Swimmer's Ear

What Is Swimmer's Ear?

Swimmer's ear — known medically as otitis externa — is an infection or inflammation of the external ear canal, the narrow passage that runs from the outer ear (pinna) to the eardrum (tympanic membrane). Although the name suggests a condition exclusive to swimmers, otitis externa can affect anyone at any age. It is called "swimmer's ear" because prolonged water exposure is one of the most common triggers, but the condition has many other causes, from cotton bud use to ear wax disruption, skin conditions, and even regular hearing aid wear.

Otitis externa is one of the most frequent ear complaints seen in UK general practice. According to NICE Clinical Knowledge Summaries, it is estimated to affect around 1 in 10 people at some point in their lives, with an annual incidence in the UK of approximately 1% of the population. The condition shows a marked seasonal pattern, peaking during the summer months when swimming and water-based activities increase. It is most common in adults aged 45 to 75, though children and young adults who swim regularly are also at elevated risk. The British Society of Audiology (BSA) notes that otitis externa accounts for a significant proportion of all ear-related GP consultations in the UK, making it an important condition for both clinicians and the public to understand.

How the Ear Canal Protects Itself

To understand why swimmer's ear develops, it helps to know how the ear canal normally defends against infection. The ear canal is lined with delicate skin that produces cerumen — commonly known as ear wax. Far from being a nuisance, cerumen is a sophisticated defence mechanism. It forms a thin, slightly acidic coating (pH 4 to 5) across the canal skin that performs several protective functions:

• Water repellent barrier: Cerumen creates a hydrophobic layer that prevents water from soaking into the canal skin and causing maceration (softening and breakdown)
• Antibacterial and antifungal properties: The acidic pH of healthy ear wax inhibits the growth of bacteria and fungi — the organisms responsible for most ear canal infections
• Physical protection: Ear wax traps dust, debris, and dead skin cells, carrying them outwards through the ear canal's natural self-cleaning migration process
• Lubrication: Cerumen keeps the canal skin supple and prevents dryness and cracking, which could otherwise provide entry points for infection

When this protective cerumen layer is disrupted — whether by water, physical trauma, chemical irritation, or skin disease — the ear canal becomes vulnerable to infection. Understanding this mechanism is central to both treating and preventing swimmer's ear.

Causes of Swimmer's Ear

Otitis externa develops when the ear canal's natural defences are compromised, allowing bacteria or fungi to colonise the exposed skin. The main causes and risk factors include:

Water Exposure

Prolonged or repeated contact with water is the classic trigger. Swimming in pools, lakes, rivers, or the sea allows water to enter the ear canal, where it can become trapped — particularly if the canal is narrow or if cerumen is present in an amount that partially blocks drainage. The trapped water softens and macerates the canal skin, washing away the protective cerumen layer and raising the pH to a level more favourable for bacterial growth. Chlorinated pool water can be particularly irritating, as can contaminated natural water sources. Even regular showering or bathing can contribute if water frequently enters the ears.

Cotton Buds and Ear Canal Trauma

One of the most common causes of otitis externa in the UK has nothing to do with swimming. Inserting cotton buds, fingers, hair grips, pen caps, or any other objects into the ear canal can scratch or abrade the delicate canal skin, removing the protective wax layer and creating micro-wounds through which bacteria can enter. The NHS strongly advises against inserting anything into the ear canal. Despite this advice, cotton bud use remains widespread — a factor that contributes significantly to the UK's otitis externa burden.

Hearing Aids, Ear Plugs, and In-Ear Headphones

Devices that sit inside the ear canal can contribute to otitis externa in several ways. Hearing aid moulds trap moisture against the canal skin, disrupt the natural wax migration process, and create a warm, humid micro-environment that encourages microbial growth. In-ear headphones and ear plugs — including noise-cancelling devices worn for extended periods — have similar effects. People who wear hearing aids regularly should be aware of this risk and take steps to mitigate it (discussed in the prevention section below).

