Otitis Media Causes: From Cold to Sinusitis

Dr. K. R. Meghanadh

Introduction: What is Otitis Media? Why is it Important?

Otitis Media, often referred to as a middle ear infection, is a widespread issue affecting individuals across all age demographics. Recognizing the underlying Otitis media causes is essential for effective treatment and preventive measures.

Anatomy of the Middle Ear

Think of the middle ear as a tiny box, roughly the size of a cubic centimeter, enclosed by bones on five sides, with the sixth being the eardrum. For optimal hearing, it's crucial for the eardrum to move freely, which requires a balance of air pressure inside and outside this chamber. Here's where the eustachian or auditory tube comes into play, maintaining this delicate balance by allowing air to move from the nasopharynx—located at the back of your nose—into the middle ear.

How Middle Ear Anatomy Relates to Ear infection

As noted before, the eustachian tube (the auditory tube) links the middle ear to the back of the nose or the nasopharynx. If there's a problem with this tube or with the nasopharynx, it can disrupt the flow of air to the middle ear. When that happens, the pressure inside the ear can get out of balance, causing discomfort or pain. It can also lead to fluid building up in the middle ear, which becomes a perfect place for bacteria to grow, causing middle ear infections.

Additionally, if you have a nose infection, the mucus filled with bacteria can either block the eustachian tube or even flow into the middle ear. This creates more chances for an infection to develop.

Furthermore, the lining of the eustachian tube is made of mucus that can become inflamed for various reasons, such as allergies or smoking. Inflammation can partially or entirely block the tube, making the middle ear more susceptible to infection.

Why Babies Are at Higher Risk?

A middle ear infection is common in babies below six months. Babies below six months have small skulls to accommodate easy birth. Their little heads do not have enough space to align the eustachian tubes at an angle like in adults. The horizontal alignment of the eustachian tube increases the risk of middle ear infection as infected fluids can easily leak into the middle ear. Babies enjoy the sweet taste of milk and prefer to sleep with it in their mouths.

Milk ferments or spoils faster due to bacteria that dwell in our mouths. The fermented milk can slip into the nasopharynx, from where it can leak into the nose or middle ear. If the spoiled milk slips into the nose, the baby can get rhinitis or a cold. If they slip into the middle ear, they will get an ear infection. Please read our article on “What causes otitis media in a baby?” to understand more.

How Kids Get Middle Ear Infections - Adenoids

Children can have adenoids, i.e., extra tissue formed due to allergy or viral infections at the back of the nose or nasopharynx. Adenoids are like tonsils tissue, enlarged tissue that causes problems. The middle ear is like a cube with 2 cm on each side. The presence of adenoids in such a small area can disturb the eustachian tube, often resulting in middle ear infections in kids.

General Otitis Media Causes

Cold - Nasal infections

As mentioned earlier, any nasal infection can affect the middle ear. The common cold is the leading cause of not just middle ear infections but also ear infections in general.

When you get a cold, mucus can move from the back of your nose into your eustachian tube, the canal connecting your nose to your middle ear. Once this mucus reaches the middle ear, it can lead to an infection known as Otitis media.

90% of ear infections travel from the nose to the ear, making middle ear infections a common occurrence when you have a cold.

Blowing your nose hard with one nostril block when you have cold

Blowing your nose too hard, especially when one nostril is blocked, can create a lot of pressure in the back of your nose. This area is known as the nasopharynx. The high pressure can push infected fluid from the nasopharynx into your middle ear through the eustachian tube.

Once the fluid gets into the middle ear, it can get stuck and become a perfect place for bacteria to grow. This can lead to a middle ear infection, also known as Otitis media.

Chronic Sinusitis

In chronic sinusitis, your body's immune system may adapt to manage the infection without completely getting rid of it. This differs from acute sinusitis, where your nose tends to flush out the fluids.

In chronic cases, the fluid tends to move from the back of your nose into your throat. This area, known as the nasopharynx, is also where the opening of the eustachian tube is located, connecting your nose to your middle ear.

If the mucus is thick, it can block this tube, creating negative pressure in the middle ear. This pressure imbalance can cause ear pain and potentially lead to an infection.

On the other hand, if the fluid is thin, it can easily travel through the eustachian tube to the middle ear, creating an opportunity for infection.

So whether the mucus is thick or thin, its presence in the eustachian tube can increase the risk of causing a middle ear infection.

Allergy

When you have an allergy, various parts of your respiratory system, like your nose, throat, and lungs, can be affected. These areas are all connected by a layer of skin called the mucosa.

This mucosa also lines the back of your nose and extends into the eustachian tube, a small canal that links your nose to your middle ear. During an allergic reaction, the mucosa can become swollen. This swelling can narrow or partially block the eustachian tube.

When the tube is blocked, air can't circulate properly to the middle ear. This creates negative pressure, causing fluid from your blood to leak into the middle ear. Once there, the fluid can become a breeding ground for bacteria, leading to Otitis Media.

Obstructions in the Nasopharynx

The middle ear is linked to the back of your nose, known as the nasopharynx, via a small tube called the eustachian or auditory tube. Normally, air flows into the middle ear through this tube when we swallow.

However, if there's a mass or obstruction in the nasopharynx, it can block the opening of the eustachian tube. This prevents air from entering the middle ear, leading to a build-up of negative pressure inside it.

As a result, fluid from the blood can leak into the middle ear, where it can get stuck. This stagnant fluid then becomes an ideal place for bacteria to grow, resulting in a middle ear infection known as Otitis Media.

Going to a hilly area at high speed

High-speed elevator

Diving into the water

Travelling in flight

Whether you're speeding up a mountain, taking a high-speed elevator, diving into water, or flying in a plane, you're experiencing quick changes in air pressure.

If your eustachian tube is partially blocked, perhaps due to allergies, congenital variation, or sinusitis, it may struggle to balance the air pressure in your middle ear with the rapidly changing external air pressure.

This mismatch in pressure can cause fluid from your blood to leak into your middle ear. Once the fluid is in the middle ear, it can become trapped and stagnant. This provides an ideal environment for bacteria to multiply, leading to a middle ear infection called Otitis Media.

Smoking

Active and passive smoking can cause mucosa inflammation, a lining that connects your nose, throat, the back of your nose (nasopharynx), voice box, and lungs. This same mucosa also lines the eustachian or auditory tube, which connects the nasopharynx to the middle ear.

When you smoke or are exposed to smoke, the mucosa can become inflamed. This inflammation can lead to a blockage in the eustachian tube, creating negative pressure in the middle ear.

This negative pressure can then cause fluid from your blood into your middle ear. Once there, the fluid can become stagnant, providing a perfect environment for bacteria to grow. This can result in a middle ear infection known as Otitis Media.

Dr. K. R. Meghanadh