Why Am I Short of Breath?

Few experiences are more frightening than not being able to breath. We give little thought to the dozen or so breaths we take each minute of our lives …until there is not enough. And then, If our supply of air is threatened for even a moment, we cannot think about anything else. 

Shortness of breath is one of the most common complaints of patients coming into our office for an evaluation and can have many causes.  Our job is first to find out the cause. Once we know this, we can focus on the proper treatment.

Most people with breathing discomfort will fall into one of two groups: those with a lung problem and those with a heart problem.

Lung: “The Bellows”

All living things move and grow and both require energy.  Food is taken in, digestion converts complex food materials to chemical fuel (usually glucose) .  The fuel is burned in the presence of oxygen to produce high-energy chemicals that can be used by run the machinery of life.  The by-product of this process is water and CO2. Respiration is the process of  getting oxygen into our bodies, transporting It to working tissue and then picking up and carrying away CO2.  Oxygen is absorbed by the hemoglobuin in our red blood cells as they move through the tiny capillaries in our lung.  The empty red blood cell pick up the waste C02 and carry it back to the lungs to be released with each exhalation into the atmosphere.

The lung has two parts:  the airways and the alveoli.  The airway begins as a single big pipe (the trachea) and then, like the branches of tree, becoming progressively smaller until at the end, less than 1 mm in size, they bud into a collection of balloon-like airsacks called the alveoli.  The alveoli are constructed of elastic fibers that stretch to fill up with air when we inspire and contract to expel the air when we breath out.

The smaller airways (bronchioles) are dynamic and can dilate or constrict to increase or decrease the flow of air.

The alveoli are surrounded by tiny capilaires filled with red blood cells that soak up the oxygen and drop off the CO2. 

Lung Diagram

Inspiration occurs by expanding the ribcage and flattening the diaphragm creating a vacuum and a rush of inflowing air. When the muscles of the ribcage are relaxed, the elastic alveoli sqeeze the air out.


The Heart and Blood Vessels: The Pump

The  right side of the heart recieves oxygen poor and CO2 rich blood from tissues and pumps it through the lung where the C02 is dropped off and oxygen picked up.  The oxygen rich blood fills the left side of the heart where it is pumped throughout the body.  

Breathing Sensors

When the tisses in our body are working hard, such as when we exercise,  we produce more CO2 and the blood becomes more accidic. Specialiszed sensors, located in the big arteries of the neck and chest as well as the brain monitor changes in the amount of oxygen, C02 and acid in the blood.  When these sensors sound the alarm, the muscles of the chest and the diaphram are stimulated causeing us to take deeper and more rapid breaths.  The heart is stimulated to beat faster and stronger.  The firing of these alarm sensors also stimulates our conscious centers, making us feel  uncomfortable short of breath”until the oxygen, C02 and acid levels return to normal.

Now that we have the basic physiology down, In my next post, I will review the things that can go wrong to make us feel short of breath.

Asthma and COVID-19: What Is The Risk?

Are Asthmatics at High Risk

Since the beginning of the COVID-19 pandemic, our patients have asked if having asthma places them in the “high risk” group, those that are more likely to become infected with the virus and if they get sick, to have a severe illness leading to hospitalization, respiratory failure and even death.

There is no evidence of increased risk of infection with COVID-19 in asthmatics and asthmatics are not more likely to die from COVID-19. 

Early on in the pandemic, some experts did warn about the theoretical risk that those with asthma could catch the virus more easily and have a more severe illness if infected.  Now however, as more data from around the world has become available, it is clear that there is no evidence of increased risk of infection with COVID-19 in asthmatics and that asthmatics are not more likely to die from COVID-19. 

Are Steroids for Asthma Safe?

Another misconception is that steroid use is dangerous if you become infected with COVID-19.   There is no evidence that steroid use, in any form, used for the prevention and treatment of asthma, increases the risk of infection with COVID-19 or will make an infection more severe.  Actually, the opposite is true.  Asthmatics are more likely to get into trouble if they become infected with COVID-19 when their asthma is poorly controlled because they have not been taking there medications.  In fact, inhaled and oral steroids should be used to prevent and treat an asthma attack, even in patients with COVID-19.    

The bottom line is that all asthmatic should make keeping their asthma under good control through regular use of their preventive medications a top priority.  Doing this will keep you from joining the “high risk” group. 

