Why are some diseases or illnesses more common among children?

Chicken Pox, Impetigo, Conjunctivitis, the list goes on. Is it just because they are smaller, and have underdeveloped immune systems? Are children exposed to different pathogens than adults?

I don’t believe children are more susceptible to these diseases; I think it’s due to the fact that we are children before we are adults. The diseases get to us as children because that’s what we are when we’re first exposed to them. And for many of the diseases, we are subsequently immune for life, so fewer adults get them. Plus, don’t forget that kids spend a lot of time among large numbers of other kids, who have the same risk factors. And they spend much of their time putting things into their mouths, wiping their noses on things, and seemingly going out of their way to spread germs as quickly as possible.

Adults can and do get chicken Pox, and IIRC it can be lethal in some cases. People even have Chicken Pox “parties” so that their kids get infected earlier rather than later. This seems to be almost common knowledge. Can all the diseases/illnesses that children commonly get be contracted by adults?

Our immune systems build immunity through exposure to infectious disease. It takes an exposure for the immune system to learn what the disease is and how to fight it. In that time, the disease has usually gotten a foothold and made the person ill. After the disease has been defeated, antibodies, which are kind of a specialized red flag that attach themselves to germs and call in the Marines, remain in the system, forever floating around waiting for the disease to present itself again.

This is why vaccines are so wonderful. They cause the immune system to generate antibodies without the infection that makes people so sick.

The reason kids get sick more often and with more diseases than adults is because their immune systems haven’t been exposed to all the different diseases around. Chickenpox, for instance, is extremely infectious, so when it shows up in a population, its very likely to hit every single person who’s never encountered it before.

There’s a virus out there called roseola or sixth virus (as in, it’s the sixth most prevalent childhood disease) that’s actually related to the herpes simplex virus. A friend of mine has a son who was immuno-compromised for a couple of years with a blood and gastro-immuno disorder. She managed to keep him so successfully sequestered from other sick children (because what made them sick could have killed him) that he came down with roseola when he was six, instead of when he was two or three, like most kids. And now he’s immune to it and probably will be for the rest of his life.

What others have said about Chicken Pox is true. Impetigo, and Conjunctivitis are more common in children because children touch each other. Conjunctivitis, or Pink Eye, can be caused by a number of bacteria, like Staph or Strep. Child rubs eye, touches other child, other child rubs eye. Impetigo is also caused by various bacteria. Staph and Strep being the most common. Anyone, child or adult can contract either of these.

The six viral diseases common in childhood are: Rubiola (Measles), Rubella (German Measles), Mumps, ÊVaricella-zoster (Chicken Pox), Fifth Disease, and Roseola.

Other childhood illnesses are often simply not diagnosed in adults. Pertussis (Whooping cough) is a serious illness for children, because their airways are small. The mucus produced can completely block a child’s airway, but an adult just has a bad cold.

Well, and also kids are touching other kids with spitty fingers and such. They’re just little germ warrens for behavioral reasons as well as biological. It’s definitely worth noting that I used to always catch maybe six colds every winter, though elementary, middle, high school, college, grad school… My first year out of grad school, when I was working in a public library which, trust me, is a teeming mass of germs (I’ve caught ringworm and pinkeye, at least) and I didn’t get sick all winter. In fact, I’ve only had maybe three colds or so since I got out of any kind of school. Any “school” environment is a hotbed of disease.