Otitis Externa: Swimmer’s Ear Causes and the Drops That Actually Work

Otitis externa, commonly called swimmer’s ear, isn’t just an annoyance after a swim-it’s a real infection that can turn a relaxing day at the pool into days of pain and discomfort. Unlike middle ear infections, which happen behind the eardrum, swimmer’s ear affects the skin lining your outer ear canal-the tube that runs from your eardrum to the outside of your head. When this skin gets irritated, wet, or scratched, bacteria or fungi move in and cause trouble. It’s not rare: about 1 in 10 Americans get it every year, according to the CDC. And if you swim often, live in a humid climate, or have diabetes, your risk goes up.

What Causes Swimmer’s Ear?

The outer ear canal is designed to protect itself. It’s slightly acidic-between pH 5.0 and 5.7-which keeps most germs from growing. Earwax, or cerumen, helps by trapping dirt and repelling water. But when that balance breaks down, infection follows.

Swimming is the classic trigger. Water trapped in the ear canal creates a moist environment where bacteria thrive. But you don’t need to swim to get it. Showering, sweating, or even cleaning your ears with cotton swabs can do the same damage. Swabbing pushes wax deeper, scrapes the delicate skin, and removes the natural barrier. That’s why people who clean their ears frequently are more likely to get swimmer’s ear.

There are two main culprits: bacteria and fungi. Pseudomonas aeruginosa is the most common bacterial offender, causing 35-54% of cases. Staphylococcus aureus comes second, responsible for 20-30%. Fungal infections, known as otomycosis, are less common but still make up about 10% of cases-mostly from Aspergillus or Candida species. These fungi love warm, damp places and often show up after antibiotic drops fail to clear a bacterial infection.

People with diabetes or weakened immune systems are at higher risk for severe cases. In rare instances, the infection can spread to the bone around the ear-a condition called malignant otitis externa. It affects only 0.03% of cases but can be life-threatening if not caught early.

How Bad Is It? Symptoms by Severity

Not all cases are the same. Symptoms range from mild irritation to unbearable pain. Doctors classify it in three levels:

• Mild (45% of cases): Itching, slight redness, and a feeling of fullness in the ear. Pain is minimal and gets worse when you tug on the earlobe or press on the bump in front of the ear.
• Moderate (35%): The ear canal starts swelling shut. You might hear muffled sounds. Pain increases, especially when chewing or moving your jaw. Drainage may appear clear or cloudy.
• Severe (20%): The canal is completely blocked by swelling. Pain is intense, sometimes radiating to your neck or face. Fever above 101°F (38.3°C), swollen lymph nodes, and pus are common. This is when you need to see a doctor immediately.

One thing to remember: if you have a perforated eardrum, some ear drops can damage your hearing. Always check with a professional before using anything in your ear if you’ve had ear surgery or tubes.

The Drops That Work: What’s Actually Effective?

Treatment depends on whether it’s bacterial or fungal, and how bad it is. The goal is simple: kill the infection, reduce swelling, and restore the ear’s natural acidity.

For mild cases: Over-the-counter 2% acetic acid with hydrocortisone (sold as VoSoL HC Otic or Swim-Ear) is the first-line choice. It’s cheap-around $15-and works in 85% of cases. Acetic acid restores the ear’s pH, making it hard for bacteria to survive. Hydrocortisone reduces itching and swelling. Many people use it after swimming as a preventive. Studies show it cuts recurrence by 65%.

For moderate to severe cases: Prescription drops like Ciprodex (ciprofloxacin and dexamethasone) are the gold standard. This combo kills bacteria and reduces inflammation in one bottle. Clinical trials show 92% of patients recover within 7 days. It’s more expensive-$147.50 without insurance-but it works faster and more reliably than single-ingredient drops.

Generic alternatives like ofloxacin (OtiRx, approved in March 2023) are also effective. The new extended-release version lasts 24 hours, so you only need one dose a day instead of two. It costs about $45 and has a 94% success rate.

