The Link Between CF and Ear Infections

Otitis media, more commonly known as middle ear infections, is a prevalent infection that usually occurs in childhood. In fact, otitis media is the most prevailing childhood infection in the United States for which antibiotics are prescribed.¹ Chances are, you know someone who has experienced an ear infection at some point. For most people, otitis media is acute in nature and resolves within 72 hours. However, a minority of people go on to develop chronic and persistent ear infections.

It is estimated that between 3-43% of children with cystic fibrosis (CF) have had at least one occurrence of a middle ear infection.² There are many speculations that CF can increase the frequency of ear infections, leading to chronic otitis media. Theoretically, an impairment of airway clearance defenses should negatively affect the ear, right?

What is chronic otitis media?

Chronic otitis media is defined as a recurrent infection of the middle ear, which usually develops from inflammation following a viral upper respiratory tract infection. Sometimes it can occur due to the presence of a  cholesteatoma, a non-cancerous mass in the middle ear which can be congenital or acquired through eardrum rupture.³ The exact timeframe at which acute otitis media develops into chronic otitis media is not well defined, but it is generally accepted to be a period between 2 weeks to 3 months after the development of acute otitis media.¹

Pathophysiology

The Eustachian tube connects the middle ear to the back of the throat and the nasal cavity. If this tube is obstructed, for example as observed with frequent respiratory tract infections and seasonal allergies, it can cause middle ear dysfunction. This obstruction makes it difficult for air to circulate in and out of the middle ear, resulting in a pressure difference. If the pressure difference becomes too great, the eardrum can rupture. A ruptured eardrum is essentially a hole in the eardrum, leading to multiple symptoms.^1,3

Symptoms

Symptoms of chronic otitis media include:³

• Vertigo, or a sensation of dizziness or spinning
• Hearing loss, which is often temporary until the eardrum is able to heal
• Ear drainage
• Sensation of ear fullness
• Ear pain

What's the link between cystic fibrosis and ear infections?

CF often causes chronic inflammation and recurrent infections of the nasal sinuses and respiratory tract.¹ While we know that sinus infections increase the risk of ear infections in the general population, it is interesting to note that studies have not shown that people with CF have a greater frequency of ear infections. Many of these studies have highlighted that the frequency of ear infections in CF is the same as in the general population when adjusted for age.⁴

Researchers speculate that this is because the impaired mucous transport we see in CF does not affect the ear mucosa as much as it does the nasal epithelium.⁴ This highlights that while there has been much research surrounding the pathophysiology of CF, there are still many aspects of the condition that we have no concrete answers for.

Do you or your loved one with cystic fibrosis get ear infections? Share your experience with us!