Otitis externa (OE) is a type of ear infection - an infection of the ear canal, sometimes called 'swimmer’s ear'. Because the canal is dark and warm, it can easily get infected with bacteria and fungus. Usually the entire canal is involved, but a external auditory canal furuncle can be considered a localized form of OE. Diffuse OE is typically a bacterial infection, the most common pathogens being Pseudomonas, Staphylococci, and Proteus, but fungi may also be involved (most commonly Aspergillus and Candida). OE can spread to affect surrounding tissues. OE is different from the kind of infection you get in the middle part of your ear. That kind of infection is called otitis media. Several things can make OE more likely, including the following:

• If you swim or shower a lot, too much water can get into your ears, removing the protective ear wax or remaining in the canal. The water may introduce organisms and makes it easier for germs and fungus to grow in the moist environment.
• Cleaning your ears can remove the protective wax layer and lead to infection.
• If you injure the skin in the ear canal by putting your finger or some object in your ear, an infection can develop in the canal.
• Skin conditions such as psoriasis that occur in other parts of the body can also occur in the ear canal and cause OE.

Your ear might itch, or even hurt very badly. The pain might get worse when your ear moves while you're chewing. The ear might feel plugged up. You might not be able to hear as well. Your ears might drain. See your doctor if any of these things happen. None of these things should last if you get treated.

Your doctor will inspect your ear and remove any drainage, pus and possibly wax. They will also make sure that the infection is not deeper. Most OE infections can be treated with ear drops, but sometimes pills are needed.
Your doctor will tell you how, how long and how often to use your ear drops. Warm the bottle in your hands before putting the drops in your ear. Using warm ear drops may keep you from getting dizzy when the drops go in. Sometimes cotton is inserted afterwards to hold the medication in.

While OE can be hard to treat, there are things you can do to help, as well as prevent recurrence.

• Keep your ear as dry as possible for 7 to 10 days. Take baths instead of showers. Try to keep water out of your ears when you wash your hair. Don't swim or play other water sports. If you're on a swim team, ask your doctor before you return to swimming.
• Don't put anything except the prescribed medicine in your ears. Scratching and rubbing will only make OE worse.
• Never put anything in the ear canal (cotton swabs, paper clips, liquids or sprays, or even your finger). This can damage or irritate the skin. If your ears itch a lot, see your doctor. Don't use earplugs. They can irritate the ear canal.
• Leave ear wax alone. If you think your ear wax affects your hearing, see your doctor to be sure there's no other cause.
• Keep your ears as dry as possible. Use a towel to dry your ears well after swimming or showering. Help the water run out of your ears by turning your head to each side and pulling the earlobe in different directions. A hair dryer set on the lowest heat and speed can also help to dry ears. Be sure to hold it several inches from your ear. If you swim or surf, use a bathing cap or wet suit hood to keep water out of your ears.

Symptoms are usually much better in 3 days and should be completely gone in 10 days. If you're not better by then, see your doctor.

Conventional therapy may consist of combination antibiotic/steroid drops. Sometimes a wick is placed in the canal. The ear wick is typically a dried sponge which is inserted into the canal. It helps wick ear drops along the canal, holds the solution in contact with the skin of the canal, and also applies pressure to the canal skin. Wicks are removed at 2 days, and can be replaced then if necessary.