“My Worst Allergy Spring Was the Winter I Just Spent in Arizona”: Part Two

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Arizona Ash Flower

While walking my dog several weeks ago, I noticed something unexpected; a number of ash trees in full bloom.   This was unexpected because it was the first week of February and ash trees usually pollinate later in the month.  It was also unexpected because this was near a school in the Foothills of Ahwatukee were the ash trees are supposed to be of a less allergenic variety.   This is in distinction from the Arizona Ash, Fraxinus velutina, which is notorious for it’s prolific production of allergenic pollen. For this reason landscapers have been discouraged from planting Arizona Ash trees for a number of years although they are very numerous in older communities such as the Warner Ranch area as well as old Ahwatukee and Tempe.

Ash trees are in the same family as olive trees, possible the most allergenic tree in Phoenix, and so people who are allergic to one will be allergic to the other

So the ash trees are pollinating a full two to three week early this year, probable because of the warm weather.  This along with large amount of Arizona Cypress and Juniper pollen in the air is creating a very difficult winter for people with allergies.

“My Worst Allergy Spring Was the Winter I Just Spent in Arizona”

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When we think of allergy season, fall and spring comes to mind, but not so much winter.  Yet this December, January, and now into February, patients have been coming into our allergy clinic in the suburbs of Phoenix complaining of some of the worst allergy symptoms all year.  Typical complaints include sneezing, itchy nose, and particularly, very itchy eyes.

Alligator Juniper

Alligator Juniper Payson, Arizona

When patients undergo testing for allergies, many show sensitivity to a number of different allergens such as plant pollen, mold, foods, and animal dander.  However, in the case of the winter allergy sufferers, the majority show sensitivity to only one thing: juniper, or more specifically, Cupressaceae.

The Cupressaceae are a family of evergreen conifers found throughout the world. Arizona is home to a number of native species of cupressaceae including Rocky Mountain Juniper (Juniperus scopulorum), Utah Juniper (Juniperus osteosperma), One Seed Juniper (Juniperus monosperma), Alligator Juniper (Juniperus deppeana) and Arizona Cypress (Cupressus arizonica).

Although Phoenix has a number of ornamental varieties of Cupressaceae used in landscaping, the majority are found at 3000-7000 feet elevation and cover millions of acres surrounding Phoenix on all sides.    When conditions are right, a large amount of cupressaceae pollen finds its way into the valley.  One of the chief offenders is Arizona Cypress which is very prevalent in the higher areas surrounding the valley and produces  pollen November through March.

The pollen produced by the different varieties of Cupressaceae cross react with one another, which means that if you are allergic to one you will be allergic to all.  Mountain cedar (Juniperus ashei) is the leading cause of respiratory allergy in South Texas and affects so many with severe allergy symptoms that it has been given it’s own diagnosis, “cedar fever” .

Oral Desensitization for Peanut Allergy

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This week the Lancet reported results of an oral desensitization study in children with peanut allergy.   Peanut allergic children age 7-16 were gradually exposed to increasing oral doses of peanut over a six month period.  The goal of the study was to achieve a level of desensitization that would allow the children to safely ingest 1400 mg of peanut protein (about 10 peanuts) without symptoms.

At the end of the study period, 62% of the children had reached the target goal and were able to tolerate 1400 mg of peanut protein. 84% were able to tolerate 800 mg of peanut protein, the equivalent of about five peanuts.  In the untreated control group, none of the children were able to tolerate the full dose of peanut protein.  Side effects in the group receiving peanut including vomiting, itching of the mouth and wheezing.  One child had an allergic reaction to the peanut severe enough to require an injection of epinephrine.

This is another study showing that oral desensitization to peanut in peanut allergic children can be successful and relatively safe.  The process does require significant time and effort and is associated with some risk.  It is a procedure that cannot be undertaken at home and requires careful monitoring in an allergy specialist’s clinic or hospital setting.

Is it worth the effort?  Currently, oral desensitization may significantly reduce the risk of a life threatening allergic reaction occurring in a peanut allergic child who is exposed to peanut by mistake.   The procedure is not a cure and does not allow children to enjoy peanut butter or a granola bar without concern of a reaction.