Skin Conditions

Pre-existing skin conditions affecting the ear canal — including eczema, psoriasis, seborrhoeic dermatitis, and contact dermatitis (from hair products, earrings, or hearing aid materials) — disrupt the skin's integrity and make it more susceptible to secondary infection. These conditions can cause chronic or recurrent otitis externa that requires treatment of the underlying skin disorder alongside the infection.

Bacterial vs Fungal Swimmer's Ear

While most cases of otitis externa in the UK are bacterial, a significant minority are caused by fungi — a presentation known as otomycosis. Recognising the difference matters because the two types require different treatments.

Bacterial Otitis Externa

The majority of swimmer's ear infections are caused by bacteria. The most common organisms are Pseudomonas aeruginosa (a water-loving bacterium particularly associated with swimming-related infections) and Staphylococcus aureus. Bacterial otitis externa typically presents with acute-onset pain, redness, swelling, and discharge that may be yellowish or greenish. It responds well to topical antibiotic ear drops, usually combined with a corticosteroid to reduce inflammation.

Fungal Otitis Externa (Otomycosis)

Fungal otitis externa is increasingly recognised in the UK and is thought to account for up to 10% of otitis externa cases. The most common causative organisms are Aspergillus species (particularly Aspergillus niger, which produces characteristic dark spores visible in the ear canal) and Candida species. Otomycosis is more common in warm, humid climates, but UK cases are not rare — and may be increasing due to widespread use of antibiotic ear drops, which can eliminate competing bacteria and allow fungi to proliferate. Symptoms of fungal otitis externa often include intense itching (more prominent than pain), a feeling of fullness, white or dark discharge, and flaky or "wet newspaper" debris in the canal. Treatment requires antifungal ear drops or cream (typically clotrimazole) rather than antibiotics, and resolution can be slower, sometimes requiring several weeks of treatment and follow-up.

Symptoms and Diagnosis

Swimmer's ear has a characteristic set of symptoms that often allows a confident clinical diagnosis. Recognising these symptoms early leads to faster treatment and less discomfort.

Key Symptoms

• Ear pain (otalgia): Often severe and characteristically worsened by pulling the pinna (outer ear) or pressing on the tragus — the small cartilage flap in front of the ear canal opening. This feature is the single most reliable way to distinguish otitis externa from a middle ear infection, where ear manipulation does not typically increase pain
• Itching: Frequently an early symptom before pain develops, particularly in fungal cases. Many people initially assume the itching is caused by dry skin or wax build-up
• Discharge: May be clear, yellowish, greenish, or foul-smelling in bacterial infections, or white, grey, or dark and flaky in fungal infections
• Redness and swelling: The ear canal skin becomes visibly inflamed. In moderate to severe cases, the canal may swell shut, making it difficult or impossible to see the eardrum
• Hearing loss: Temporary hearing reduction occurs when swelling, debris, or discharge partially blocks the ear canal. This is conductive in nature and resolves once the infection clears
• Fullness or blockage: A sensation of the ear being "plugged" or blocked, sometimes accompanied by a feeling of fluid or debris in the canal
• Lymph node tenderness: The lymph nodes in front of or below the ear may become swollen and tender

Diagnosis

A GP or audiologist diagnoses swimmer's ear through clinical examination using an otoscope — a handheld instrument with a light and magnifying lens. The examination typically reveals a red, swollen ear canal, often containing discharge or debris. In mild cases, the eardrum is visible and appears normal. In more severe infections, the canal may be so oedematous (swollen) that the eardrum cannot be visualised — in such cases, the clinician will need to treat the infection before reassessing the eardrum to rule out other conditions. If fungal otitis externa is suspected, examination may reveal characteristic hyphae (thread-like fungal filaments) or spores. A swab for culture and sensitivity may be taken if the infection does not respond to initial treatment, to identify the causative organism and guide antibiotic or antifungal choice.

