Indoor Mold Exposure and Childhood Wheezing

I’ve written before on the topic of indoor mold and while the issue has received lots of attention in the press, there hasn’t been much good science published on it.  There still isn’t a ton of great data out there, but this month’s Annals of Allergy, Asthma, and Immunology does have an interesting article looking at early childhood mold exposure and risk of developing asthma.

As with most published studies, the devil is in the details.  Whenever I read an asthma study, one of the most important questions I ask myself is how did the authors define asthma.  In many studies, patients are defined as asthmatic based on parental report or prior physician diagnosis.  I consider these to be weak definitions because they are so subjective.  The recent Annals study, however, used what I consider to be the best criteria: bronchodilator reversibility or methacholine challenge, which are the gold standard in asthma diagnosis.

Next, I wanted to know how the authors assessed for the presence of mold in homes.  For the uninitiated, such details are always contained in a section of an article called “Methods”.  Digression- If you’re in a hurry and you just want the quick and dirty info, many docs, including yours truly, will often read the abstract then skim the results and discussion.  But to truly understand an article you have to read the methods section.  It often contains phrases like this one from our aforementioned Annals study, “A Bayesian change-point analysis was applied to the logit of predicted values from a nonlinear regression of asthma on the ERMI.” I have no earthly idea what that means and I’d venture that most of the authors don’t either.  That’s why we hire statisticians to help us use the proper statistical techniques.

The methods section of this article contained a couple of interesting, and perhaps mildly humorous, points.  First, “an indoor visual and olfactory observation of the house conditions was conducted for the presence of carpets and evidence of mold.”  That’s a very sciency sounding way of saying they went looking and smelling for mold.  They did, however, perform a quantitative analysis by sampling house dust and performing an ERMI.  What’s an ERMI, you ask?  That stands for Environmental Relative Moldiness Index.  I think using the words “relative moldiness” in a scientific measure is hilarious.  They should try to make it more formal sounding.  Anyway, I was unfamiliar with the ERMI so I looked it up and it does seem to have some validity- it basically uses PCR to quantify mold spores levels in a sample of house dust.

So what did the study find?  Well the blurb you’ll see is that kids from a high ERMI home at 1 year of age were 2.6 times as likely to have asthma at age 7.  Interestingly, there was no correlation to allergic sensitization to mold, however.  So, either molds increase the development of asthma via a non-allergic mechanism, they needed to test for more kinds of mold, or there is some other confounding factor that goes along with a high ERMI level, like dust mites, for instance.  Cigarette smoking in the home also raised the risk of asthma at age 7.  The use of home dehumidifiers, presence of carpeting, age of home, and the categorization of home moldiness based on visual inspection did not correlate with asthma at age 7.

Overall, this is a well done study that raises good questions and sets the stage for further research into this area

OTC allergy eye drops

Now’s the time of year for allergy eyes.  If you’re looking for some OTC relief, you’re in luck.  There are good OTC allergy eye drops, though it seems that many people aren’t familiar with them.  Look for drops containing the active ingredient ketotifen.  It’s found in Alaway and Zyrtec eye drops.  I recommend avoiding drops with tetrahydrozoline or naphthazoline. These are “get the red out” medications and can cause some rebound problems if used too much.  Sort of like Afrin for the eyes.

Hope this helps.

Dr. O

“Fake Doctor” providing allergy care in Nashville

The FBI has indicted Matthew Paul Brown for health care fraud for a scheme carried out in the Nashville and Atlanta areas.  Mr. Brown allegedly convinced primary care physicians to allow him to perform allergy diagnostic testing and treatment which the physicians would then bill under their names.  The indictment states that, in return, Mr. Brown would receive 50-85% of the revenue which totaled $1.2 million.

This is distressing for a number of reasons.  I find it particularly disturbing that any physician would allow someone with questionable medical credentials to provide care, much less specialist level care, for their patients.  This is a clear case of greed outweighing the best interest of the patients.  Any physician who knowingly fraudulently bills insurance companies is a crook and  any physician who knowingly fraudulently bills government insurance is a foolish crook.  It is disheartening to know that there are physicians who do this.

It is also concerning that there have been what would appear to be a great number of patients who have been receiving substandard allergy care.  Here at AAAMT, both Dr. Norvell and I are board certified in allergy and immunology, a process which took years of extra study, and we devote all of our clinical time to the care of allergy patients.  Our mid-level providers have years of subspecialty allergy experience under the guidance of board-certified allergists and our nursing staff is focused full time on allergy care.  We take great care to provide up to date diagnosis and management  and to adhere to the guidelines set forth by our specialty societies.  We feel that all this provides patients with the highest level of allergy care, a level which cannot be achieved in other medical settings.

