News from the TSAAI

The Tennessee Society of Allergy Asthma and Immunology met this weekend and there was a great turnout and some excellent speakers.

For me, some of the clinical highlights were:

• The search is on for histamine-3 receptor blockers, which should be very effective treatments for nasal allergies and itching
• There are numerous reports of severe reactions to SLIT
• Data on SLIT dosing schedule, appropriate dose, time to improvement, and magnitude of benefit is still a huge mess
• American experiences with SLIT have failed to replicated the wildly successful outcomes of the Italians
• Duke University’s Wes Burks has been able to desensitize a number of children with peanut allergy using an oral administration protocol
• The number of obese adults in the southern U.S. has doubled in the last 20 years.
• In India, asthma causes 150,000 deaths per year. In America its around 4000.
• The pediatric dose of levocetirizine, Xyzal, is too low.

Some of this was new to me and some confirmed what I already believed. If our readership has questions, drop us a line and I’ll try to answer.

Dr. O

Can we help prevent food allergies in our kids?

With the incidence of food allergies on the rise, I’m often asked by parents if there is anything that can be done to help prevent the development of food allergies in their kids. The unfortunate answer is, not really. Several recent studies have cast doubt on some conventional recommendations, which were probably made without much data to support them in the first place.

One recent study examined the theory that kids can become sensitized in utero, a theory which has led some to recommend avoidance of allergenic foods during pregnancy. The study found evidence of allergy antibodies in cord blood around the time of birth in a number of children, but at a 6 month follow-up, none of these children had any allergy antibodies in their blood and therefore, none had become sensitized in utero. The authors surmise that antibodies were found in cord blood due to contamination with the mom’s blood. The data from this study and others leads to the conclusion that maternal avoidance of highly allergenic foods during pregnancy and lactation has not proven to reduce allergy in kids, though the data on eczema are less clear.

Several recent studies have examined breast feeding and the development of allergies and asthma. One would think that the natural proteins and antibodies found in breast milk might lead to a decrease in sensitization, but apparently it doesn’t. Exclusive breast feeding will reduce wheezing in very young children, probably through a reduction in respiratory infections, but has been shown to not reduce the incidence of asthma at age 7, 13 and 19. In fact, one large study suggested that there was actually an increased risk of asthma in kids who were exclusively breast fed for the first 4 months. There certainly are numerous benefits to breast feeding, but it looks like preventing allergies is not one of them.

Finally, when should we introduce highly allergenic foods into our kids diet? There is no good evidence to support delaying the introduction of foods such as milk, eggs, nuts, and fish beyond 4 to 6 months. This was confirmed in a recent large trial in Germany, which actually suggested that delayed introduction of solids resulted in an increase in the incidence of allergies at 6 years of age. Now, if I could just get my son to eat something besides chicken fingers that would be a real breakthrough!

A bit about molds

I am commonly confronted with patients who are concerned about mold exposure, both at home and at work. This can be a tricky issue, since molds can cause problems via allergic and non-allergic mechanisms. Molds also been implicated in a wide variety of problems, though there is a paucity of good science to back up many of these accusations.

First, a word about molds in general. Molds are a natural part of the outdoor environment. One of their major functions is degradation of organic material. In English, this means they are nature’s recyclers. They take dead plant and animal matter and turn it into dirt. The life cycle of molds can be very complex, but at some point they produce a spore which can become airborne. It is these spores which can lead to allergy problems. Damp conditions and an abundance of vegetation equals lots of mold spores.

For molds to become an indoor problem, there must be excessive indoor moisture. Often this follows areas of water damage or leaks. If water beads up on the inside of your windows, then there’s too much moisture. The best simple test for molds is still your eyes and nose. If you can smell it or see it, then its a problem. If that’s not satisfactory, then there are good tests for indoor mold levels. Simply placing a petri dish on your dresser is not a good test! Since molds are a normally present in indoor air, this test will always grow some type of mold. A proper test involves volumetric sampling, where a device that looks like a dust-buster takes in a fixed amount of air from several places inside and outside the home. The amount of mold that grows from each sample is the quantified and if there excessive growth from an indoor sample compared to an outdoor sample then there is a mold problem.

Excessive indoor molds cause respiratory problems via both allergic and non-allergic mechanisms. They can cause nasal and chest allergy symptoms in much the same way that other airborne allergens do. These allergies can be tested for and respond to medications and immunotherapy. Molds can also cause problems via non-allergic mechanisms. They release chemicals called volatile organic compounds (VOC’s) which are respiratory irritants. The symptoms they elicit are similar to allergy symptoms, but there is no test for sensitivity to VOC’s and they do not respond to immunotherapy.

The link between mold exposure and respiratory symptoms is reasonably clear. The myriad other complaints that have been blamed on mold have little evidence to support them. The infamous, inflammatory term, “toxic mold” is a term created by litigators and sensationalist news programs, not by physicians. If you have concerns about mold problems, your local allergist can probably help.