Plantago ovata 1

Desert Laxative

When I first moved to Arizona from New Orleans where I was finishing training at Tulane, I began to familiarize myself with the local weeds, trees, and grasses that were important causes of allergy problems in the Southwest.  Some plants were on every local allergist’s list of important allergenic plants, and although some of the names on the list – like Oak and Ragweed – were very common, the Arizona varieties looked very different from their southern cousins.  It took a while, but in time I became familiar with all of the plants on the list.  There were a few however, that had me stumped.

Most of the Arizona allergists I knew had English Plantain (Plantago lanceolata) on their list of important allergenic weeds and yet after years of hiking around,  I never saw anything that looked like the delicate pictures of this weed in the books.

English Plantain Illustration

In fact, English Plantain is prevalent around the eastern coastal states, the Northwest, and California where it an important allergen – but not in the deserts of Arizona. So why is it on the list?

The Elusive Plantain

After an unusually rainy winter this year, the desert bloomed as I have never seen it before. The usually brown hues of South Mountain were transformed into a carpet of green.  One morning when out riding my bike,  I noticed a vaguely familiar-looking weed growing on the rode side of the new Chandler extension in Ahwatukee.  I took a few pictures and collected samples to make a pollen reference. Sure enough, it seemed to be the elusive plantain.

Plantago ovata 2
Plantago ovata Ahwatukee, Arizona

This was not English Plantain but a close cousin Plantago ovata.  This variety of plantain is only found in the Southwestern United States and has a number of common names including Desert Indian Wheat. It has been used by the Pima Indians for food and medicine for millennia.

The seeds of Plantago ovata are a common source of psyllium which is used in the manufacture of bulk laxatives and has been a cause of occupational allergy and asthma in workers exposed to the plant.  

psyllium Metamucil
psyllium Metamucil

In Phoenix, the plant appears briefly during the spring, particularly after a wet winter, contributing to the display of desert wildflowers… and to the spring allergy season.

Coronavirus Update

As the global and local effect of coronavirus (COVID-19) continues to evolve, our practice is firmly committed to the health and safety of our patients. We are closely monitoring the changing situation and complying with recommendations from the CDC and The Arizona Health Department.    In addition, we are implementing the following change to our usual operating procedures:                                

Before Coming to the Office

  • If you have had a fever (temperature above 100) within the past week, do not come to the office. Call our office for further instructions.


  • All patients and family members coming to our office will be asked about symptoms, travel, contacts, and have their temperature checked before entering the office.

Social Distancing

  • We will limit the number of patients in our waiting room at any given time to 10.
  • We ask that no more than 2 family members accompany a patient into the office.
  • To minimize the time in the waiting room, all patients with an appointment to see the doctor will be taken immediately to an exam room after checking in.


  • To reduce the need for travel and visits to the office, we are now offering secure, video-based appointments with Dr. Millhollon
  • Weekend and evening appointments are available
  • Please call our office for more information.

Allergy Immunotherapy and Biologic Injections

  • After the initial screening, patients will go to the injection room as usual
  • After your injection, you may wait in the courtyard or waiting room with the goal of maintaining at least 6 feet from any other patient with no more than 10 patients in the waiting room.
  • After your wait time, you may come to the outside window to have your arm checked and indicate that all is well before leaving.

Stay Healthy

At this time, the risk of serious illness from coronavirus infection in Arizona is small. However, the risk is greater for some groups including the elderly and those with chronic health problems including asthma and immunodeficiency.

Like all viral respiratory infections, Covid -19 can trigger an asthma attack. Keeping your asthma under good control should, therefore, be a high priority – as always but particularly at this time. This includes taking your preventative medications daily as prescribed, reviewing your asthma action plan, and making sure all medications are available and up-to-date. Patients who take oral steroids such as prednisone daily are also at increased risk. These high-risk groups need to be particularly vigilant about virus avoidance measures such as regular hand washing and avoiding unnecessary exposure to large groups of people.

If you have any questions, please do not hesitate to contact us.

Arizona Sun

Heat and Sunlight Allergy in Arizona: Yes, It’s a Thing

Can you be allergic to heat and sunlight, two things that Arizona has in extreme abundance?  Unfortunately, the answer is yes.

Allergy to Heat

Normally, people do not break out in itchy hives when spending time in the sun or when exercising although people with chronic inducible urticaria (CIndU) might.  In CIndU, hives and sometimes swelling occurs with exposure to a specific physical stimulus such as heat, cold, scratching, sunlight and even water.