So I’ll end this rant with the message I’ve said before: If you’re having allergy issues that aren’t controlled by simple medications, seek out a board-certified allergist to get the best possible care.

New Food Allergy Guidelines

The AAAAI just published new guidelines regarding food allergy.  The text is 60-odd pages of dense reading, but it does contain some new stances and one, in particular, that I’ve been harping on for some time.  I’ll quote the text:

“[Skin prick tests] and measurements of sIgE antibodies to detect
sensitization to foods provide very sensitive means of identifying
foods that may be responsible for IgE-mediated
food-induced allergic reactions. However, these tests have
poor specificity and show relatively poor overall correlation
with clinical reactivity. Consequently, if used alone, they
lead to a gross over-diagnosis of clinical allergic reactivity.“

Much of our current food allergy “epidemic” is really an epidemic of bad food allergy testing.

The expert panel also recommends against utilizing standard panels containing large numbers of food allergens for the same reasons outlined in the above quote.  Foods selected for testing should be based on an individual’s medical history and carried out by someone knowledgeable in the selection and interpretation of such tests.  In other words, leave food testing to the allergists and stop routinely ordering food tests.

Here Comes the Sun: Vitamin D, Allergies, and Asthma

Every few years there’s a hot new allergy topic that’s going to explain and/or cure the growing problem of allergies.  Several years ago it was the so-called Hygiene Hypothesis which basically said that fewer childhood infections meant more allergies.  It made some sense immunologically, too, but results of studies looking at it have been mixed.  The new hot topic is Vitamin D deficiency.  Let’s take a look, shall we?

Back in the day, I did my internal medicine training at the University of Virginia.  UVa is known for several things: mostly for being Mr. Jefferson’s university, but also for being Ralph Samson’s alma mater and for being the home of the finest bagel shop on the planet, Bodo’s Bagels.  In the allergy world, it is known as the home of Dr. Thomas A.E. Platts-Mills, a leader in our field, and the father of dust mite allergy.  I had the opportunity to spend some time in residency working with Dr. Platts-Mills and he is a brilliant man.  Like all truly brilliant people, however, he’s thinking on a different plane from the rest of us and some of his ideas seemed a bit out there.  That, coupled with his inscrutable British demeanor often left me wondering whether I was being mocked or instructed, laughed at or laughed with.  In any event, one of Dr. Platts-Mills pet peeves was television.  The man could not stand TV and one of the first tings he would tell parents of allergic children was to throw away their TV and get their kids outside.  If the growing body of literature on Vitamin D is correct, he was probably right.

Humans get Vitamin D from 2 sources: sunlight and diet.  Historically, over 90% of our Vitamin D has come from exposure to sunlight which, in simplest terms, kick starts the reaction that leads to Vitamin D production.  Vitamin D is relatively scarce in our natural diet, but is added many common foods like milk and sugary breakfast cereals, so we now obtain a higher percentage through diet.  Even with supplementation, however, as we spend more time indoors watching Spongebob, playing on the Wii or blogging, our natural source for Vitamin D is waning.  Recent research suggests that around 1 in 10 kids is Vitamin D deficient and that an additional 60% of kids may have Vitamin D insufficiency!

So how does this relate to allergies and asthma?  Most studies looking at this are merely observational  and therefore show correlation, but not causation.  That is, low Vitamin D might be a marker for allergies and asthma, but not a root cause.  When you look at Vitamin D’s effects on the immune system and on other cells in the body, there is enough there to make a reasonable hypothesis that Vitamin D deficiency may be a contributing factor to allergies and asthma and that Vitamin D supplementation could be a potential treatment for people with deficient or insufficient levels.

Of course, you could always just throw away your TV and get outside……..

Important note on Vitamin D Supplementation: Vitamin D is one of the fat soluble vitamins, along with A, E, and K.  This means that your body stores it up rather than just getting rid of it through the urine, like it does with Vitamins B’s and C.  Thus, over time, if you take too much of a Vitamin D supplement, you can develop Vitamin D toxicity.  If you do use Vitamin D supplements, be sure to follow the recommended doses.

How are Allergies Like My Dog?

I have a freakishly large Golden Retriever named Ozzy.  He performs some important household chores like waking me up at 6am every day, pre-rinsing the dishes in the dishwasher and destroying any rogue tennis balls that might be laying around the house.  He’s two, now, which for a Golden means that he’s still really energetic. If I don’t find time to let him do what he was bred to do, run around like crazy chasing stuff then bringing it back to me, he will start to act out.

