Diagnosis

Your doctor can usually diagnose an ear infection or another condition based on the symptoms you describe and an exam. The doctor will likely use a lighted instrument (an otoscope) to look at the ears, throat and nasal passage. He or she will also likely listen to your child breathe with a stethoscope.

Pneumatic otoscope

An instrument called a pneumatic otoscope is often the only specialized tool a doctor needs to diagnose an ear infection. This instrument enables the doctor to look in the ear and judge whether there is fluid behind the eardrum. With the pneumatic otoscope, the doctor gently puffs air against the eardrum. Normally, this puff of air would cause the eardrum to move. If the middle ear is filled with fluid, your doctor will observe little to no movement of the eardrum.

Additional tests

Your doctor may perform other tests if there is any doubt about a diagnosis, if the condition hasn't responded to previous treatments, or if there are other long-term or serious problems.

• Tympanometry. This test measures the movement of the eardrum. The device, which seals off the ear canal, adjusts air pressure in the canal, which causes the eardrum to move. The device measures how well the eardrum moves and provides an indirect measure of pressure within the middle ear.
• Acoustic reflectometry. This test measures how much sound is reflected back from the eardrum — an indirect measure of fluids in the middle ear. Normally, the eardrum absorbs most of the sound. However, the more pressure there is from fluid in the middle ear, the more sound the eardrum will reflect.
• Tympanocentesis. Rarely, a doctor may use a tiny tube that pierces the eardrum to drain fluid from the middle ear — a procedure called tympanocentesis. The fluid is tested for viruses and bacteria. This can be helpful if an infection hasn't responded well to previous treatments.
• Other tests. If your child has had multiple ear infections or fluid buildup in the middle ear, your doctor may refer you to a hearing specialist (audiologist), speech therapist or developmental therapist for tests of hearing, speech skills, language comprehension or developmental abilities.

What a diagnosis means

• Acute otitis media. The diagnosis of "ear infection" is generally shorthand for acute otitis media. Your doctor likely makes this diagnosis if he or she sees signs of fluid in the middle ear, if there are signs or symptoms of an infection, and if symptoms started relatively suddenly.
• Otitis media with effusion. If the diagnosis is otitis media with effusion, the doctor has found evidence of fluid in the middle ear, but there are presently no signs or symptoms of infection.
• Chronic suppurative otitis media. If the doctor makes a diagnosis of chronic suppurative otitis media, he or she has found that a long-term ear infection resulted in tearing of the eardrum. This is usually associated with pus draining from the ear.