How do you deduce that a child has an ear infection? I had terrible ones as a young thing (my dad smoked a lot), but my mother didn't always know I had them until they were rather far along. How will I know when my baby has one? What are the symptoms?

Since ear infections are the most common diagnosis in pediatrics, it is worthwhile for a parent to learn to become a Sherlock Holmes, able to notice the clues and suspect an ear infection before it becomes advanced.

First, let's dispatch with a red herring. You've found a clue -- you notice ear pulling in your child under age two what does this tell you? Shockingly, careful studies (e.g. Pediatrics December 1992; 90:1006) have found that 0% of children with ear pulling as the primary sign had ear infections. Even in conjunction with other important clues, such as fever, only 15% of those brought in for ear pulling actually had ear infections. Most commonly, children pull their ears from itching (caused by soap or shampoo in the canal, or by a healing infection), teething, exploration, comfort, or habit. You are now already ahead of the crowd. Ear pulling is one of the most common reasons for pediatric office visits.

Fact: Most ear infections hurt. The pain builds as the pressure in the ear builds, from a dull ache to a sharp stabbing pain. The pressure is relieved intermittently, so the pain comes in waves. The pain is worse at night. In an older child, "My ear hurts!" is the most reliable clue. Most ear infections, however, occur in children under age two. In younger children the best clue is evidence of pain, such as crying or screaming (usually less than half an hour), fussiness or irritability (worse when lying down), or suddenly increased difficulty sleeping, especially at night. They often have no pain the following morning.

Fact: In an ear infection, fluid fills the middle ear. Older children often mention a feeling of fullness or decreased hearing in the affected ear. This is difficult to detect in an infant, but you might notice shaking of the head.

Fact: Only one third to one half of children with an ear infection will develop a fever. Temperatures over 104 occur in fewer than 5% of ear infections. Fevers are more common in infants and toddlers than in older children. By itself, a fever is not a powerful clue - but in conjunction with the clues outlined above, it is quite incriminating indeed (the combination of fever and pain is most often an ear infection in infants and toddlers).

Other Suspects: Don't let other symptoms, such as loose stools or vomiting, throw you off the trail. Ear infections are sometimes accompanied by systemic symptoms.

Accomplices: This job cannot be pulled off alone. Something must plug the eustachian tube for an ear infection to occur. Most commonly an upper respiratory infection is the culprit.