Why do children cough?

June 24, 2010  |  General  |  No Comments

Here’s another excerpt from my new book, How Your Child Heals. It’s from the chapter on symptoms, and it’s about what causes cough.

The hallmark of most respiratory illness, both in children and in adults, is a cough. Coughing is a reflex, one difficult to suppress. You probably know this from the experience of sitting in a quiet setting, such as in a lecture audience or in church, when you have a cold. The urge to cough is nearly impossible to deny, even with intense effort.

The upper and middle portions of the airway, meaning the space between the back of the throat, through the vocal cords, and down to the first branching of the windpipe, are thickly sown with sensors. They are particularly abundant right around the vocal cords and down at the area of the first branching of the windpipe into smaller breathing tubes. If anything touches these sensors the response is a cough. The reason this reflex is so powerful is that nature is fanatic about protecting our airways. We need to breathe every minute, and objects that might block our airways are potentially very dangerous. Since the last line of defense for the lungs is at the windpipe’s first branching, it makes sense that touching that spot provokes a particularly explosive episode of coughing.

Infections of the upper respiratory tract cause the mucous-secreting cells that line the walls to make more mucous, sometimes large amounts of it, and this extra material trips the cough sensors. The upshot is that we cough and cough until the mucus is cleared out of the airway via a mechanism doctors term a productive cough, meaning it produces sputum.

Often, however, a cough is dry–it does not produce any sputum at all because the cause for it is not excess mucous. We term this a nonproductive cough. It often comes in spasms of multiple coughs in succession, followed by a period of relative quiet. This kind of cough is caused by inflammation of the walls of the airway, something respiratory viruses do, and the inflammation triggers the cough sensors. In children, asthma is another common cause because asthma inflames the airways. A nonproductive cough can also happen if we inhale anything that irritates our airways, such as dust, smoke, or a noxious gas.

If a cough is from asthma, we have several medicines to treat that, such as inhaled albuterol. If it’s not asthma, specific treatment is more difficult. There are dozens of products sold over-the-counter as remedies for cough. None of them do much to help it, although they may soothe the back of the throat. The things many of them contain cause unwanted side effects in small children, so most doctors recommend not using them, as does the American Academy of Pediatrics. The last thing we want in a medication for children is something that does not help the situation and may actually cause harm.

We have medicines that really do suppress cough. They do not work on the airway; rather, they work on the brain itself to suppress the cough reflex. Codeine, a narcotic, is the one most commonly used, but there are others. We rarely use these medicines in children, especially small children, because they have significant side effects, primarily drowsiness and altered mental state. Additionally, if a cough is being caused by excess mucous or other material in the airway, we can make the situation worse by blocking the child’s ability to clear the stuff out.

What causes nausea and vomiting?

June 18, 2010  |  General  |  5 Comments

Here’s another excerpt from my new book, How Your Child Heals. It’s from the chapter on symptoms, and it’s about what causes nausea and vomiting.

Most of us are familiar with nausea, that queasy feeling experience has taught us may soon be followed by vomiting. When that happens, we begin to feel a quiver at the base of our tongue and in the back of our throat. At this point we may be able to suppress the feeling enough to keep from vomiting by swallowing a few times or taking some deep breaths. If none of that works, we soon toss whatever is inside our stomach out through our mouths, after which the nausea is typically improved, at least for a short time. If there is nothing in our stomachs, we may still go through the vomiting reflex–the dry heaves.

Vomiting differs from mere spitting up, what parents of a baby often call a wet burp. Vomiting is a very forceful act involving contraction of powerful muscles in the stomach and abdomen. When a baby spits up it is because the muscular tissue at the junction between her stomach and the lower part of her esophagus is too lax to keep the food inside. We call that regurgitation or reflux of stomach contents. An older child or adult with heartburn is experiencing a version of the same thing, only usually the stomach contents do not make it all the way up into the mouth. Spitting up is simply a local event in the lower esophagus, with the stomach contents running back up the wrong way for a moment. In contrast, vomiting is a complex reflex in which several parts of the brain and the digestive system need to communicate with each other and coordinate what they are doing.