New Immunotherapy Tablet for Grass Allergy: Phoenix Residents Should Read the Fine Print

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Last month, the Allergenic Products Advisory Committee  of the Food and Drug Administration (FDA) voted to approve two sublingual allergy immunotherapy  products.  The FDA will need to give final approval, but this typically follows the advice of its advisory committees.   Both products contain a mixture of pollen from several different grasses commonly found in Europe and the United States.

These would be the first FDA-approved forms of sublingual allergy immunotherapy available in the US.  This is good news because the current use of sublingual immunotherapy is unregulated and therefore of undetermined safety and efficacy. And (often of more importance to patients) sublingual immunotherapy is not covered by insurance.

The bad news is that Arizona is not like Europe (at least from an allergy point of view), nor is it like most of the United States either.  It’s hot and dry. Very hot and dry!  Too hot and too dry for most grasses to survive without constant watering making them too expensive to grow.  The exception to this is Bermuda grass.  Bermuda grass is a heat and drought tolerant grass that has become THE landscaping grass in Arizona.  If it is green and growing on the ground in Arizona during the summer it is Bermuda grass.

Bermuda grass is also very allergenic.  It’s affect on allergy sufferers is so great that a Phoenix ordinance requires that grass lawns and fields be cut short to limit pollen production.   The majority (if not all) of the school playgrounds and sports fields in Phoenix are planted in Bermuda grass which means that kids are particularly vulnerable to grass pollen allergy.   It causes nasal and eye allergy symptoms late spring through fall and is often the trigger for severe allergic asthma attacks.

As important as Bermuda grass is for Arizona allergies, the new grass immunotherapy tablets do not contain Bermuda grass.  Many grasses are grouped into families that produce what are called “cross reacting” allergens.  In other words, even thought the grasses have different names and appearance, our immune system reacts to the pollen as though they were from the same, or very similar, plant.   Bermuda grass however does not have any important close cousins, so none of the pollen in the new grass tablets will help to alleviate symptoms causes by Bermuda grass.

And so. Good news:  A grass pollen tablet for allergies may be approved by the FDA.  The bad news:  It will not benefit you if you live in Arizona.

Progress in the Treatment of Food Allergy

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Immunotherapy is a form of treatment in which small amounts an allergen (pollen, mold, or animal dander) is given to an allergic patient in slowly increasing doses to induce long-lasting tolerance to that allergen.  Immunotherapy is very effective in reducing allergy symptoms and is the closest treatment that we have to a cure. The trick is to be able to safely deliver a substance that a patient is very allergic to (usually a protein) in a manner that allows the immune system time to develop a protective tolerance response without triggering an allergic reaction.  This is routinely accomplished with allergy shots for airborne allergens.  Unfortunately, efforts to treat life-threatening food allergy with immunotherapy without triggering a severe and possible fatal allergic reaction have had limited success.

One of the goals of research efforts in food allergy has been to develop a food look-alike protein – one that can stimulate an effective tolerance response to a food but without the ability to trigger an allergic reaction.   Somewhat like a novice sword fighter  using wooden swords to train until he is experienced enough to handle the real thing.

Recently researchers at The Centre for Plant Biotechnology and Genomics in Spain have developed three hypoallergenic variants of the protein most commonly responsible for allergic reactions to peach (Pru p 3).  Peach is the most common food allergy in Spain and Mediterranean region.   The hope is that these proteins can be used safely as a vaccine in specific immunotherapy to treat patients with allergy to peach for whom the only currently available treatment is life long avoidance.

When You Should Give In To Your Craving for a Snickers Bar

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For the past decade, pediatricians have recommended avoiding peanuts and tree nuts during pregnancy because of the concern that exposure to an allergen at this time might increase the likelihood of the baby having a food allergy, particularly if there is a strong family history of nut allergy.  In spite of these recommendations, not only did the prevalence of allergies fail to decline, but significantly increased during this period, with reported cases of nut allergy tripling from 1997 to 2010   Noting this disturbing trend, in 2008 the American Academy of Pediatricians withdrew their recommendation to avoid any foods during pregnancy to prevent food allergy.

