Fighting a foreign invasion


By Dean Rowland

No one likes to have a cold — the runny nose, the sneezing, the sore throat. Adults can expect to get the sniffles, plus a few other minor illnesses, a couple of times a year, but kids will probably suffer a little more.

Kids get sick more frequently than adults because their immune systems are still developing, experts say.

“Human beings live in a world teeming with micro-organisms,” said Dr. Alicia Salyer, a board-certified pediatrician at Palmetto Pediatrics, which has offices in Bluffton and on Hilton Head Island. “We could not survive without a highly effective system of defense.”

The body’s immune system has two distinct components: innate, the defenses we are born with, and adaptive, which strengthens as we’re exposed to more bacteria and viruses.

Skin is the first line of defense in the innate immune system, which is comprised of a variety of cells and enzymes. Phagocytes, or white blood cells, are the first to attack and kill invading bacteria. Antibodies are the key component in the adaptive immune system, which are proteins that recognize foreign bacteria or viruses.

“Antibodies are small Y-shaped proteins that attack a foreign bacteria or virus by binding it and preventing it from damaging cells or stimulating its removal by other parts of the immune system,” said Salyer, who has been at Palmetto Pediatrics for 15 years and also is the mother of twin fifth-graders. “Vaccines work by harnessing the power of our own immune system. When you receive a vaccine, you are exposing your body to either dead or weakened bacteria or virus that can’t multiply or infect your own cells. Your body will develop your own antibodies.”

Even though infants are born with their own innate immune systems, thanks to the antibodies they get from their mothers through pregnancy and breast feeding, they’re on their own after about six months. Just like adults, they’ll be susceptible to the viruses and bacteria that can enter the body through the mouth, eyes, nose and broken skin.

Parents can help their children boost their immune systems by making sure tots get enough sleep, Salyer said, adding that stress can increase vulnerability to infection.

“Sleep needs vary by age,” she said. “Young children need 10 to 12 hours of sleep at night, and school-aged children typically need about 10 hours.”

It’s also important for children to wash their hands often to prevent infection and to eat plenty of fruits and vegetables — but Salyer doesn’t recommend vitamin supplements if kids’ everyday diets offer sufficient nutrients.

For parents who might be wondering if kids who play in the dirt or live in a house with a pet have stronger immune systems than those who don’t, here’s Salyer’s take:

“Kind of. (It’s) a very interesting theory. The hygiene hypothesis is a theory that decreasing infection rates are contributing to increasing allergies and autoimmune diseases. Early life exposure to a variety of microorganism appears to help prevent the development of some illness such as asthma and inflammatory bowel disease.”