Both nausea and vomiting are controlled by a place in the lower part of the brain in the region we call the brain stem. Regulatory centers for many of our basic reflexes, like the one that keeps us breathing, are located nearby. This fact tells us that vomiting is an ancient and primitive reflex that has been with us for a very long time. Doctors are notorious for devising esoteric and fancy names for anatomic places, but this spot in the brain is called by a very practical term–the vomiting center.

Many things can awaken the vomiting center and cause it to do its job. Signals from the higher centers in the brain where we do our thinking can do it. Anyone who has had a queasy thought after seeing something distasteful can attest to this connection. The links between the vomiting center and the parts of the brain that regulate balance are especially close, which is why a ride in a roller coaster or a bumpy airplane can make you throw up. The vomiting center also is sensitive to mechanical pressure on it, so vomiting is a common symptom when people have increased pressure inside their brain.

The vomiting center also quickly responds to a whole host of things it detects in the bloodstream. Many medications have nausea and vomiting as a side effect. This is a particular problem with some of the drugs we use to treat cancer. We even have drugs we can give to provoke vomiting as their intended effect. Changes in the body’s hormones, such as occurs with pregnancy, can activate the center. The majority of woman will have at least some problems with nausea and vomiting when they are pregnant, especially during the early months.

For a parent with a sick child, the most important things that tickle the vomiting center are those that happen in the digestive tract, since many disorders of the stomach and intestines lead to vomiting. There are nerves located throughout the digestive tract, especially in the upper portions of it, which run back to the vomiting center. These even begin in the mouth, which is why a person who gags when the back of the throat is touched may quickly vomit. For some people, even brushing their teeth can bring this on if they are not careful.

For the stomach and small intestines, any inflammation there sends messages back up the neural network to the vomiting center. If the signals are strong enough, the person will vomit. For children, the most common cause of this is a viral infection, the stomach flu. Intestinal nerves are especially sensitive to stretching. This also applies to the nerves that control nausea and vomiting, so a digestive tract that is stretched full of air and food that is not going anywhere can do more than hurt; it is also primed for the vomiting reflex. We know this is so because, in such a situation, often the simple technique of slipping a tube down into the stagnant lake of stuff in the stomach and upper intestines and sucking it back out will relieve a person’s nausea and vomiting.

The vomiting act itself, though it happens quickly, is an intricate series of events. When the vomiting center sends out the go signal, the stomach muscles first relax, halting any further movement of its contents. The next stage is what is properly called retching, which is several sharp, jerky spasms of the muscles in the chest and of the diaphragm, the powerful muscle sheet that spans the floor of the chest and separates the heart and lungs from the stomach, intestines, and other organs in the abdomen. Part of the retching reflex is to close the vocal cords tightly together. Then comes the actual vomiting. The abdominal muscles squeeze the stomach, the esophagus opens, and whatever is in the stomach comes back out. The vocal cords stay shut, preventing any of the vomited material from getting into the lungs. This is an important protective reflex; when it does not function, stomach contents with all their acid can cause serious injury to the lungs.

We know a lot about what things trigger the vomiting center and how they do it. The particular molecular signals themselves are even known. This information has allowed researchers to fashion drugs that block these signals. These drugs are most effective for the vomiting caused by extremely powerful signals to the vomiting center, such as those that come from cancer treatment drugs. A drug called ondansetron (brand-named Zofran) is an example.

Most parents deal with vomiting children in the context of the stomach flu. For these children, whose vomiting is less severe, doctors generally do not recommend using any of the drugs that suppress the vomiting center. There are several good reasons for this recommendation. The anti-vomiting drugs work on the brain by blocking the action of several molecules that brain cells use to talk to one another, called neurotransmitters. The drugs target neurotransmitters that are particularly abundant in the vomiting center. But these neurotransmitters work elsewhere in the brain, too, and blocking them can cause unwanted side effects, especially in children. There are exceptions to everything in medicine, but since the vomiting from stomach flu is not severe and passes in a day or so, the risk of side effects from these medications generally outweighs the potential benefit of using them.

