Unlike past generations, a lot of us probably know (or have) a child with a food allergy, which can make shopping and cooking for kids a real task for worried parents. Now, a new federal report shows that the number of children diagnosed with food allergies has skyrocketed in the past 10 years.

Based on surveys of about 9,500 households, the Centers for Disease Control and Prevention (CDC) found that food allergy diagnosis in kids went up 18% from 1997 to 2007. Now, about 3 million kids and teens (or 4 out of every 100) have food allergies. And kids with a food allergy are as much as two to four times more likely to have asthma, eczema, or other allergies, too.

According to information from another CDC survey on hospital discharges, food allergy-related hospitalizations have gone way up, too — from around 2,600 from 1998 to 2000 to about 9,500 from 2004 to 2006.

But it's hard to tell if the higher numbers of kids diagnosed with food allergies mean that more kids are actually getting food allergies now than before. It could be that parents and doctors are just more educated about and aware of food allergies — and the warning signs — than they were only 10 years ago.

And because the household survey relies on parents' reports (rather than doctors') the results may not be completely accurate — though this study's food allergy rates are similar to what other clinical studies have found.

How Food Allergies Work

With food allergies, the immune system mistakenly believes that something a person ate is harmful. To try to protect the body, the immune system produces certain types of antibodies (called immunoglobulin E, or IgE) that then cause allergy cells in the body (called mast cells) to release chemicals into the bloodstream. Histamine, one of those chemicals, then starts affecting the person's eyes, nose, throat, lungs, skin, or gastrointestinal tract and causing the symptoms of an allergic reaction.

Although different people may react to allergens in different ways, signs of a mild allergic reaction can include:

• a stuffy, runny nose
• sneezing
• mild skin redness
• red bumps (hives) anywhere on the body
• mild swelling
• itchiness
• itchy, watery eyes

Although most allergic reactions aren't serious, some can be life-threatening and require a call to 911 or a trip to the ER right away. Signs of anaphylaxis (a sudden, potentially severe allergic reaction involving various systems in the body) can include:

• difficulty breathing
• tightness in the throat or feeling like the throat or airways are closing
• hoarseness or trouble speaking
• wheezing
• nasal stuffiness or coughing
• nausea, abdominal pain, or vomiting
• fast heartbeat or pulse
• skin itching, tingling, redness, or swelling

What This Means to You

Eight kinds of foods cause a whopping 90% of all food allergies:

1. milk
2. eggs
3. peanuts (not a true nut, but a legume in the same family as peas and lentils)
4. tree nuts (like almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pistachios, and walnuts)
5. fish
6. shellfish
7. soy
8. wheat

Luckily, most kids with a food allergy will outgrow it. But, unlike allergies to foods like milk and eggs, children generally don't grow out of allergies to peanuts or nuts — they may last a lifetime. So those kids just have to learn to steer clear of foods that could make them sick.

If you're expecting, breastfeeding, or introducing your baby or toddler to foods:

• Talk to your doctor about what the most current food allergy advice specifically means for you. Last winter, the American Academy of Pediatrics (AAP) released a report that made both physicians and parents rethink how and when young kids should be introduced to certain foods to help reduce their risk of developing food allergies, asthma, and allergic rashes. So, discuss your immediate family's history of allergies or asthma and what foods, if any, you might need to avoid.
• Let your doctor know if your breastfed baby seems to have an allergic or hypersensitive reaction to anything you've eaten — consistent spitting up or vomiting, belly pain (lots of gas and/or pulling up the knees in pain), or bloody and/or mucousy stools (poop).
• Talk to your doctor before starting your baby on any solids and, later, before introducing finger or table foods.
• Immediately stop giving a food — and call your doctor — if your child seems to have an allergic reaction to it.

And if your child has already been diagnosed with a food allergy, make sure to:

• Talk to the school (principal, teachers, nurse, cafeteria personnel) about your child's allergy. Give specifics on exactly which kinds of foods and ingredients aren't OK for your child to eat (or even sometimes be around).
• Find about your day care center or school's policy on nuts if your child has a peanut or tree nut allergy. Talk to them about the importance of making sure your child has a safe nut- or peanut-free environment.
• Learn how to read food labels and how to identity which specific ingredients to avoid.
• Keep an antihistamine like diphenhydramine available (which can help with mild allergic reactions).
• Always keep an epinephrine auto-injector with you (it's about the size of a large pen). If your doctor says your child is old enoughand mature enough to use one, make sure he or she always has one on hand or nearby and knows when and how to use it.
• Discuss the food allergy with anyone your child spends time with — family, friends, neighbors, babysitters, child care center employees, teachers, etc.
• Let anyone in charge of watching or teaching your child know about the warning signs of a life-threatening allergic reaction and what to do about it — and fast!