Your child is fussy, has difficulty sleeping, and you are wondering what is wrong. Is it just that cold or is something else the matter? Then she tugs on her ear. These are the telltale signs of an ear infection. Most parents of infants and toddlers are all too familiar with them.

Ear infections, known clinically as otitis media, are one of the most common medical conditions affecting young children, said Janet W. Dellinger, MD, of Memphis Pediatrics. Seventy-five percent of children experience at least one ear infection by their third birthday, according to the National Institute on Deafness and Other Communication Disorders. Almost half of these children will have three or more ear infections during their first 3 years.

An ear infection is an infection or inflammation of the middle ear. It starts when fluid gets trapped in the ear usually during a cold or other upper respiratory infection, Dr. Dellinger said. The trapped fluid provides a perfect breeding ground for bacteria or viruses to grow.

Symptoms of an ear infection may include fussiness, difficulty sleeping, discomfort during bottle feeding, and tugging of the affected ear, Dellinger said. Otitis media is often difficult to detect because most young children cannot tell someone what is bothering them. Some children are asymptomatic and we diagnose an ear infection during a well baby visit, Dr. Dellinger said.

Doctors diagnose ear infections by looking in the ear with a special device called an otoscope. Redness, inflammation, and the presence of pus indicate an ear infection. 

But doctors cant tell by looking through the otoscope whether the cause is bacterial or viral. In children younger than 2, most pediatricians will treat the infection as bacterial and prescribe an antibiotic (anti-bacterial) drug.

We usually assume its bacterial and treat it as such because we have such aggressive bacteria here in the United States, Dr. Dellinger said.

Some parents are concerned about their children developing antibiotic resistance if they are given antibiotics too often. If parents do have this concern and their children are older than 2 and otherwise healthy, pediatricians may wait to see if the infection clears on its own. 

The pain caused by infection may be treated with pain relievers such as Tylenol and Advil. (Parents should not give their children aspirin because it has been associated with Reyes syndrome.)

If ear infections are resistant to treatment or are unusually persistent, pediatricians will often recommend that special tubes be inserted in the childs ear to ventilate the ear and prevent fluid from becoming trapped. This operation, called a myringotomy, can usually be done on an outpatient basis by a surgeon. While the child is asleep under anesthesia, a small tube is placed into the opening in the eardrum. The tube normally stays in the eardrum for 6 to 12 months, after which time it usually comes out spontaneously.

If left untreated, ear infections can spread into the bones behind the ear (mastoiditis) and even into the lining of the brain (meningitis), which is potentially fatal. Persistent fluid in the ear and chronic infections may also lead to hearing problems and speech development delays. 

Young children are vulnerable to ear infections because their immune systems are not fully developed. Children in group day care settings are more at risk because they are in regular close contact with other young children. Another reason ear infections affect young children so frequently has to do with the child's eustachian tubes. The eustachian tube is a small passageway that connects the upper part of the throat to the middle ear. It is shorter and straighter in the child than in the adult, making it easier for fluid to get trapped. Around age 2 the tube begins to grow and become more slanted so fluid can drain from the tube. The incidence of ear infections drops after age 2, Dr. Dellinger said.

Parents can take steps to prevent ear infections, Dr. Dellinger said. They should keep their children away from secondhand smoke, breastfeed their children if possible, and elevate their heads when giving them a bottle. Parents should also keep children away from other sick children whenever possible.

The development of the Haemophilus influenzae (Hib) vaccine and pneumococcal vaccine (Prevnar), which are both part of childrens regular immunization schedule, have prevented ear infections caused by those types of bacteria. But additional vaccines are needed, Dr. Dellinger said.

If we could get a vaccine to target some of the other bacterial causes that would make a huge difference, Dr. Dellinger said.