Is vomiting of any use, and does it help healing when your child is sick? Certainly it is helpful for the body to have a way to get unwanted and toxic material quickly out of the digestive system, and vomiting accomplishes that. Nausea seems a useful thing to have, too, as a way of notifying us to get ready because vomiting is likely to follow.

Until recently doctors deliberately provoked vomiting in children who had eaten something potentially dangerous, and we advised parents to keep ipecac, a drug that does this, handy for such an occasion. We no longer recommend this because the risk of all the retching and throwing up outweighs any benefit of bringing it on. For parents, it is logical to regard vomiting as a natural reflex that may be doing some good in spite of the brief misery it can cause a child. Because the drugs that either block or provoke vomiting can have significant side effects, in nearly all situations it is best to let nature decide when she is going to make use of the reflex.

What causes fever?

June 11, 2010  |  General  |  No Comments

Here is another excerpt from my upcoming book, How Your Child Heals. It’s about fever, from the chapter about symptoms and signs.

Fever means an abnormal elevation of body temperature. But what is abnormal? Most of us have heard or read that “normal” is 98.6 degrees Fahrenheit, which is 37 degrees centigrade. In fact, normal temperature varies throughout the day. It is as much as one degree lower in the morning than in the afternoon, and exertion of any kind raises it. Where you measure it also matters. Internal temperature, such as taken on a child with a rectal thermometer, is usually a degree or so higher than a simultaneous measurement taken in the mouth or under the arm pit.

There is also a range of what is normal for each individual — not all people are the same. So what is a fever in me may not be a fever in you. As a practical matter, most doctors stay clear of this controversy by choosing a number to label as fever that is high enough so this individual variability does not matter. Most choose a value of 100.4 degrees Fahrenheit, or 38 degrees centigrade, as the definition of fever. It is not a perfect answer, but it is a number that has stood the test of time in practice.

We maintain our normal body temperature in several ways. Chief among them is our blood circulation. Heat radiates from our body surface, so by directing blood toward or away from our skin we can unload or conserve heat. We can also control body temperature by sweating — evaporation of sweat cools us down. We know how important a mechanism this is because the rare person who cannot sweat, or who is taking a medicine that interferes with sweating, has trouble keeping his body temperature regulated when he gets sick. If a swing in blood flow inwards to raise temperature happens very fast, we respond by shivering. This is also why we shiver if we go outside without a coat in the winter; our bodies are redirecting blood flow from our skin to our core in order to maintain temperature.

All parents know that a common cause of fever in children is infection. A more precise way to think about it is that a common cause of fever is actually inflammation. Since in children infection is the most common cause of inflammation, we generally assume a child with a fever has an infection somewhere in her body unless we can prove otherwise.

Our brains have a kind of thermostat built into them. Like the thermostat in a house, it senses the temperature of the blood passing by it and uses a series of controlling valves in the blood circulation to fine-tune the temperature. Also like your house thermostat, it continues to sense the temperature, and adjust it as necessary, until it has reached the value for which the thermostat is set. Fever happens when the thermostat is reset, just as happens when you twist the dial on the wall for your furnace — the body reacts to bring itself to the new setting. What twists the knob on the brain’s thermostat to cause fever are substances in the blood.

These fever-inducing substances belong to a family of inflammatory molecules that are released from body cells. Mostly they come from a cell called a macrophage, but germs themselves can also release things that have the same effect. The sudden rises and falls a parent often sees in their child’s temperature when they have an infection reflect the usually brief time these substances are in the blood. Sustained fever for many hours can happen if these materials are steadily present.

Opinions vary among doctors about when fever needs treatment. Fever itself virtually never causes harm on its own. The only times it can do harm is when it gets very, very high — 106 degrees or more — for a sustained period. That only happens in highly unusual situations; ordinary childhood infections never get it that high. It is true fever can make a child uncomfortable, although children generally tolerate it much better than adults. For that reason alone many doctors advise treatment.