Seasonal Allergens

Pollen allergies are largely responsible for the classic hay fever symptoms of sneezing, itchy, watery eyes, and runny nose. Allergists generally divide pollens into three types: tree pollen, grass pollen, and weed pollen. Each type has a discrete season during which it is the primary pollen. The rule of thumb for temperate climates, like we have here in Nashville, is tree pollen in the spring, grass pollen in the summer and weed pollen in the fall. Of course, this may vary based on your local climate. So, if you’re mowing your lawn in April and you have a bad flare, it’s not the grass, but the tree pollen that’s responsible.

So what can you do about pollen allergies? Like most inhalant allergies, the three options are avoidance, medications, and immunotherapy. Avoidance can be tough for outdoor allergies, since it can take very little time to get a massive exposure and no one wants to be locked indoors for months on end. Pollen counts tend to be the highest in the early morning, so avoiding prolonged exposure during those hours may help. Also, rinsing off after being outdoors will help remove pollen grains that may be lingering in the hair or on the skin. If you must mow during your peak pollen season, a mask can be helpful.

Medication-wise, the starting point for most people is a simple antihistamine. Over-the-counter options have improved significantly with the addition of loratadine and cetirizine to the market. Antihistamines work best for symptoms of sneezing, itchy, watery eyes and runny nose. They are not very helpful for nasal congestion or drainage.

If these simple options don’t work, then its probably time to go visit the doctor. A trial of a good nasal steroid spray is usually warranted at this point, and if that doesn’t work well, causes side effects, or you experience complications from allergies like sinus infections, ear problems or asthma, then it’s time to get allergy tested.

Asthma Control

“My asthma is fine as long as I take my albuterol 4 times a day and don’t exert myself”.

Yikes! That’s a fairly common statement, and it illustrates the disconnect that exists between people’s perception of asthma control and the reality of asthma control. Asthma control is important, since poor control is linked to more frequent and severe exacerbations, hospitalizations, emergency room visits and diminished quality of life.

Asthma control is largely defined by the severity and frequency of symptoms and how much they interfere with normal activities. (Asthma severity is a much more complicated classification and involves measurements of lung function.) A simple 5 part questionnaire called the Asthma Control Test, or ACT, has been shown to be an excellent measure of control. A score of twenty or above on the ACT indicates good control. Another simple test is known as the “Rule of Twos”: If you have to use your rescue inhaler more than two times a week or you are waking up at night with asthma symptoms two or more times a month, then you are not as well controlled as you should be.

The goals of asthma therapy are to have minimal symptoms, no exacerbations, and minimal interference with activities of daily living. Achieving this requires proper medications and the identification and control of triggers such as allergies, reflux, and sinusitis. The National Heart, Lung, and Blood Institute’s guidelines for the diagnosis and management of asthma recommend allergy evaluation for all asthmatics who require regular controller medications. Your local allergist is an asthma expert who can help improve your asthma control and quality of life.

Sublingual Immunotherapy

Sublingual immunotherapy, or SLIT as allergists call it, is the hot topic in the allergy world. Sublingual is the medical word for “under the tongue”. Commonly known as “allergy drops”, SLIT offers the promise of needle-less therapy that can be done at home. We know a fair bit about SLIT at this point, but there is still much we don’t know as well.

SLIT has been around since the mid-80’s. It takes the same idea as traditional injection immunotherapy and simply applies a different route of administration. The drops are held under the tongue for a minute or two the swallowed. There is very little risk of systemic reactions, though local oral itching and burning are common at first and diminish over time.

I would describe my feelings toward SLIT as cautiously optimistic. Though there are numerous trials supporting SLIT’s effectiveness, most of the positive studies come from a small cadre of physicians in southern Italy and most of them are small studies. Other researchers in northern Europe, Britain and the U.S. have failed to replicate the findings of the Italians. For instance, the Italians claim SLIT can simply be given a few weeks prior to the allergy season with excellent benefits whereas a large British study took 18 mos to show a difference from placebo.

In the U.S., the allergy mixes, called antigens, are not licensed by the FDA for sublingual use. Because of this, insurance companies will not pay for SLIT as they consider it an investigational therapy. The American antigen manufacturers would love for SLIT to be approved. SLIT requires 10 to 300 times more antigen than traditional injection immunotherapy. This means the antigen manufacturers would sell 10 to 300 times the amount of antigen they are selling now, if not more. A major American antigen manufacturer recently completed a phase II trial utilizing grass pollen extracts which failed to show efficacy. Their explanation was that the grass pollen levels were too low during the trial, which is a valid reason. Nevertheless, it does give one pause.

So, in summary, I think there is adequate evidence to support the use of SLIT as a second line therapy in patients who have a compelling reason not to utilize traditional allergy shots. Our practice has around 50 patients on SLIT currently, and many are satisfied with the results.

Who needs antibiotics for a URI?

Who needs to see an Allergist?

Allergic rhinitis, or hay fever, has a huge impact on individual sufferers and society as a whole. It is the 5th most common chronic disease in the U.S., and Americans pay $3.5 billion annually for allergy care and miss 3.5 million work days every year because of allergies. Allergy sufferers’ quality-of-life scores are generally on par with other chronic illnesses like major depression and rheumatoid arthritis.