accompanying symptoms like a runny nose (in about 93% of cases) and cough (in about 73% of cases). The specific bacteria causing the infection doesn’t alter the way symptoms show up.
The classic sign, characteristic to bullous myringitis, is the appearance of blisters (known as bullae) on the eardrum. Other signs can include fever, swelling, and redness of the eardrum, a diminished or absent light reflex, and decreased ear mobility. If blisters are found in the ear canal or on the outer ear, other conditions, like Ramsay-Hunt syndrome or bullous dermatitis, might be considered. Conductive hearing loss can also happen if there is fluid in the ear. More than half of patients with bullous myringitis show sensorineural hearing changes, although the cause is unclear. Generally, earaches and fever are more common in bullous myringitis than in other types of ear infections.
Diagnosis of bullous myringitis is typically based on clinical symptoms, particularly the presence of one or more blisters on the eardrum. Other findings such as another ear infection are irrelevant for the diagnosis. No lab tests or imaging are essential for diagnosing bullous myringitis. However, in specific cases, a procedure called tympanocentesis might be used to confirm fluid in the middle ear and to identify the bacteria causing the infection. Aspiration of the blisters may also help in relieving pain. Otoscopic visualization (looking into the ear with a special instrument) forms the basis of diagnosis, but other studies, like using a pneumatic otoscope, tympanometry, and acoustic reflectometry are available, although rarely indicated in isolated bullous myringitis.
Testing for Bullous Myringitis
Bullous myringitis diagnosis primarily depends on a physical examination via a device called an otoscope.
Blood tests and other laboratory procedures are usually not required for diagnosing bullous myringitis. However, in rare instances, like in infants younger than 28 days who have a fever along with acute bullous myringitis, further lab tests might be recommended. These tests will be performed following the guidelines from the American Academy of Pediatrics to check if any other systemic or congenital diseases are present.
In most cases, there’s no need for imaging studies like CT scan or MRI. But if there are suspicions of complications like mastoiditis, abscesses in the brain or epidural area, meningitis, or cholesteatoma, these studies could be helpful.
Tympanocentesis, a procedure that involves puncturing the eardrum to drain fluid, is not commonly done. It can, however, be beneficial for newborns or very sick children at a higher risk of negative outcomes – not only to get a sample for testing but also to ease the pain.
Treatment Options for Bullous Myringitis
Bullous myringitis treatment and outcomes are quite similar to middle ear infections without bullae, apart from the fact that pain management may need to be more intensive. The usual “wait and watch” approach taken with regular ear infections might not be suitable for bullous myringitis, due to higher chances of the infection returning and the fact that the majority of patients have a bacteria-positive fluid buildup in their middle ear. Because of this, the main course of treatment usually involves systemic antibiotics and close outpatient follow-up.
The American Academy of Pediatrics suggests using amoxicillin as the first line of defense in treating this kind of ear infection, as long as the patient hasn’t been taking amoxicillin in the past 30 days. High-dose amoxicillin is preferred because it can reach a high concentration in the middle ear and potentially be more effective. If a patient has recently been on amoxicillin, a different medication, amoxicillin-clavulanic acid, is the preferred treatment. For patients with a penicillin allergy, alternatives like azithromycin, clarithromycin, cefdinir, cefpodoxime, or cefuroxime can be prescribed.
Some cases have shown good recovery with no hearing loss when treated with a combination of topical steroids, topical antibiotics, and systemic antibiotics. However, steroids aren’t currently recommended as a routine part of treatment for bullous myringitis.
Despite the lack of well-designed randomized studies, a recent review found that surgery might be a more effective treatment than topical treatments or laser-assisted treatments for myringitis.
As bullous myringitis patients often experience hearing loss, it’s recommended for them to undergo a test called a pure tone audiogram to determine the extent and type of hearing loss they’re experiencing. Right now, there isn’t enough proof to back up the use of systemic steroids in recovering hearing loss.
In some severe cases where the condition is unresponsive to treatment or there are potential complications looming, myringotomy, a surgical procedure to relieve pressure from the middle ear, might become necessary.
What else can Bullous Myringitis be?
Doctors diagnosing bullous myringitis, an ear condition characterized by painful blisters on the eardrum, need to be keen during the physical examination to accurately identify the illness. The symptoms of bullous myringitis can be similar to those of other issues such as otitis media with effusion (OME) – which is fluid trapped behind the eardrum, as well as skin conditions that also manifest in blister formation like bullous pemphigoid and pemphigus vulgaris.
The blisters in bullous myringitis can sometimes be mistaken for vesicles (small, fluid-filled sacs), and this may point to a different ailment such as the Ramsay-Hunt syndrome, a disorder caused by a virus. Beside these, other conditions that the doctor should rule out include:
- Acute suppurative otitis media – an infection in the middle ear
- Otitis externa – inflammation of the outer ear and ear canal
- Granuloma – an inflammation in the tissue
- Acute mastoiditis – a bacterial infection that affects a part of the skull behind the ear
The accuracy of the physical exam is critical to distinguishing these conditions from bullous myringitis.
What to expect with Bullous Myringitis
Bullous myringitis, similar to a certain type of ear infection without small blisters, generally has a positive outcome. Symptoms like hearing loss and unsteadiness typically only last for a short period and improve once the infection clears up.
Most people (95%) report that their pain subsides by the third day and that any ear discharge stops by the fifth day. However, it’s worth noting that clearing up the fluid in the middle ear can take as long as five weeks.
Possible Complications When Diagnosed with Bullous Myringitis
Bullous myringitis can lead to several complications, similar to those of acute otitis media (inflammation of the middle ear) without blisters on the eardrum. The most common issue is hearing loss. However, some rare but serious complications can also occur. In some patient groups, doctors also found a tough-to-treat bacterial infection caused by drug-resistant Streptococcus pneumoniae.
Possible complications include:
- Hearing loss
- Subperiosteal abscess (a pocket of pus that forms beneath a layer of bone in the ear)
- Labyrinthitis (inflammation in the inner ear)
- Facial weakness
- Mastoiditis (infection in the bone behind the ear)
- Post-auricular cellulitis (skin infection behind the ear)
- Epidural abscess (a pocket of pus near the spinal cord)
- Meningitis (swelling of the protective membranes covering the brain and spinal cord)
- Sigmoid sinus thrombosis (a blood clot in a specific vein within the brain)
Preventing Bullous Myringitis
It’s crucial to educate patients about fully completing their antibiotics and ensuring they follow up with their regular doctor. They must be aware that if their symptoms worsen, even after taking pain medication and antibiotics correctly, this is a warning sign they need to return for further treatment. This approach is highly recommended to avoid any potential health risks.