There is another reason to treat fever. Toddlers may experience brief convulsions – seizures — when their body temperature rises very fast. These so-called febrile seizures cause no harm to the brain itself, and often run in families, but fever treatment makes good sense for a child who has had them in the past.

We have two effective drugs to treat fever — acetaminophen (Tylenol) and ibuprofen (Motrin). Both work the same way: they reset the brain thermostat back down to a lower lever. Both only last a few of hours or so in their effect, which is why you will see your child’s fever go back up again when they wear off if there are still any of those fever-causing substances from the inflamed site still in the circulation.

How can we treat pain?

June 4, 2010  |  General  |  No Comments

In a previous post I wrote about what causes pain. In this one I’ll write a little about how we can treat it.

We have two main approaches for treating pain: we can do things that reduce the pain signals coming from the spot that hurts, or we can use medications that confuse the brain into thinking the pain is either not there or is not so bad.

There are several simple things we can do to reduce the pain signals coming up the nerve fibers. A simple one has been known to parents for eons — simple rubbing of a painful spot. Stimulating one set of nerve fibers, particularly the fast, insulated ones, affects how our brain processes sensations. Every parent knows how to do this, although you probably did not know why it works. When your child comes running to you after falling down and bonking her head, what do you do? Generally you rub it, and it really does feel better. This is not just from parental love. Stimulating the touch fibers in the same place where the pain is coming from causes them to intervene and dampen back the pain signal coming from the other fibers. The same thing happens when we rub any body part after we hit it on something.

Cooling the area with an ice pack is another way to reduce the pain signals coming up the nerve network. Yet another is to put a medicine that interferes with how the nerves work right on the painful spot. Examples of this approach include ear drops that can numb the ear drum for a child with an infection or numbing sprays and ointments for a child with sunburn. A dentist injecting a painkiller around a sore tooth is using a more powerful version of these same methods.

The other way to treat pain is to use medications that act directly on the nervous system to alter how the brain reacts to the signals coming up from the painful place. They convince the brain to downplay or even ignore the information. This is how both acetaminophen (Tylenol and many other brands) and ibuprofen (Motrin and many other brands) work. Ibuprofen also relieves pain in another way that acetaminophen does not; ibuprofen can work directly at the site, such as the inflamed finger or ear, to block the production of some of those substances that cause the inflammation. We also have an injectable medication related to ibuprofen, only more potent, called ketorolac (brand-named Toradol).

More severe pain, such as from a broken arm, calls for medications more powerful than Tylenol or Motrin. Members of the opiate family, also called narcotics, are the standard. There are many members of this family, which vary in how they are given, their appropriate dose, and some of their side-effects, but they all work in the same way: they go to the brain and the spinal cord and alter a person’s perception of the pain. They also can alter mood and a person’s level of awareness to things around them. A common oral narcotic used for children is codeine; a common injectable one is morphine.

Even though we give narcotic medications for severe pain, a fascinating thing about them is that they are not really foreign to the body at all. We have similar substances that occur naturally in our body, and presumably these natural narcotics, called endorphins, are performing some useful function inside us, most likely involving pain control. So when we give a child with more severe pain, such as a broken leg, a medication of this type we are really just reinforcing a normal pathway. The presence of these natural substances could explain why some persons, an Indian Yogi for example, can walk across a bed of hot coals without pain because he has learned how to alter his brain’s perception of what is painful.

Pain, uncomfortable as it is, does serve some useful purpose, and in that sense helps a child heal. Pain alerts us that something is wrong and tells us we should try to do something about it. If we cannot feel the pain, worse injury often results. A good example of this is what happens when a person lacks sensation in an arm or a leg. Because he cannot feel there, painful things, such as an ill-fitting shoe, can go unnoticed and lead to injury.