And now, a recent study from Boston Children’s Hospital suggests that eating nuts during pregnancy can actually decrease the risk of allergy in their children.  This study found that the children of moms who ate five or more servings of peanuts and tree nuts a week were less likely to develop allergies to these foods than kids whose mothers ate less than one serving a month.   Pregnant mothers who are allergic to nuts, of course, should continue to avoid these foods.

The results of this study highlights a principle that has become clearer over the past several years as more research is directed at the growing problem of food allergy: withholding exposure to an allergen, particularly in young  children may end up causing the problem that we are trying to prevent.

Is it Allergy or a Cold?

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It’s winter and  the season for runny, stuffy noses, coughing and hacking, and scratchy, sore throats – but not necessarily from allergies.  A question that comes up a lot this time of year is  how to tell the difference between allergies, a sinus infection, and a cold? This is, of course a trick question because a cold IS a sinus infection, technically speaking.  Most cold viruses not only affect the nose and throat but also the sinuses.  What about telling the difference between an allergy attack and an infection?  This can be a challenge at times but there are clues. Typically, allergies cause more itching and rarely pain and mucous is usually clear.  With an upper respiratory infection, drainage can be discolored, the throat can be raw and sore, and you may have a fever.   Also, allergies are not contagious and the fact that 70% of your school or office is home sick with the very same awful symptoms you just came down with might suggest a bug rather than a pollen problem.

This time of year, the primary allergen in the air is pollen from evergreen trees such as Juniper.   So knowing what you are allergic can help us interpret your symptoms.  For example if you are not allergic to Juniper, then respiratory symptoms during the winter are not likely to be allergy related, unless of course your aunt came to visit for christmas and brought her six cats.

You might ask: If it is not an allergy but an infection, then an antibiotic is needed to get better right? Antibiotics are one of the most important discoveries of our modern era.  They have saved millions of lives and turned the nightmare of a devastating infection in a child to a routine affair easily treated by a prescription from the family doctor.  But as miraculous as antibiotics are, they are worthless in the treatment of viral infections, and viral infections are the most common cause of respiratory infection in children and adults.

This however, has not stopped antibiotics from being routinely prescribed for cold viruses.  But how do we know if it is a cold virus and not a bacterial infection and one that would respond to an antibiotic and make me feel better in hours rather than days?  For the most part, a cold causes a lot of uncomfortable symptoms for the first 2-3 days, symptoms plateau around day 4-5, and then slowly improve, usually resolving completely by day 7-10. A cold may lead to a bacterial sinus infection but this rarely occurs in the first week of symptoms. Therefore, the major consensus guidelines for doctors suggest that antibiotics are rarely helpful and not recommended for most patients with typical cases of upper respiratory infection lasting less than 4 weeks.

So how successful are prescribers at following these guidelines? A recent study reported in The Journal of Allergy & Clinical Immunology (JACI),  reviewed the overall national use of antibiotics for adults with sinus infections.  Study data were taken from the National Ambulatory Medical Care Survey and National Hospital Ambulatory Medical Care Survey from 2006-2010, from the U.S. Department of Health and Human Services, and included antibiotic prescriptions associated with outpatient visits made by adults diagnosed with acute or chronic sinusitis. Over the five year study period, sinus infections  accounted for 11% of all primary diagnoses for ambulatory care visits  for which  antibiotics were  prescribed, more than any other diagnosis.  There were 21.4 million estimated visits associated with a primary diagnosis of acute sinus infection, and 47.9 million estimated visits associated with a primary diagnosis of chronic sinus infection.

Antibiotics were prescribed in 86% of acute sinusitis cases, in spite of established clinical practice guidelines recommending against the use of antibiotics for typical acute sinus infections.

No one wants to be sick and when we are ill with a cold we want to get better as soon as possible.  And although the approach: ”better to be safe than sorry and take an antibiotic at the first sign of symptoms rather than wait several weeks to see if it will get better on it’s own” may seem reasonable,  the potential consequences associated with excessive and unjustified use of antibiotics, including allergic reactions, severe adverse side effects, unnecessary costs, and increasing bacterial resistance, cannot be justified.