The immune system of an allergic person is sort of like Ozzy.  It’s designed to to a specific job and do it well and when it isn’t presented with the chance to do that job, it will find something else to do.  The part of the immune system that is responsible for allergies is really designed to fight off parasites.  We don’t have a big parasite problem is the Western world anymore, but we do have a huge, and growing, allergy problem.  One theory as to why allergies are becoming more common states that since the parasite arm of the immune system is not required to do its job much anymore, it goes looking for something else to do.  What it finds, instead of parasites, is pollens, dust mites, peanuts, and the rest of the common allergens.  It incorrectly senses that these things are potentially harmful and it sets up a reaction to get rid of them.  That reaction causes the symptoms experienced by allergy sufferers.

Some people have taken this theory as far as infecting themselves with hookworms to see if it improves their allergies and there are anecdotal reports of this process working.  Usually these reports come directly from the people selling the worms, however.  There is serious research into this treatment going on at present and the results should interesting.  For now, though, we’ll stick to antihistamines, nasal steroid sprays, and immunotherapy.

Whooping Cough: Don’t Call it a Comeback….

California is in the midst of its worst whooping cough outbreak in 50 years.  Before a vaccine was available, whooping cough killed around 5000 Americans a year, mostly infants.  Add to that the substantial morbidity it caused and whooping cough was a major public health issue.  When the  whooping cough vaccine became available in the 1940’s, the number of cases declined precipitously.  Since the 1980’s, however, the number of whooping cough cases has been on the rise.

Whooping cough is not a trivial disease. It is caused by a bacteria called Bordetella pertussis that infects the lungs.  Apart from the small mortality risk, the two things that make whooping cough so bad are the intensity of the disease and the duration.  The “whoop” in whooping cough refers to the characteristic noise made when its sufferers cough.  It has also been referred to as a bark, honk, or seal-like noise.  The cough is so severe that it is not uncommon for sufferers to cough until they vomit or crack ribs.  Whooping cough is also known as the “100-day cough”.  After the acute illness subsides, the cough can linger for months.

Back to California.  A recent NY Times article illustrates some of the reasons for the return of this old foe.  It highlights Marin County, a wealthy bay area enclave that is home to 0.5% of the states’ population, but 15% of the states’ whooping cough cases.  In Marin county, 13% of infants and children remain unvaccinated, the 7th highest rate in the state.  It is this lack of vaccination that allows diseases like whooping cough to gain a foothold in a community.

I’ve said it before in this blog, but it bears repeating:  vaccines may be the most important public health advance in the history of mankind and that is not hyperbole.  In order for them to be maximally effective, to achieve herd immunity, they need to be used universally.  Some vaccines are better than others, but they are all better than nothing.  The risks of vaccination are negligible, especially when compared with the risk of not vaccinating.

Finally, when considering not vaccinating your child, remember that you  are not only putting your child at risk, but you are also increasing the risk for every other individual in the community.

More news on the diagnosis, or misdiagnosis, of peanut allergy.

Hey! We’re back.

I took a little hiatus from the blog.  We had a really busy tree season, I moved into a new house, and we had a little rain in the Nashville area.  My thoughts have been elsewhere.

For my re-entry post I thought I’d touch on a recent article looking at the mess that is peanut allergy diagnosis.  I’ve written about this before and related the uncertainty inherent in interpreting food allergy tests- particularly food allergy blood tests.  In simplest terms, food allergy testing is very good at ruling OUT allergies, but when the test comes back positive then in doesn’t necessarily indicate a true allergy.  How do we handle this?

It may be helpful at this point to draw a distinction between sensitization and allergy.  When an allergy blood test comes back positive, that shows sensitization: the body’s immune system has come into contact with that substance and has responded to it by making a specific allergy antibody, sIgE in the medical shorthand.  The problem is that sensitization to a substance does not mean a person is allergic to that substance.  An allergic person will have a reaction when exposed to that substance, but many people who are sensitized are not allergic.

Are you more confused?  Lets look at the study to clarify.

Researchers in the U.K. and Sweden tested 933 kids and found that around 12% were sensitized to peanut (had a positive test), but only about 2.5% had true peanut allergy (reacted when they ate peanuts).  That means that 75-80% of kids with a positive peanut test weren’t peanut allergic in this study.  Imagine how many families are needlessly stressing over peanut allergy!

The study used oral peanut challenges-having the kids eat peanuts- as a gold standard for diagnosing peanut allergy.  Most community allergists don’t do this because they lack the resources to properly carry out the test.  Many families are wary of doing this because of the risk of severe reactions.  These researchers used a new test called component resolved diagnostics (CRD)to see if they could better identify who was truly allergic and who was simply sensitized.  CRD works like a usual allergy blood test except that it measures sensitization to very specific parts of the peanut protein.  The researchers found kids who were sensitized to one particular peanut component, called Ara h 2 if you need to know, were much more likely to react to peanuts.

