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Saturday, February 16, 2013

Post #37 Asthma: A Pedi Perspective - Part 5 of 5

Frequently Asked Questions:

 I have asthma. Does this mean my child will have it too?

There is definitely a genetic component to asthma, but how big a role genes play is unclear. While there isn't a specific asthma gene, it is more likely that your child will inherit the tendency to develop asthma.

Why does asthma seem to come and go?
Asthma is inflammatory in nature, and there are certain things (triggers) that can cause a flare up.

I don't like the thought of my child being on daily medication. I also worry about the medication losing its effectiveness, and then not working when we really need it to.  Can't he just have meds when he's having symptoms?
Regular use of preventative medications is the best way to calm and prevent flare-ups. If everybody with asthma used the proper medications, the number of hospitalizations and deaths would decrease. Remember, preventative asthma medications are only helpful when used before symptoms begin.  Remember, sunblock only works if you put it on before the sunburn actually occurs.

Will my child outgrow asthma?
Many children will eventually outgrow the propensity to have asthma flare-ups as their lungs mature and their bodies get bigger.  Even then, children who get better with age have a recurrence in adulthood. There is no cure for asthma, although it can be managed and controlled with medication.  The bottom line is that the factors which make a lung asthma-prone can still be present as an adult but the likelihood of flare-ups go down as the lung matures and grows physically larger.

Can food allergies cause asthma?
While asthma is more common in children with food allergies, the presence of food allergies do not guarantee a child will have asthma.

Can the use of asthma medications prevent remodeling changes in the lungs?
Unfortunately the answer is probably not.  More research is needed, but it appears that remodeling changes in the lungs cannot be stopped by diligent use of preventative medications such as corticosteroids - much of this is genetically predetermined.  However, responsible use of asthma medications can decrease the number of bad wheezing episodes and significantly improve the overall quality of life.  How much remodeling matters to overall asthma issues is unclear but we do know that in most children symptoms will improve as they get older.

What is the difference between Albuterol and Xopenex?
Scientifically speaking, Xopenex is just the R-enantiomer of Albuterol, while Albuterol is both a R-enantiomer and S-enantiomer 50:50 mixture.  Practically speaking either medication works as a rescue medication and both are very safe.  Xopenex produces less tachycardia (fast heart rate), however the difference is likely modest.  In children with severe heart conditions it may be necessary to use Xopenex, but for most children either is fine and cost-effectiveness should guide which version of the medication to use.

Post #36 Asthma: A Pedi Perspective - Part 4 of 5

Conundrum of cause

According to a 2010 National Health Interview Survey by the Centers for Disease Control, more than 10 million U.S. children aged 17 years and under have ever been diagnosed with asthma, and 7 million still have it.

The study shows that boys were more likely than girls to become diagnosed with asthma.

Furthermore, asthma cases in children under 4-years-old increased by 160 percent between 1980 and 1994. And there's been a steady increase in the nearly two decades since then.

An analysis by the U.S. Agency for Healthcare Research and Quality states that the percentage of children who use prescription medications for asthma has nearly doubled from 29 percent in 1997 to 58 percent in 2007.

While that could simply mean we're better at diagnosing asthma and have access to better medications, it's still easy to see why asthma is considered the leading chronic illness in kids.

But we don't really know why.

There is definitely a genetic component to asthma.  How big a role genes play isn't clear, nor is it obvious whether or not the environment is a factor – and if so, to what extent.

The "hygiene hypothesis," says that early exposure to the dirtiness of life helps prevent asthma.  If your child isn't exposed to dirt, other kids, and cold viruses early on, it leads to an imbalance in the immune system that in turn increases the risk of developing asthma. 

One real-life example of this is the fact that country boys have less asthma and allergy issues than city boys.  They grow up around animals and are exposed early on to lots of thing, thus the immune system is more balanced and less prone to asthma and allergies later on.  However, keep in mind that even country boys get asthma, just less so than city boys.  It seems that early exposure to “life” reduces the risk of asthma - but doesn't entirely prevent it. 

That's because the overall likelihood of developing asthma is multi-variable:  Environment, genetics, number of early colds, allergies, and other factors all play a part.  Sometimes the genetics are too strong to overcome.  But just because asthma runs in the family does not guarantee your child will develop it, although they do have a higher risk. 

Should asthma actually manifest itself, it's important to avoid the triggers that exacerbate it. Therein is the "Catch 22."  Early on, when there is no asthma, let your kids be exposed to stuff and hopefully they will never develop asthma.  Yet should your child eventually get diagnosed with asthma, from that point on you may need to avoid the things that trigger it. 

