An outer ear infection, often called swimmer’s ear, is treated with prescription eardrops that you apply directly into the ear canal for 7 to 10 days. Most cases clear up within that window when treated properly, and oral antibiotics aren’t needed unless the infection has spread beyond the ear canal.
What Causes an Outer Ear Infection
Outer ear infections develop when bacteria or fungi multiply in the ear canal, usually after moisture gets trapped inside. Swimming is the most common trigger, but anything that disrupts the canal’s natural protective lining can set the stage: cotton swabs, earbuds, hearing aids, or even scratching an itch with a fingernail. The damaged skin lets bacteria take hold.
Pseudomonas species cause about 38% of all outer ear infections, making them the single most common culprit. Staphylococcus bacteria account for another large share. Fungal infections are less common overall, but when they do occur, Aspergillus is responsible 80 to 90% of the time. Fungal cases tend to cause more itching than pain and sometimes produce a thick, dark discharge.
Topical Eardrops Are the First-Line Treatment
The standard treatment is a topical eardrop applied directly to the infected canal. Several FDA-approved options exist, and your doctor will choose one based on the severity of your infection and whether your eardrum is intact. The main categories include antibiotic drops (like those containing ciprofloxacin or ofloxacin), antibiotic-steroid combination drops that add a small amount of anti-inflammatory medication, and acidifying drops that use acetic acid to create an environment hostile to bacteria.
You might assume that combination drops with a steroid would work better because they reduce swelling, but the clinical evidence is surprisingly mixed. A Cochrane review of four studies involving 475 people found low-certainty evidence that adding a steroid to a topical antibiotic made little or no difference in clearing the infection at one to two weeks. Some evidence even suggested that antibiotics alone may perform slightly better at resolving discharge. In practice, your doctor may still prescribe a combination drop if swelling is significant enough to block the canal, since reducing inflammation helps the antibiotic reach deeper tissue.
One important safety note: if you have a perforated eardrum or ear tubes, certain drops containing aminoglycoside antibiotics (like neomycin) or polymyxin can damage your hearing. Make sure your doctor knows about any history of eardrum problems before prescribing drops.
How to Apply Eardrops Correctly
Getting the drops to actually reach the infected area matters more than most people realize. A poorly applied drop can sit at the canal entrance and never contact the infection. Here’s the technique that works:
- Tilt your head so the affected ear faces the ceiling. This lets gravity pull the liquid down into the canal.
- Place the dropper at the canal opening without touching your ear with the tip, which would contaminate the bottle.
- Apply the prescribed number of drops, then gently press the small flap of cartilage at the front of your ear canal (called the tragus) a few times. This pumps the drops deeper inside.
- Stay tilted briefly, though gravity and gentle pressure are usually enough. You don’t need to lie on your side for minutes.
If swelling has narrowed the canal so much that drops can’t get through, your doctor may place a small sponge wick into the canal. You apply the drops onto the wick, which absorbs and delivers the medication past the blockage. The wick typically falls out on its own as swelling decreases.
How Long Treatment Takes
Most outer ear infections clear up within 7 to 10 days of starting treatment. You should use the drops for at least 7 full days even if symptoms improve earlier, because stopping too soon invites the infection to return. More severe infections may require 10 to 14 days of treatment.
If your symptoms haven’t improved after a full week of drops, contact your doctor. You can continue using the drops for up to an additional 7 days while your doctor reassesses, but persistent symptoms sometimes signal a fungal infection, a resistant bacterial strain, or an underlying issue like a skin condition in the ear canal that needs different treatment.
Managing Pain During Recovery
Outer ear infections can be surprisingly painful. The ear canal is lined with thin, sensitive skin stretched over bone, so even mild swelling creates intense pressure. Over-the-counter pain relievers like ibuprofen or acetaminophen help take the edge off while the drops do their work. The worst pain usually improves within 24 to 48 hours of starting treatment as the infection begins to respond.
Keeping the ear dry is just as important as taking the drops. Avoid submerging your head when bathing, and skip swimming entirely for at least 7 to 10 days. Some doctors allow competitive swimmers to return after 2 to 3 days of treatment if all pain has resolved, but only with well-fitting earplugs. For most people, waiting until the full course of treatment is finished is the safer approach.
When an Outer Ear Infection Becomes Serious
In rare cases, an outer ear infection can spread from the skin of the ear canal into the surrounding bone, a condition called necrotizing (or malignant) otitis externa. This is not cancer despite the name. It’s a deep, aggressive bone infection that requires urgent treatment.
People with diabetes, weakened immune systems, or those undergoing chemotherapy are at highest risk. Warning signs include pain that is far out of proportion to what the ear looks like, pain that worsens despite several days of topical treatment, drainage that won’t stop, or tenderness in the bone behind the ear. Some people develop facial drooping or other nerve-related symptoms on the affected side if the infection reaches the skull base. Diagnosis typically requires a CT or MRI scan, and treatment involves weeks of systemic antibiotics rather than drops alone.
Preventing Future Infections
If you swim regularly or have had swimmer’s ear before, a simple homemade preventive solution can reduce your risk. Mix equal parts white vinegar and rubbing alcohol. After swimming, pour about 1 teaspoon (5 milliliters) into each ear, let it sit for a moment, then tilt your head to drain it out. The alcohol helps evaporate trapped water while the vinegar creates an acidic environment that discourages bacterial growth. Do not use this if you have a perforated eardrum.
Beyond the drops, the best prevention is mechanical: keep your ear canals dry and undamaged. Shake water out of your ears after swimming, dry them gently with a towel, and resist the urge to clean inside the canal with cotton swabs. The ear canal is self-cleaning. Earwax is part of its defense system, trapping debris and maintaining an acidic barrier. Removing it aggressively strips that protection and creates the micro-abrasions where infections start.