Is it good to get sick?
Robert P. Lindeman, MD, PhD
Natick Pediatrics, PC

I saw a 1 month-old girl for a well-child visit. Her mother would be returning to her job in two months, and would be placing the baby in childcare. The mother wanted my opinion of the various childcare options she was considering. I told her I preferred situations with smaller numbers of children, since fewer children means less chance for the baby to catch a virus. The mother replied "But I heard it was good to get sick! Doesn’t it boost the baby’s immune system?"

I hear this story frequently. Another version suggests that children who get sick in the first year of life are less likely to get asthma and other allergic diseases. Still another version states that babies are born with weak immune systems that need to be primed, or kick-started.

Babies get sick. This is a fact of life. The overwhelming majority of the time, the baby weathers her first cold better than her parents do! But colds are never beneficial. It is never a good thing for your baby to get sick!

Catch ‘em now, won’t catch ‘em later?
One popular myth says that if a baby catches a lot of colds early, he won’t get sick as often later. Unfortunately, this is not true. There are over 100 different varieties of the rhinovirus, one of the viruses responsible for the common cold. A baby in childcare is likely to catch between 8 and 12 colds in a year. Assuming the child really gets sick that often, he would be in fourth grade before he caught every rhinovirus. And that’s only the rhinoviruses! There are about 100 other types of virus that cause the common cold. The unlucky child who catches all of them, and at the same pace as an infant in daycare, would finally be through with them no earlier than Spring break of his junior year in college.

Of course, there are other germs out there besides the viruses that cause colds. There are plenty of microbes in the world and a whole lifetime to catch them. Getting sick early does not speed the process.

Not sick enough?
Over the last several hundred years, the world has seen a sharp increase in the incidence of asthma and auto-immune diseases such as juvenile diabetes. At the same time, the incidence of various infectious diseases such as typhus and diphtheria have declined dramatically (or, as with small-pox, disappeared entirely). A possible explanation, called "the hygiene hypothesis" seeks to link the two phenomena. In a nutshell, the hygiene hypothesis states that we are endowed with an immune system that is designed "for battle". When there are no more enemies left to fight (like small-pox), the immune system must fight something, so it turns against the human body, giving rise to asthma and other allergic and auto-immune diseases.

There is a smaller body of evidence suggesting that getting colds early protects against asthma. Unfortunately, there is an equal or larger body of evidence suggesting that some viruses caught during infancy can actually cause asthma. If mother or father has asthma or allergies, I certainly don’t recommend that they purposefully expose their infant to cold viruses!

The solution to the problem posed by the hygiene hypothesis is not to expose our infants to more cold viruses in their first year. The solution is for all of us to move to the country, live amongst the livestock, forego indoor plumbing, and forget about vaccines and antibiotics. Though some of us may find this idea attractive, it presents logistical problems for all 300 million Americans to do likewise.

Getting the immune system in shape
I hear a lot of confusion and mythology having to do with the infant immune system and what it can and cannot handle. Many people believe that infants are born with weak immune systems that must be protected from all outside influences. According to one common misconception, the infant’s immune system is too weak to receive a Hepatitis B vaccine on the day of birth. Others believe that one should bring a newborn out in public because her immature immune system cannot handle the germs out in the world.

The truth is that a normal infant is born with a fully-functional, multi-pronged, ready and able immune system. It does not need to be primed or tested. It can be neither weakened nor overwhelmed by newborn vaccinations. It is capable of fighting off viral infections. It does not need to be "boosted" by anything.

So why isn’t it good for the baby to get sick?
While the baby is born with a mature immune system, the same cannot be said for other parts of the baby’s body, particularly her nose. Baby noses are very small and very floppy. It is very easy for them to get plugged with mucus. When this happens, the baby cannot do either of the two things that adults can do: clear her throat or blow her nose. Even after the baby’s immune system has annihilated the virus that caused the cold, the residual mucus hangs around in the back of the baby’s nose and throat for a few weeks. It can often interfere with the baby’s ability to drink or to sleep. Fluids and sleep are the two hinges on which all of pediatrics swings. Anyone who has had an infant with a cold can appreciate this.

Finally, it needs to be said, colds are contagious. Babies catch colds from other people who already have colds, frequently from other babies who have colds. Very often, the baby catches a cold from another baby in childcare. Since sick babies should not be brought to childcare, a working parent must miss work. For the parents, as well as for the babies, it is not good for the baby to get sick.

For more information about Natick Pediatrics, or to talk to the doctor, please call the office at (508) 655-9699.

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Medical Office Building
MetroWest Medical Center
Leonard Morse Campus
67 Union Street, Suite 305
South Natick, MA 01760

(508) 655-9699
(508) 655-2984 fax

Posted: November 23, 2004

©2004. Robert P. Lindeman, Natick Pediatrics. All rights reserved.