But pain can also interfere with healing. Mild or moderate pain does not seem to affect healing much, but more severe pain, if it persists, can interfere with it. This stems from the effects of what we call stress hormones, substances like adrenaline, which the body releases at times of stress. They are called “fight or flight” hormones because they probably helped our ancient ancestors deal with things like a wild animal attack. Although they can help in times of acute danger, prolonged high levels of these hormones, such as occurs with continuing severe pain, do inhibit proper healing. Researchers have studied this phenomenon in children who have had major surgery, and it is clear that using pain-killers does not just make the children feel better — it also makes them heal better.

What is pain, anyway?

May 28, 2010  |  General  |  No Comments

My next book, due out in mid-July, is about healing. Important to understanding healing is understanding the symptom of pain. What follows is an excerpt from my book that talks about this universal symptom – what it is and why it is.

Pain, in all its varieties and subtleties, is among the most complex of human symptoms. It has been described in uncounted ways by writers and portrayed by actors, but we read or view these characterizations through the lens of the pains we ourselves have had. Even though we all have felt pain, and in that sense have shared the experience with all other humans, it is also unique to us. Pain is both universal and profoundly personal. It’s a complicated subject.

Pain is not limited to humans, of course. All mammals certainly feel pain. Some aspects of the pain response reach far down below mammals in the animal kingdom to quite primitive creatures. How these creatures perceive it, if that is even the right word, is mysterious, but this observation tells us pain has been with us for many eons. That fact alone should tell us it must serve some important purpose.

All of us know that pain comes in many forms. There is the sharp pain from stepping on a tack. There is the vague, dull aching of a twisted knee, the cramping pain in the lower abdomen that comes with the flu, the pounding inside the skull of a migraine headache, the gnawing pain of a toothache. There is the restless pain that persists in spite of what positions you take, as well as the pain that only relents when you lie completely still. All of us could think of many more examples.

Pain is reported to the brain via a dense network of nerve fibers. Think of this network as an intricate grid of electrical wires, because that is what nerve signals are made of — electricity. These wires are of several kinds, but there are two principal ones. They differ in how well insulated they are. Instead of the plastic insulation that protects electrical wires, the body uses a substance called myelin to insulate the neural wiring. Some wires are more tightly wrapped with myelin than are others. Some nerve fibers have no myelin at all. The more wrapping, the faster the electrical signal travels, so myelinated fibers transmit signals faster than those without myelin.

The nervous system uses a series of switching stations to pass a signal from, for example, the end of your finger to your brain. The first of these are in the spinal cord. When you prick your finger, an electrical signal goes from a nerve fiber there, up your arm, and on to a relay station in the spinal cord in your neck. From there, it continues on up your spinal cord to your brain. What happens to it when it reaches your there is fascinating — and complicated.

Pain is a subjective feeling, meaning no one besides yourself can know precisely how you are feeling it. This means no two people will experience pain in the same way; the exact same finger prick may be perceived quite differently by two different people. An injured person can even be initially unaware of his injury because he does not feel it at first. Probably you have experienced the situation in which, distracted by something else, you did not feel a stubbed toe or a bug bite to the same extent you would have if your mind were not focused on something else.

This variability in how pain is perceived, of the discomfort it causes us, is because the simple electrical signal running up your finger from that needle prick gets modulated by a maze of other nerve cells in the spinal cord and in the brain. Some of these influences dampen down the signal, others ramp it up. The result is when it finally gets to your upper brain, where your consciousness lies, all sorts of things have affected the signal, things that are unique to you and your brain.

You have several kinds of nerve fibers in your finger. The ones that transmit the fastest signals, the heavily myelinated ones, mostly are concerned with light touch and position sense, which is knowing where your finger is in space. This makes sense, because these bits of information are things the brain needs to learn as rapidly as possible. If you want to demonstrate this for yourself, close your eyes, open your mouth, and rapidly stick your finger in your mouth. You can do this without poking yourself in the eye because your brain knows, every millisecond, just where your finger is in space in relation to your mouth. These nerves are also involved in the pain response, particularly in blocking some of its input in the spinal cord. When they do not work, the perceived pain from a pricked finger is worse.