This is only one study and I’m not sure yet how CRD will fit into clinical practice just yet.  However, I think it is very promising and I’m hopeful that it will give us a useful tool to better diagnose and manage peanut allergy.

Dr. O

Update on the FDA and Long-Acting Beta-Agonists

I’ve posted before on the issue of LABAs and safety.  LABAs are medications that help keep the airways open fro 12 or so hours.  Both Advair and Symbicort have a LABA in them.  Concerns have been raised about the safety of LABAs, primarily based on flawed data from poorly done trials.  Nevertheless, the FDA has responded again to this issue, despite the fact that there is no new information on LABAs and safety.  The FDA is simply issuing another proclamation based on the same data that the last proclamation was based on.  Curious.  If the data is the same, I don’t see why the recommendations should be any different.

In fact, most of the recent recommendation from the FDA does not differ substantially from the previous one.  First, they reiterate that LABAs should not be used alone without using an inhaled corticosteroid at the same time.  (Both Advair and Symbicort contain an inhaled steroid in addition to a LABA.)  Second, they reiterate that LABAs should only be used in patients for whom other medications, usually simple inhaled steroids, have been ineffective.  Neither of these points is new or controversial.

They now recommend that children and adolescents using combination inhaled steroid/LABA therapy only be given devices which contain both.  That is they should not have a steroid inhaler and a LABA inhaler, but should use either Advair or Symbicort.  I don’t know for sure, but I’d guess that 99% of children or adolescents using combination therapy are already using a combination inhaler.

The point that is causing some controversy is this, and I’ll quote for accuracy, “ LABAs should be used for the shortest duration of time required to achieve control of asthma symptoms and discontinued, if possible, once asthma control is achieved. Patients should then be maintained on an asthma controller medication.” I think that this is a bad recommendation, and apparently so do some other asthma physicians. After yesterday’s press conference, some members of the American Thoracic Society asked for clarification on this statement.  The FDA’s response was much more tempered, “ The FDA’s intention is to encourage patients and providers to seek to reduce LABA use as much as possible if symptom control can be maintained without it. However, the FDA recognizes in some cases, discontinuation of LABA use, or even reduction of LABA use, may not be possible.”

I agree with the overriding principle of utilizing the minimum amount of medication needed to maintain adequate control, but the FDA’s recommendation does not follow this principle.  Rather it seems to say, “Wait til your patient gets sick, then add on more medication.  When they’re better stop til they get sick again and restart.”  Lather. Rinse. Repeat.  I would suggest that maintaining good control, preventing exacerbations, is a much better idea and if that means keeping the LABAs on board, then so be it.

I’m sure this won’t be the last of this issue.

Dr. O

Does Your Child Really Have Food Allergies?

Here’s a common scenario in my office:  A parent has taken their child to the primary care physician’s office to talk about possible allergies.  The physician sends off a “screening allergy panel” blood test which contains a few common airborne allergens like pollens, dust mites and cat dander.  The panel also contains tests for common foods like peanuts, milk, eggs, and soy.  A few of the food tests come back as positive and the parents are told their child has food allergies and needs to see an allergist.  The parents have heard horror stories about food allergy reactions and are scared stiff that their child may have one, even though he has always tolerated these foods in the past.  What do you do next?

Melinda Beck at the Wall Street Journal recently wrote an excellent article on this conundrum.  You can find it here. I highly recommend it.  It reiterates what allergists have been telling patients all along:  blood tests can be poor predictors of true food allergy.  A test is just a number, a patient is a person.  There’s a big difference.  In some studies, over 50% of kids tolerated foods they had been told to avoid.

These problems could largely be solved with a few simple steps.  First, and this is directed to the primary care physicians, STOP ORDERING FOOD ALLERGY TESTS INDISCRIMINATELY.  Sorry to all-caps and bold that, but I can’t stress this enough.  If the history does not suggest food allergy then there is no indication for ordering food allergy tests.  Simple rhinitis, sinusitis, otitis, and asthma are not food allergy related and foods have no place on a screening panel of allergy tests when evaluating these disorders.  To quote from Ms. Beck’s article, ““Are these blood tests being overused? Possibly. Misinterpreted? Absolutely,” says Robert Wood, director of Pediatric Allergy and Immunology at Johns Hopkins Hospital…”

Second, and this is directed at the labs running the tests: Stop putting foods in your screening allergy panels and stop marketing such panels to primary care docs.  This practice wastes money on needless tests and causes confusion and anxiety for countless families.  In short it is irresponsible.

Third, if you have questions about allergies, see you local board certified allergist.  In most cases a simple history will be enough to tell true food allergy from false positive blood tests.  Allergists have years of specialized training and experience in the proper selection and interpretation of allergy tests and the management and treatment of allergy problems.  They are best suited to help you solve these issues.