Triggers are things that make asthma worse or can cause an asthma attack – defined as any acute change in symptoms that interrupts your child's normal routine or requires medical intervention.

  • Exercise:  The majority of children with asthma will present symptoms when they exercise such as coughing and wheezing.
  • Pollen:  This is a common allergen.  Most children with asthma have allergies, and allergies are a major trigger of asthma symptoms.
  • Animals with fur or hair:  Keep pets out of your child's bedroom, remove carpeting, and install a HEPA filter.
  • Mold:  Control indoor humidity.  Repair water leaks no matter how small.
  • Dust mites:  These critters live in mattresses, pillows, upholstered furniture, and carpets.  Get allergy-proof bedding and pillowcases.  Frequently wash bedding in hot water.  Avoid stuffed toys.  Vacuum and dust often.
  • Weather changes:  When air quality is poor, keep your children indoors and make sure they are compliant with asthma medications.
  • Airborne chemicals or dusts:  Try to avoid things like scented candles and air fresheners.
  • Menstrual cycles:  Monthly hormone fluctuations can trigger symptoms.  Make sure your daughter is compliant with asthma medications.
  • Viral infection:  Symptoms may flare with a cold.
  • Smoke:  Avoid tobacco and wood burning.

While parents do their best to make sure the home environment is asthma friendly, don't forget to check daycares, school and relatives' homes. Some triggers can't be avoided, which is why it's important to make sure your child is compliant with his or her medication regime.

That being said, there is no guarantee that an asthma outbreak or attack can be foiled by regular preventative medicine.

There are many different strengths of preventative medicine, and these are tailored-based on the severity of the asthma.  The hope is that as kids get older, they outgrow their propensity to have asthma flare-ups and can eventually be weaned off medications.

Nearly half of children will have a decrease in asthma symptoms by the time they hit adolescence, but about half of those will develop symptoms again when they're adults.

So even though asthma cannot be cured, both you and your child can breathe easier knowing that it can be controlled – and that even after a diagnosis of asthma, he can get back to the business of being a kid.

Post #35 Asthma: A Pedi Perspective - Part 3 of 5

Tenets of treatment

Inhaled medications are the mainstay of therapy, and are delivered two different ways. The first is a nebulizer, which is a machine that emits humidified air combined with medication. The child inhales the air through a mask.

The other way to receive inhaled medication is through "Metered Dose Inhalers." MDIs are the puffers that most people are familiar with. Medication is sprayed directly into the mouth, but a contraption called a "spacer" helps make sure the medication goes directly into the lungs. Using an MDI without a spacer leads to half of the medication missing its mark – a waste of money that also comes with the risk of under medicating.  In general, MDIs (as opposed to nebulizers) are cheaper, more portable, and quicker and are therefore becoming the modality of choice in pediatrics.

So what's in the medication? The two most common groups of meds are preventative medications of which corticosteroids are the mainstay and rescue medications of which albuterol is the mainstay.

Inhaled corticosteroids are used on a daily basis, whether the child has symptoms or not, to prevent future episodes of wheezing. Think of it as sunblock for the lungs. The child puts it on every day to prevent future troubles.

Beta-agonists are the Aloe vera that soothes the sunburn once it happens. Albuterol is the most commonly used beta-agonist. It works by relaxing the muscles of the airways in the lungs, helping them open to let more air through. The effects of Albuterol are short lived. It needs to be given again and again, usually every four hours, until symptoms subside. The Albuterol, or aloe Vera, makes one feel better after the burn, but does not prevent future episodes. Only sunblock, or inhaled corticosteroids, can do that.

Some parents get freaked out by the word "steroids," picturing pumped-up athletes risking illegal consumption just to make their muscles bigger. Rest assured that corticosteroids are not the same thing. Corticosteroids are similar to steroids that already occur naturally in the body.

That being said, corticosteroids can affect your child's height by causing temporary growth delay. But if that’s the case, it's very minimal, and should resolve through catch-up growth once the medication is stopped. It will not prevent your child from reaching his or her genetic potential in height. And, keep in mind that the side effects of corticosteroids are considerably less serious than the side effects of poorly-controlled asthma – which includes stunted growth overall, even death.

Post #34 Asthma: A Pedi Perspective - Part 2 of 5

Diagnosis is in the details

Asthma is a disease that is diagnosed by history.  In other words, one cannot make a diagnosis of asthma the very first time a child wheezes.  It's like your friend who show up late to your home for dinner; it would be premature to label them "tardy" after one episode, but if they come late multiple dinners in a row, they are likely "tardy" friends.  With every subsequent wheezing episode, the more likely these are not one time events but a sign that there is underlying asthma.