For fungal infections, clotrimazole 1% is the go-to. It works in 93% of cases-far better than acetic acid, which only helps about 78% of fungal cases. If your ear itches like crazy and you see white or black patches inside, it’s likely fungal. Don’t waste time with antibiotic drops-they won’t help.

Stay away from old-school drops like neomycin-polymyxin. They’re cheaper but carry a 5-7% risk of causing allergic skin reactions. Worse, if you have a hole in your eardrum, they can damage your hearing. The FDA warns against them for this reason.

How to Use Ear Drops Correctly (Most People Get It Wrong)

Even the best drops won’t work if you use them wrong. A 2021 study found that 40% of people reduce their own treatment success by applying drops incorrectly.

Here’s how to do it right:

1. Warm the bottle in your hands for 1-2 minutes. Cold drops can make you dizzy.
2. Wipe the outer ear with a dry cloth. Don’t stick anything inside the canal.
3. Lie on your side with the infected ear facing up.
4. Instill the exact number of drops prescribed.
5. Stay in that position for 5 full minutes. This lets the medicine reach deep into the canal.
6. Gently tug on your earlobe to help the drops move deeper.
7. Don’t plug your ear with cotton. It absorbs the medicine.

Many people skip the 5-minute wait. Others use cotton swabs afterward-big mistake. You’re wiping out the medicine you just paid for.

If your ear canal is swollen shut, drops can’t reach the infection. In those cases, a doctor may insert a tiny sponge called an ear wick. It expands with moisture and lets the drops soak in. It’s uncomfortable, but it’s necessary. About 65% of patients say it’s worth it.

What Doesn’t Work (And Why You Should Avoid It)

There’s a lot of misinformation out there.

Don’t use hydrogen peroxide. It dries out the skin and can make inflammation worse.

Don’t use vinegar alone. While acetic acid works, plain vinegar is too strong and can burn sensitive skin.

Don’t take oral antibiotics. The American Academy of Otolaryngology says they offer less than 7% extra benefit over topical drops-and they increase side effects like nausea and diarrhea by 15%. For most cases, pills are unnecessary.

Don’t self-diagnose fungal infections. If your symptoms don’t improve in 3 days with antibiotic drops, it might be fungal. But guessing wrong can delay treatment by a week or more.

One study found that 15% of people who tried to treat their own ear infection with OTC drops ended up in the ER because they used the wrong medicine.

Cost, Access, and New Options

Ciprodex is effective but pricey. If cost is an issue, ask your doctor about generic ofloxacin. It’s just as good for most cases and costs a third of the brand name. Some pharmacies offer discount programs-GoodRx can save you $100 or more.

OTC acetic acid drops are great for prevention. Use them after swimming or showering. Just a few drops can keep your ear canal dry and acidic.

New treatments are on the horizon. Stanford University is testing microbiome-based drops that restore healthy ear bacteria instead of killing everything. Early results look promising. But for now, the proven options are still the best.

When to See a Doctor

You don’t need to rush to the clinic for mild itching. But call your doctor if:

• Pain gets worse after 2 days of treatment
• You have a fever or swollen lymph nodes
• Your hearing feels muffled
• You have diabetes and symptoms don’t improve in 48 hours
• You’ve had ear surgery or tubes

Telemedicine is now reliable for diagnosing swimmer’s ear. Mayo Clinic’s 2022 pilot study showed 88% accuracy using video calls. If you’re in a rural area or can’t get an appointment, a virtual visit might be your best first step.

Prevention: How to Avoid It Next Time

The best treatment is no treatment at all. Here’s how to prevent swimmer’s ear:

• Use acetic acid drops after swimming or showering.
• Don’t insert cotton swabs, bobby pins, or fingers into your ear.
• Dry your ears with a towel after water exposure-tilt your head and gently pull the earlobe to help water drain.
• Wear a swim cap or earplugs if you swim often.
• If you have diabetes, keep your blood sugar under control. It’s one of the biggest risk factors.

Swimmer’s ear is common, but it’s not inevitable. With the right knowledge and care, you can enjoy the water without fear.