The nerve fibers in your finger that transmit pain signals, the ones with less or no myelin insulation, can sense three kinds of things: mechanical forces like hard pressure, hot and cold, and chemical substances. If you pay attention when you whack your finger with a hammer, hard as that may be to do, you can distinguish between them in action. You first feel a very sharp, very localized pain. This is a signal from the insulated fibers, which gets to your brain first. An instant later you begin to feel a more diffuse, deeper pain that is less well localized to the precise spot. This is input from the slower fibers with no myelin.

Another way we experience the difference between fast and slow fibers is when we bark our shins on a piece of furniture when walking in the dark. We first feel our leg hit the furniture — those are the insulated touch and position sense fibers at work. After a perceptible lag, we feel like yowling in pain — those are the uninsulated pain fibers catching up with their messages.

I’ll put up another post about what things we can use to treat pain and how they work.

Nitrous oxide (laughing gas) for children during procedures

May 22, 2010  |  General  |  No Comments

I’ve written before about how the current standard of care is to provide some sort of sedation drugs — by mouth or by injection — to relieve pain and anxiety when we have to do things to children that make them uncomfortable, such as sewing up lacerations or doing x-ray studies that require them to lay still for a prolonged period. Pediatric intensivists in particular have become very involved in providing this service for children. There’s even a new professional organization, the Society for Pediatric Sedation, that gathers together doctors and nurses involved in this practice. (I’m a member.)

We have a menu of medications to choose from, but finding the perfect sedative for children is sometimes difficult. All of them have potential issues, although we are used to dealing with these things. Recently there’s been a new agent on the sedation scene, although it’s been around for many years for other uses — nitrous oxide, aka “laughing gas.” It’s been used in the operating room for many decades as a supplement to more potent anesthetics, and outside the operating room in dental offices for well over a century. It has an outstanding safety profile. One of the pioneers in using nitrous oxide for sedating children for medical procedures is Dr. Judy Zier, of Minneapolis Children’s Hospital. Her program is so successful that, in one hospital where I often work, we plan to add it to our toolkit of sedation. I think it represents a real advance in what we can offer children.

What is wheezing, anyway?

May 14, 2010  |  General  |  2 Comments

The traffic analysis of this blog tells me that wheezing — what causes it and what we do about it — is one of the most common search terms that bring people here. It’s a common problem, and I’ve written some about it before. The fact that so many people are searching for information about it tells me that doctors may not be doing a great job in explaining what it is. This post will tell you what a doctor means by the word.

“Wheezing” is one of those words which, when commonly used by non-physicians means one thing (noisy breathing), but which means something else when doctors use it. So, when a doctor tells you your child is wheezing, what is she telling you? To understand that you need to know a little about the anatomy of the lungs.

The lungs are made up of two main components: tiny air sacs (called aveoli), where the business of getting oxygen into the blood stream happens, and the pipes that conduct the air down to the air sacs. This system of pipes begins with the largest of them – the windpipe (called the trachea) – in the throat. It ends with the tiniest of them – called the bronchioles – which are just before the air sacs. Think of the system as an immense tree: the trunk, branches, and twigs are the pipes, and the leaves are the air sacs. Here is a picture.

Wheezing is the noise that happens when the small airways have something blocking them. The blockage most commonly comes from constriction of the airways, but sometimes it may be from debris, such as mucus, obstructing the passage. The sound of air flowing past these choke points in the small airways makes a whistling sound – that is a wheeze. Most of the time it is a sound heard when a child breathes out, not in, because it’s more difficult to get air out than in so that’s when the problem is obvious.

We can hear wheezes with a stethoscope, but sometimes they are so obvious we don’t need one. A more subtle sign of wheezing is when a child takes more time to get air out with each breath than he does to breathe air in.

How do we treat wheezing? Since the most common cause is constriction of the small airways, we typically give inhaled medications to reverse the constriction.