CIndU caused by heat is also called cholinergic urticaria. People with cholinergic urticaria frequently have itching, redness, and small hives whenever there is an elevation in body temperature such as might occur with exercise, taking a hot bath, or sitting in a sauna. The rash can also be triggered by emotional stress or eating spicy and hot food. The trunk, arms, and legs are most frequently involved and the rash usually lasts from 15 minutes to an hour.

The diagnosis is usually apparent from the history but can be confirmed by an exercise challenge.

Treatment usually begins with non-sedating antihistamines such as Claritin, Allegra, Zyrtec or Xyzal.  Antihistamines alone are frequently beneficial although it may take up to four times the usual dose to get things under control. More resistant cases have been treated with a variety of other medications including Xolair given by injection once a month.

Exercise-induced Anaphylaxis

Exercise-induced anaphylaxis is a more serious form of heat allergy. In this condition patients not only break out in hives but can have difficulty breathing and even lose consciousness from a drop in blood pressure with exercise. In some cases, the severe reaction to exercise only occurs if certain foods, such as wheat or peanut, are eaten before the activity.   A careful exercise challenge can confirm the diagnosis and allergy testing can pinpoint the food allergy component.    All patients with this condition should carry an EpiPen, never exercise alone, and strictly avoid food triggers before exercise.

Allergy to Sunlight

It sounds odd and certainly unfortunate if you live in Arizona, but some people will breakout with hives whenever their skin is in direct contact with sunlight for more than a few minutes. This condition is called solar urticaria.

The hives appear on sun-exposed skin several minutes after exposure to a specific wavelength of light and usually last for less than a day as long as you get out of the sun. Covering up to avoid direct contact with the sun is usually helpful although sunscreen, because it does not block the wavelengths of light causing the problem, is not. Phototesting can not only confirm the diagnosis
of solar urticaria but can identify the specific wavelengths of light causing the problem.

Sensitivity to sunlight can cause several other skin disorders called photodermatitis. These conditions, like solar urticaria, occur on sun exposed skin but typically last longer than 24 hrs.

The only thing worse than being allergic to sunlight and heat while living in Arizona is being allergic to dust –  that is definitely a thing.

Macadamia Nut Ice Cream

Diagnosing Food Allergy: The Food Challenge

Fourteen year old Hanna was at the mall with friends when she discovered she was allergic to macadamia nut.  This fact became clear when she nearly died. She had only taken a few bites of the ice cream with macadamia nut from Cold Stone Creamery.  She had eaten a variety of nuts on numerous occasions without problems, her favorites being almond and hazelnut, but his was her  first time to try this macadamia nut.

By the time paramedics had arrived, she was covered in hives, felt dizzy, had vomited, and could not stand

Immediately her mouth began to burn and after a few minutes her face turned bright red.  She felt itchy all over, her eye lids and lips began to swell and she had a hard time breathing.  By the time paramedics had arrived, she was covered in hives, felt dizzy, had vomited, and could not stand.  The paramedics did not waist anytime:  A syringe filled with epinephrine was jabbed into her upper leg, an IV was started and connected to a larger bag of fluid and she was taken to the nearest hospital.  When she arrived at the emergency room she was feeling better, the hives were clearing and she could breath easier.   She was able to go home after several hours.

Trip to the Allergy Office

She was seen in our office the next week for allergy testing.  A small drop of macadamia nut extract was placed on the skin of her back and gently pricked. After 20 minutes the test was read by measuring the size of any swelling at the test site, the “wheal” as well as any redness or erythema.  The size of the test wheal is compared with a negative (saline) and a positive (histamine) control. A wheal that is 3-4 mm larger than the negative control is a positive test. Hanna’s macadamia test was over 20 mm!

For Hanna, the diagnosis of allergy to macadamia nut is clear.  She has a compelling history of typical allergy symptoms appearing within minutes of exposure and a strongly positive result on allergy skin testing to the allergen in question.  The recommendation is also clear.   No macadamia nuts…EVER. She will also need to carry an EpiPen in case of accidental exposure.  Having it nearby could be life saving.

Now let’s back up a notch.

Let’s suppose Hanna stayed home from the mall that day to study for a test and mom decided to make an appointment with an allergist to talk about Hanna’s itchy eyes and sneezing during the spring.   In this alternate universe, Hanna has never eaten macadamia nut.    During the visit mom mentioned that Hanna complained of itching of the mouth with almonds and hazelnuts when she was a child  but is now eating both nuts fairly regularly without problems.  She would like to check for tree nut allergy though, “just to be sure”.

