Section 19. Ear, Nose, and Throat Disorders

Chapter 220. Middle and Inner Ear Disorders

Topics: Introduction | Perforation of the Eardrum | Barotrauma | Infectious Myringitis | Acute Otitis Media | Serous Otitis Media | Chronic Otitis Media | Mastoiditis | Meniere's Disease | Vestibular Neuronitis | Temporal Bone Fracture | Auditory Nerve Tumors | Tinnitus

Serous Otitis Media

Serous otitis media is an accumulation of fluid in the middle ear.

Serous (secretory) otitis media can develop from acute otitis media that has not completely cleared or from a blocked eustachian tube. Allergies are a common cause of eustachian tube blockage. Serous otitis media can occur at any age but is particularly common in children (see Section 23, Chapter 276).

Normally, pressure in the middle ear is equalized 3 or 4 times a minute as the eustachian tube opens during swallowing. If the eustachian tube is blocked, pressure in the middle ear tends to decrease as oxygen is absorbed into the bloodstream from the middle ear. As the pressure decreases, fluid accumulates in the middle ear, reducing the eardrum's ability to move. Usually, although not always, the fluid contains some bacteria, but symptoms of active infection (such as redness, pain, and pus) are rare. People usually notice a fullness in the affected ear and may hear a popping or crackling sound when they swallow. Some hearing loss commonly develops.

A doctor examines the ear to make the diagnosis. Tympanometry (see Section 19, Chapter 218) helps diagnose the presence of fluid in the middle ear.

Treatment

Decongestants, such as phenylephrine and ephedrine, and, in people with allergies, antihistamines, can be taken to reduce congestion and help open the eustachian tube. Although most people are treated with antibiotics in the United States, they usually are not necessary. Low pressure in the middle ear can be temporarily increased by forcing air past the blockage in the eustachian tube. To do this, the person breathes out with the mouth closed and the nostrils pinched shut.

If symptoms become chronic (lasting more than 3 months), a doctor may perform a myringotomy, in which an opening is made through the eardrum to allow fluid to drain from the middle ear. A tiny drainage tube (tympanostomy tube (see Section 23, Chapter 276)) can be inserted into the opening in the eardrum to help fluid drain and allow air to enter the middle ear.