Bottom line: when a doctor uses the word wheeze, we aren’t just describing noisy breathing. We mean a specific thing that has a specific treatment.

What’s your favorite example of the weird way doctors speak?

May 7, 2010  |  General  |  No Comments

Every profession has it’s own jargon. This is often helpful because it lets members of the profession (or trade) communicate with each other efficiently and accurately. Medicine is no different in that regard from a host of other professions. But more than a few doctors get into communication troubles when they use their jargon with patients and families. I can think of many examples of that.

But just as weird are the speech constructions doctors often use, both to patients and to each other. Chief among these is the constant use of passive, rather than active sentence constructions. The passive leaves out who is actually doing stuff, suggesting sometimes that things just happened on their own. For example, instead of saying, “Dr. X did an operation on Mr. Jones,” you often hear “an operation was performed on Mr. Jones.” Or, instead of saying “we decided to do this,” you’ll hear “it was decided to do this.” The actor(s) get left out.

Another very odd construction one often hears, when a particular patient might be helped by treatment X, is that “the patient is a candidate for treatment X.” It sounds vaguely as if the patient were running for office or something.

Most of us have heard odd things like this. I’d be interested in reading yours.

Children and toxic plant poisoning

April 30, 2010  |  General  |  No Comments

As I’ve written about before, we commonly see children in the PICU as a result of some toxic ingestion or other. Toddlers take medicines they shouldn’t, but don’t know any better; teenagers also take medicines they shouldn’t, but usually should know better.

Toddlers also put anything in their mouths, including plants, and some of these are potentially toxic. In fact, between 5 and 10% of calls to poison control centers involve a plant ingestion. Yet hospitalizations of children for plant poisoning or toxicity are extremely rare. Thus, although such exposures are common, serious consequences are rare. Still, it is good for parents to be aware of some of the common plants around the house and garden than can cause problems.

Philodendron leaves, for example, can be quite irritating to the mouth and tongue but don’t cause any systemic effects. At holiday time, the berries of both holly and mistletoe, particularly the latter, can be quite toxic, so it’s important to keep them out of reach of toddlers. Here and here are lists of common indoor and outdoor plants that can cause problems.

What should you do if your child has eaten some plant material that worries you? The answer is to call your local Poison Control Center, the number for which is in the front of most telephone books.

Whooping cough: it’s still very much with us

April 23, 2010  |  General  |  No Comments

Whooping cough, or pertussis, its official medical name, is one of those things we hear our grandparents talk about. It once made many, many infants extremely sick with severe coughing and excessive mucous, and some died from it. The so-called paroxysms of coughing can end with the infant sputtering and blue at the end of the spell, after which he takes a huge gulp of air — the characteristic “whoop.” They tire themselves out so much from coughing that they have little energy left to do anything else, including eating.

We have a vaccine that does a fairly good job of preventing whooping cough, which is why we don’t see much of it these days. But the illness has not gone away. In fact, I just saw a case, one of the many I’ve seen over the years. The protection the vaccine gives tends to fade with age, and studies have shown that a fair number of adults with a persistent, chronic cough actually have infection with the pertussis bacteria that causes whooping cough. If such people come in contact with young infants, typically before those infants have completed (or even received) their vaccinations, the babies can get the infection.

I’ve seen some very severe examples of what can happen then. I described one of these in my first book.

The infection affects children in several ways. Our respiratory tract normally produces mucous every day. This is one of the key ways we protect our lungs from all of the particles in the air, such as dirt, pollen, and dust. When we breathe these particles in, they are trapped by the mucous in our airways, and we then cough the material out, which is why our phlegm looks dark after we have been in a dusty environment. The whooping cough bacteria increase the amount of mucous in the infected child’s airway. In addition to that, the bacteria interfere with how the lungs normally get mucous up from the small airways to cough it out. The result is that a child with whooping couch is nearly drowning and gasping for air between coughs; this gasp at the end of a coughing spell is the “whoop” of whooping cough.

If you are interested in finding out more about this infection, you can find it here and here.