Both physicians, who want to help and may be afraid to say no, and patients, who may have unrealistic expectations, are to blame for the growing problem of inappropriate antibiotic use.   However, while most of us have grown up in the age of wonder drugs, we are now at risk of entering a new and very scary time called “the post antibiotic era”.    A place were no pill or shot will save us from foes that we have long thought vanquished.

So if you have a cold:  get plenty of rest, avoid public places when possible so that you don’t infect others, and give it time.  If you do not see any improvement in a week or so or if symptoms are getting significantly worse, see your doctor.

Fall Allergy Season

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Although residents of central Arizona are just now beginning to enjoy cooler fall temperatures,  fall allergy season started a bit earlier, sometime around mid to late September.  At this time, following a (hopefully) rainy monsoon season, weeds begin to proliferate and then pollinate in response to the shorter days and cooler nights.  As the monsoon gives way to endless days of snow-bird pleasantness, the dry, calm air slowly fills with dust, air pollutants, and pollen particles.  These chemicals and particles stay airborne longer and travel greater distances, producing the brown haze that we see hovering over the valley.  The meteorological phenomenon know as temperature inversion, where a layer of cool air is trapped beneath a lid of warm air,  adds to the buildup of particles close to ground level.   Add to this growing soup of organic and inorganic nastiness a steady plume of allergenic mold spores released during lawn scalping and other harvesting activities and you have the making of our typical fall allergy season.

A Not-So-Nice Easter Rabbit

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Rabbit Bush (Ambrosia deltoidia), flowering

It’s an unusual name for a weed: Rabbit Bush.  And although it is not clear where the name for this Arizona native variety of ragweed comes from, one thing is clear:  there is a lot of it and it’s a major cause of allergy problems in the spring.  In fact, Rabbit Bush is one of the most prevalent spring allergenic weeds in South Mountain Park and is therefore a significant source of ragweed pollen for Ahwatukee and surrounding areas.   Rabbit Bush (technically Ambrosia (Franseria) deltoidea and also known as triangle bur ragweed or tirangleleaf bursage) comes to life in the spring, particularly if we have had winter rain, producing copious amounts of pollen in the Arizona Sonoran desert from March until  May.   Allergenically,  it is closely related to other varieties of ragweed found throughout the Unities States and will trigger allergy symptoms in patients who have had problems with ragweed before moving to Phoenix.   Other native varieties of ragweed found in the Sonoran Desert include Canyon Ragweed, fond of desert washes, and Desert Ragweed, a smaller but also prevalent ragweed  in the Phoenix area.

Rabbit Bush (Triangular Bursage)

Alien Allergy Attack from the Planet Alpha-Gal

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It sounds like science fiction.  A hideous blood-sucking alien creeps into the bedroom of an unsuspecting victim while they sleep.  With razor sharp fangs the monster begins to feed, injecting a cocktail of chemicals to keep the blood flowing. As the fiend’s venom works it’s way through the body, a frightening change takes hold.  Forever transformed, the victim is doomed to live in fear of pleasures he once enjoyed.

As bizarre as it sounds, this scary story (with a few embellishments) is not science fiction but true.  Here are the unsettling details.

The blood sucking alien is Amblyomma americanum – the lone star tick.  The tick is found primarily in the Southeastern part of the United States, although some believe that its territory may extend further west.  In some individuals, a bite from the tick triggers the immune system to produce antibodies to a substance found in the saliva of the tick called galactose-α-1,3-galactose or alpha-gal.   Alpha-gal is also found in meats such as beef, lamb, and pork and so once a victim becomes “immunized” by the tick bite, eating a steak, for example, can cause hives or even more severe allergic symptoms.

Unlike most allergic reactions to foods, the alpha-gal reaction can occur 4-6 hours after eating meat.  And although a blood test for the alpha-gal antibody is available, it may not be ordered if the connection between a patients severe allergic reaction and eating a hamburger six hours earlier is not made. To make matters worse, patients who have become sensitized to alpha-gal by a tick bite can also have severe allergic reactions to cetuximab, a new medication used to treat cancer.

So far, the only treatment for alpha-gal sensitivity and the resulting meat allergy is avoidance.