My 8-year-old son, Gerald, hates to visit the dentist. He likes the dentist himself well enough, but the chair, the bright light shining in his face and the metal equipment scraping away at his teeth combine to make him extremely apprehensive.

On our most recent visit, though, I was the one who left feeling anxious. A member of our dentist's staff left my son's Social Security number out for all to see, leaving him vulnerable to identity theft.

How real is the threat for an 8-year-old? About 5 percent of identity-theft complaints to the Federal Trade Commission in 2005 involved victims who were 18 or younger. A report by the Identity Theft Resource Center found that more than half of child identity-theft victims surveyed became victims at age 5 or younger.

I became alarmed about exposing Gerald's information when I walked up to the dentist's front desk to schedule my son's next appointment. The office manager had stepped away for a moment, but Gerald's folder was lying open on her desk.

The waiting room was busy, and anyone who stopped at the desk could have viewed my son's personal information — his name, address, phone number, date of birth and Social Security number. My husband's SSN and health-insurance account information were also available to anybody who would reach over the counter and flip through Gerald's file.

Years ago, I wouldn't have been concerned at all about others viewing our SSNs. Back then, I didn't know identity thieves use others' sensitive personal information to open fraudulent credit accounts, or steal from existing financial accounts. I later learned that more-insidious thieves use SSNs and other personal information to obtain government documents, such as driver's licenses, that let them pose as their victims in order to commit crimes or dodge the law.

Frightening enough, but identity theft can be much more damaging to a child — and because so few parents think their child's data can or would be compromised, they're often careless about guarding it. Generally, parents and child identity-theft victims don't realize a crime has been committed until the kids grow older and try to obtain credit on their own. Then they, and their parents, must deal with hours of paperwork trying to restore the child's good name.

Family members are often the perpetrators of child identity theft. Children are victimized by relatives for a number of reasons: Some family members behave badly with credit and see a child's SSN as a chance for a clean slate; while others are unable to obtain a job because of a past criminal history or because they're illegal immigrants, and use a child's legal SSN as a ticket to employment.

As I became more educated about the dangers of disclosing my son's sensitive personal information, I began to take steps to protect him from identity theft. These days, before divulging Gerald's SSN or providing copies of his birth certificate, I grill the person asking for it why such information is needed, and how it would be protected. Unless the government's involved — as it is with public-school records or our tax returns, for instance — I refuse to provide it.

Gerald's Social Security card and copies of his birth certificate are kept locked away with other sensitive family documents in our firebox. When he's old enough to carry a wallet, I won't let him carry his SSN card in it.

I also look for signs that Gerald's information may have been stolen. Offers of credit in the mail generally don't raise red flags because my son shares a name with his father and grandfather, but I keep an eye out for offers with his middle initial, which is different from theirs.

Finally, an easy way to discover if a child has become a victim of identity theft is to check with the three major credit-reporting companies — Equifax, Experian and TransUnion — to see if he actually has a credit report. Generally, the bureaus don't keep files on minors — if your kid has one, it's likely fraud has been committed. For security reasons, parents who want to check on credit reports for children under age 13 must do so by mail. (Parents can get one free report of their own from each of the Big Three per year at AnnualCreditReport.com.)

When the dentist's office manager returned to her desk with a smile, I asked to speak with her privately and made my concerns known. She was embarrassed and apologetic. For my part, I'm even more diligent about guarding Gerald's SSN and other sensitive information. I know the odds are slim that one of the other moms in the waiting room would actually steal Gerald's data. But he might not always be so lucky.