What Is Acute Otitis Media? Symptoms, Causes & Treatment

An ear infection (acute otitis media or AOM) is an infection of the middle ear, the air-filled space behind the eardrum. It often develops after a cold, flu, or another upper respiratory infection, causing fluid to build up behind the eardrum and become infected by viruses or bacteria.

Ear infections are especially common in children, but adults can develop them too. In this guide, we'll explain the symptoms, causes, treatments, potential complications, and when it's time to seek medical advice.

Key Takeaways

• Acute otitis media (AOM) is a middle ear infection caused by viruses or bacteria trapped behind the eardrum.
• Common symptoms include ear pain, fever, hearing changes, ear pressure, and fluid build-up in the middle ear.
• Children are more likely to develop ear infections because their Eustachian tubes are shorter and narrower.
• Most ear infections improve within a few days, but some cases may require antibiotics or medical assessment.
• Persistent symptoms, worsening pain, ear discharge, or hearing loss should always be checked by a healthcare professional.

Understanding Ear Anatomy

To understand how an ear infection develops, it helps to know the basic anatomy of the ear:

When the Eustachian tube becomes blocked, fluid can become trapped inside the middle ear. This creates an environment where viruses or bacteria can multiply, leading to infection.

Types of Otitis Media

Not all ear infections are the same. The main types of otitis media include:

Acute Otitis Media (AOM)

This is the most common type:

• Sudden onset
• Ear pain
• Inflammation
• Fluid behind the eardrum
• May be viral or bacterial

Otitis Media With Effusion (OME)

Also known as glue ear. This occurs when fluid remains trapped behind the eardrum after an infection has cleared.

Symptoms may include:

• Muffled hearing
• Ear fullness
• Balance problems

Usually, there is no active infection.

Chronic Suppurative Otitis Media (CSOM)

A long-term or recurring middle ear condition. It may involve:

• Repeated infections
• Ongoing inflammation
• Persistent fluid build-up
• Damage to the eardrum

Symptoms of Acute Otitis Media

Ear infection symptoms can vary depending on age and severity. Common symptoms of AOM include:

Signs in Children

• Pulling or rubbing the ear
• Crying more than usual
• Irritability
• Difficulty sleeping
• Reduced appetite
• Fever
• Balance problems
• Not responding to sounds as normal

Pharmacist explains: Because children have shorter and narrower Eustachian tubes, they are more likely to develop middle ear infections than adults.

Signs in Adults    

• Sharp or throbbing ear pain
• Hearing changes
• Ear pressure
• Dizziness
• Mild fever
• Ear discharge
• Headaches (see our expert tips on how to get rid of a headache)
• Difficulty concentrating due to discomfort

What Is Acute Otitis Media Caused By?

It’s primarily caused by viruses or bacteria that become trapped behind the eardrum after an upper respiratory illness, such as:

• Cold (by the way, learn everything you need to know about the common cold)
• Flu
• Sinus infections
• Allergies

Common Viruses Responsible for AOM

• Rhinovirus (common cold)
• Influenza virus (flu)
• Respiratory syncytial virus (RSV)
• Adenovirus

Common Bacteria Responsible for AOM

• Streptococcus pneumoniae
• Haemophilus influenzae
• Moraxella catarrhalis

In many cases, it's impossible to know whether an ear infection is viral or bacterial without medical assessment.

Stages of Acute Otitis Media

Acute otitis media doesn't usually develop all at once. In many cases, the infection progresses through several stages as fluid builds up behind the eardrum and the body's immune system responds.

Stage 1: Eustachian Tube Blockage

The infection often begins when inflammation causes the Eustachian tube to swell and become blocked. This prevents air from entering the middle ear and stops fluid from draining normally.

Common symptoms:

• A feeling of fullness or pressure in the ear
• Mild ear discomfort
• Slight hearing loss

Stage 2: Inflammation & Fluid Build-Up

As inflammation increases, fluid begins to collect behind the eardrum. At this stage, viruses or bacteria may start multiplying within the trapped fluid.

Common symptoms:

• Increasing ear pain
• Fever
• Reduced hearing
• A feeling of pressure inside the ear

Stage 3: Pus Formation & Pressure

The immune system responds to the infection by sending white blood cells to the middle ear. This can lead to pus building up behind the eardrum, increasing pressure within the ear.

Common symptoms:

• Severe throbbing ear pain
• Higher fever
• Irritability (especially in children)
• More noticeable hearing loss

Stage 4: Eardrum Perforation

In some cases, pressure becomes so great that the eardrum develops a small tear (perforation), allowing fluid or pus to drain from the ear.

Common symptoms:

• Sudden relief of ear pain
• Ear discharge (which may be yellow, white, or blood-stained)
• Improved pressure sensation
• Reduced fever

Stage 5: Resolution & Recovery

In most cases, the infection gradually clears, inflammation settles, and the eardrum heals naturally. Any remaining fluid behind the eardrum is usually absorbed over time.

Common symptoms:

• Gradual improvement in pain and hearing
• Disappearance of fever
• Reduced or absent ear discharge

Pharmacist explains: Although most ear infections resolve without complications, untreated infections can occasionally spread to nearby structures and cause more serious problems. This is why persistent symptoms, worsening pain, or ongoing hearing loss should always be assessed by a healthcare professional.

Possible Complications

• Perforated eardrum
• Hearing loss (usually temporary)
• Spread of infection (e.g., mastoiditis)

How Is Acute Otitis Media Treated?

Treatment depends on age, symptom severity, and how long symptoms have been present.

Pain Relievers

Pain is often the symptom that causes the most discomfort. Over-the-counter pain relievers (such as ibuprofen or paracetamol) may help manage:

• Earache
• Fever
• Headaches

Antibiotics

Antibiotics are not always required. They may be considered when:

• Symptoms are severe
• Symptoms persist
• Young children are affected
• Certain complications are suspected

Self-Care Measures

Many mild ear infections improve without antibiotics. Helpful measures include:

• Rest
• Drinking plenty of fluids
• Applying a warm compress
• Managing pain and fever

What Should You Avoid During an Ear Infection?

While recovering, it's sensible to:

• Avoid inserting cotton buds or objects into the ear.
• Avoid smoking or second-hand smoke exposure.
• Avoid ignoring worsening symptoms.
• Avoid excessive water exposure if the eardrum has perforated.

Acute Otitis Media — Summary

Ear infections are common and often clear up on their own, but ongoing pain, fever, or hearing changes should never be ignored.

If you're experiencing earache or think you may have an ear infection, use Weldricks’ ear infection treatment service to access expert assessment and treatment advice without needing a GP appointment!