If asthma is suspected, your child may be referred to a lung specialist for a series of pulmonary function tests - this is typically needed in the more severe cases while the milder cases can be handled by an experienced pediatrician.   Not only will this confirm the diagnosis, it will help define the severity of the disease.

These tests are designed to measure lung volume and respiratory muscle function, but must be performed correctly in order to be accurate. It's not very easy to measure lung function in small children, which is why pediatricians rely heavily on history. The more episodes of wheezing and shortness of breath a child experiences, the more likely the child is asthmatic.

Another way to diagnose asthma is to start children on asthma medications and see if they respond. If they respond positively, meaning they experience an easing of symptoms, they probably have asthma. If the medication does not help, the wheezing and coughing is probably secondary to a cold virus.

The diagnosis of asthma can be tricky, and while there are tools to help, it requires the combination of history, tests, and serial exams to be as precise as possible.

Post #33 Asthma: A Pedi Perspective - Part 1 of 5

It's difficult to diagnose, can attack without warning, and unfortunately we don't know exactly what causes it.

It's said to be the most common chronic medical problem in children, fortunately it's manageable with medication.

Asthma is a lung disease that causes inflammation and narrowing of the airways, making it hard to breathe.

While it affects people of all ages, it most often starts in childhood. According to the American Academy of Pediatrics, between 80 to 90 percent of people with asthma develop symptoms by the age of 4 or 5.

Parents tend to worry at the first sign of a cough or wheeze, but in reality, a one-time episode is not indicative of asthma. That would be like labeling a friend of yours "tardy" just because she showed up late one time.

Further coloring the diagnosis of asthma in shades of grey is that children with asthma can present with different symptoms at different times.

When to wonder

The most common symptoms of asthma are coughing, wheezing, chest tightness, shortness of breath and difficulty breathing.

Coughing is a protective mechanism designed to move mucus through the respiratory track. In a child with or without asthma, coughing can be worse at night because during the day gravity and activity helps mucus drain and clear from the airways; however at night, laying horizontal and the lack of movement allows mucus to pool in the airways thus increasing the coughing bouts.

Coughs caused by a virus can last anywhere from two to six weeks or sometimes even longer, but chronic coughing - coughing for more than eight weeks - should be brought to the attention of a doctor.  Although asthma can present with just coughing, an experienced doctor can help distinguish between a cough caused by a cold virus (or other germs) versus a cough secondary to asthma.  It should be noted however that in a child with asthma, cough is often initiated by a cold virus and exacerbated by the underlying asthma producing a mixed picture, hence it may take a few visits to delineate whether asthma is a true player or not.

Often the easiest way to differentiate the two is a trial run of asthma medications to see if there is a response to the medications or not. If there is a response, the good news is there is something you can do for the cough. The bad news is your child may have asthma. If there is no response to the medicine, the good news is your child is unlikely to have asthma. The bad news is there's not much you can do about the cough.  Keep in mind that in children with asthma, there is usually a mixed picture of a cold virus triggering asthma symptoms; in other words the asthma medications will help control the asthma but not the symptoms brought on by the cold virus itself, so a positive response may not be a complete response.

Although asthma can present with just coughing, a child with true asthma will typically have a chronic cough combined with wheezing.  However, note that what most moms call wheezing and what most doctors call wheezing often differ.  There are many sound-a-likes to wheezing that can be best distinguished by an experienced clinician.

Wheezing occurs when the muscles in the airway tense up or clamp down due to inflammation. The result is decreased diameter in the airways, making it more difficult to move air. Just like you make a whistling sound when you purse your lips and breathe, the airways also make a wheezing sound when the diameter is narrowed.

Just as a chronic cough on its own does not mean your child has asthma, a wheezing episode alone is not necessarily indicative of it either, since both of these things can happen in response to a bad cold. A cold virus may cause just enough inflammation in the lungs to cause a one-time wheezing episode.

That being said, kids with asthma will not only wheeze chronically but their lungs will actually show changes that can be seen under a microscope. This is called "remodeling."

Airway remodeling is a response to long-term airway inflammation that can lead to permanent structural changes.

Asthma is more likely to manifest itself in long-term changes if it shows up before age 3, with the child displaying obvious symptoms of these changes by age 6.  Asthma that starts after age 6 is less likely to become a long-term problem.