Treatment

The vast majority of swimmer's ear cases are treated effectively with topical ear drops, without the need for oral antibiotics. Treatment aims to eliminate the infection, reduce inflammation, relieve pain, and restore the ear canal's natural protective environment.

Antibiotic and Steroid Ear Drops

The mainstay of treatment for bacterial otitis externa is a combination of topical antibiotic and corticosteroid ear drops. Commonly prescribed formulations in the UK include ciprofloxacin with dexamethasone, and gentamicin with hydrocortisone. The antibiotic targets the bacterial infection while the corticosteroid reduces swelling and pain. Drops are typically used for 7 to 10 days, and it is important to complete the full course even if symptoms improve earlier. When applying drops, lie on the unaffected side, instil the drops, and remain in position for several minutes to allow the medication to reach the full length of the canal.

Acetic Acid Drops (EarCalm)

For mild cases — particularly those caught early — acetic acid ear drops such as EarCalm, available over the counter from UK pharmacies without a prescription, can be effective. Acetic acid works by restoring the ear canal's natural acidic pH, creating an environment hostile to bacteria and fungi. It is also useful as a preventive measure after swimming (discussed below). If symptoms do not improve within 48 hours of using acetic acid drops, or if pain is significant, GP assessment for prescription antibiotic drops is recommended.

Antifungal Treatment for Otomycosis

If fungal otitis externa is diagnosed, treatment requires antifungal medication rather than antibiotics. Topical clotrimazole solution or cream is the most commonly used first-line antifungal in the UK. Treatment duration is typically longer than for bacterial infections — often two to three weeks — and recurrence is more common. Microsuction or careful aural toilet (cleaning of the ear canal by a specialist) to remove fungal debris can significantly improve treatment outcomes and is available at many ear wax removal clinics and ENT departments across the UK.

Ear Wick

If the ear canal is significantly swollen — to the point where drops cannot penetrate to the infected area — a clinician may insert an ear wick (a small, expandable sponge) into the canal. Drops are then applied to the wick, which absorbs them and delivers the medication directly to the swollen canal walls. The wick is usually removed or falls out on its own after 24 to 48 hours as the swelling subsides.

Oral Antibiotics

Oral (systemic) antibiotics are rarely needed for uncomplicated otitis externa. They may be prescribed if the infection has spread beyond the ear canal — for example, to the surrounding soft tissues (cellulitis) — or in patients who are immunocompromised. Flucloxacillin or ciprofloxacin are the most commonly used oral antibiotics in this context.

Home Care During Treatment

Alongside prescribed medication, several home care measures can support recovery:

• Keep the affected ear completely dry throughout treatment — avoid swimming, and use cotton wool coated with petroleum jelly (Vaseline) when showering to keep water out
• Take paracetamol or ibuprofen for pain relief as needed
• Remove hearing aids from the affected ear until the infection has cleared
• Do not insert anything into the ear canal, including cotton buds
• Apply a warm (not hot) flannel against the ear for comfort if pain is significant

Prevention Strategies

For people who are prone to recurrent swimmer's ear — including regular swimmers, hearing aid users, and those with eczema or other skin conditions affecting the ear — prevention is far better than repeated courses of treatment. The following strategies are recommended by the NHS and NICE:

• Keep ears dry: After swimming, showering, or bathing, tilt the head to each side to allow water to drain from each ear canal. Gently dry the outer ear with a soft towel. A hair dryer on the lowest heat setting held at arm's length can help evaporate residual moisture — but never insert the dryer nozzle into the ear canal
• Use well-fitted swim plugs: Custom-moulded or properly fitting silicone swim plugs keep water out of the ear canal during swimming and water sports. A neoprene headband worn over the ears provides additional protection, particularly for children
• Avoid cotton buds: Do not insert cotton buds, fingers, or any objects into the ear canal. The ear canal is self-cleaning — wax naturally migrates outwards. Cotton buds push wax deeper, remove the protective cerumen layer, and can scratch the canal skin
• Acetic acid drops after swimming: A 2% acetic acid solution (or a home-made mixture of equal parts white vinegar and cooled boiled water) applied after swimming helps restore the ear canal's natural acidity and prevent microbial colonisation. Commercial preparations such as EarCalm can be used for this purpose
• Manage underlying skin conditions: If you have eczema, psoriasis, or dermatitis affecting the ears, work with your GP or dermatologist to keep the condition well controlled, as flare-ups increase vulnerability to otitis externa

Hearing Aids and Otitis Externa

People who wear hearing aids face a higher risk of developing otitis externa due to the occlusive nature of ear moulds and in-ear devices. The BSA recommends several measures to reduce this risk:

• Clean hearing aid moulds and domes regularly according to the manufacturer's instructions — daily wiping and weekly deep cleaning is a good routine
• Allow the ears to "breathe" by removing hearing aids for periods during the day, particularly in warm weather or after physical activity
• Ensure the hearing aids fit correctly — ill-fitting moulds can cause pressure points and skin irritation that predispose to infection. If your moulds are causing discomfort, contact your audiologist for adjustment
• If you develop signs of otitis externa (pain, itching, discharge), remove the hearing aid from the affected ear and seek GP advice promptly. Continuing to wear a hearing aid in an infected ear can worsen the condition and delay healing
• Consider having your ears checked by a hearing care professional before the summer if you plan to swim regularly, so any early signs of canal problems can be addressed

Malignant (Necrotising) Otitis Externa

While the vast majority of swimmer's ear cases are straightforward and resolve with topical treatment, there is one serious complication that warrants awareness: malignant otitis externa, also called necrotising otitis externa. Despite its alarming name, this is not a cancer — it is a severe, potentially life-threatening infection that spreads from the ear canal into the surrounding bone (the temporal bone) and soft tissues.

Malignant otitis externa occurs almost exclusively in specific risk groups:

• People with diabetes — particularly those with poorly controlled blood sugar, who account for the majority of UK cases
• Immunocompromised individuals — including those on chemotherapy, long-term steroids, or immunosuppressive medications, and people living with HIV/AIDS
• Older adults — who may have age-related immune decline alongside diabetes or other co-morbidities

Warning signs include severe, deep ear pain that is disproportionate to the visible infection, pain that persists or worsens despite appropriate topical treatment, fever, headache, and granulation tissue visible in the floor of the ear canal. If the infection spreads, it can involve the cranial nerves — most commonly causing facial nerve palsy (weakness of one side of the face). Malignant otitis externa requires urgent hospital admission, intravenous antibiotics (typically prolonged courses), imaging (CT or MRI) to assess the extent of bony involvement, and close monitoring by an ENT specialist.

If you have diabetes or a weakened immune system and develop ear pain, discharge, or any symptoms of otitis externa, seek medical advice promptly rather than self-treating, so that any early signs of this serious complication can be detected.

When to Seek Help

Most mild cases of swimmer's ear can be managed with over-the-counter acetic acid drops and good ear care. However, you should see your GP if:

• Ear pain is severe or getting worse despite self-care measures
• There is discharge from the ear — especially if it is yellow, green, or foul-smelling
• Hearing loss develops or worsens
• Symptoms have not improved after 48 hours of using over-the-counter ear drops
• You have recurrent episodes — three or more episodes per year warrant investigation for underlying causes such as skin conditions or canal anatomy

Seek urgent medical attention if you experience severe pain with fever, spreading redness or swelling around the ear, or if you have diabetes or a weakened immune system. These features may indicate malignant otitis externa, which requires hospital assessment and treatment. If you are concerned about any change in your hearing following an ear infection, a hearing test can confirm whether your hearing has returned to normal or whether further investigation is needed.