Approximately 5% of kids develop a food allergy by age 6, and around 8% of kids of all ages have one. That's a 50% increase since the 1990s.

Shellfish (about 8.4 million kids), milk and peanuts (about 6.2 million kids each), and tree nuts (about 3.9 million kids) are the most common triggers. Eggs, wheat, and finfish are also possible triggers.

In addition, about 40% of kids have multiple food allergies; the same number will experience a severe reaction.

What makes kids vulnerable to these allergies?

A study in JAMA Pediatrics found that a combination of genetic, environmental, microbial (that's the gut biome), and social factors influence the development of food allergies.

For example, kids who have eczema in their first year are three to four times more likely to develop a food allergy. Infants given antibiotics in their first month of life are at increased risk; those exposed in utero or later in infancy have a slightly increased risk.

There are also genetic predispositions, especially if both parents have such allergies.

These risk factors don't mean your child will develop a food allergy, but it's smart to work with your pediatrician to determine if and when you should adopt prevention or control strategies, such as introducing certain foods and getting skin or blood tests.

If your child does have a food allergy, read food labels carefully, help them avoid triggers, and carry a potentially life-saving EpiPen.

For more on kids' health, read my book "YOU: Raising Your Child, the Owner's Manual From First Breath to First Grade."