Allergy testing is completed and the results show strongly positive reactions to spring tree and weed pollen.  Testing to the tree nuts showed an 8 mm reaction to almond, 6 mm reaction to Hazelnut, both moderately positive.  Macadamia nut showed a 20 mm skin test reaction.

What is the diagnosis?  Is Hanna allergic to almond and hazelnut?

To answer this important question, we need to start with how we define “allergy”.  The definition of allergy has two parts:

  1. A history of  symptoms (rash, abdominal pain, breathing difficulty, etc.) on exposure to an allergen
  2. A positive result to the suspected allergen on a skin or blood test for allergy

We like to have both to make a diagnosis of allergy. Even though Hanna’s allergy test is positive to almond and hazelnut, she has eaten both frequently without problems.  By definition therefore, she is not allergic to almond or hazelnut.

“Why are the almond and hazelnut allergy tests positive if  she is not allergic.”

There are a number of possibilities but it is most likely that the positive skin test reaction is the result of cross reaction between proteins in the tree nut and very similar proteins in the tree pollen that she is sensitive too. (To learn more about false positive allergy tests, go here.)

Although Hanna understands this explanation (“sort of”) she is still concerned about eating almond and hazelnut now that she knows that the allergy test was positive.  She asks if there is another test that will prove she is not allergic.

In fact, there is….

The Double Blind, Placebo Controlled Food Challenge

The double blind, placebo controlled food challenge is considered the gold standard for diagnosing food allergy.  In this test two foods are prepared, the test food and a placebo food made to look and taste like the test food.  Neither the patient nor those conducting the test  know which is the true food and which is the placebo until after the test is completed.  The use of the placebo removes the chance that symptoms may be related to the patient (or test giver) having symptoms caused by anxiety.

Because of difficulty associated with developing a suitable placebo for every test food, double blind, placebo controlled food challenges are infrequently done.   In stead, open, graduated challenges of the suspected food have become more popular.

Graduated Food Challenge

In this test, the patient is given a very tiny amount of the suspected food while being closely monitored for any signs of a reaction.  If there are no problems after 15-30 minutes, the dose of the food is increased.  This process is continued until a target dose is achieved or until any objective symptoms suggesting a reaction occur.

Allergy testing is always done prior to a food challenge.  If the allergy test is negative or if the patient has a clear history of having eaten the food without problems,  the chance of passing a food challenge is very high.   A food challenge is not recommended in someone who has a clear history of a severe allergic reaction to a food and has a positive allergy test.  Again, this patient is allergic by definition and a food challenge is not needed.

What about the macadamia nut?

More challenging is the question of conducting a food challenge in a patient who shows a strongly positive result on an allergy test and who has never eaten the food.  This is the case with Hanna and the macadamia nut.   Because she has never eaten macadamia nut, there is insufficient information to make a diagnosis of allergy.  On the other hand, the likelihood that she would fail a food challenge test is high because of the strongly positive skin test result.   In this case, the safest recommendation would be for her to avoid macadamia nut.   Although not perfect, cut off values for the size of skin test reaction likely to result in a failed food challenge have been published.

Delayed introduction of allergenic foods because of allergy testing may cause the problem that well-meaning parents are trying to prevent. 

There is increasing evidence that early introduction of allergenic foods to infants is associated with a decrease in food allergy.  For this reason, the unintended consequence of allergy testing of children to foods they have never eaten in hopes that it will be prevent them from having an allergic reaction, is that parents will be afraid to introduce foods that show positive on the test.  Delayed introduction of allergenic foods because of allergy testing may therefore cause the problem that well-meaning parents were trying to prevent.


Sulfa Antibiotic Allergy: Common and Frequently Misunderstood

Sulfa drugs were the first antibiotics

Sulfa drugs were the first chemicals available to treat bacterial infections in humans.  The proper designation for this class of drugs is sulfonamide but they became knows as “sulfa” antibiotics with their widespread use as powders and pills during WW ll.  Although sulfa antibiotics saved lives, their use decreased significantly after the introduction of penicillin because of frequent adverse reactions and emerging bacterial resistance.

Seven Percent of Patients Taking Sulfa Antibiotics Have Adverse Reactions

Approximately 6-8% of patients who take these drugs have adverse skin reactions ranging from a measles-like rash,  hives and swelling, to severe life-threatening skin blistering conditions such as Stevens-Johnson syndrome and toxic epidermal necrolysis.  In HIV- infected patients, the adverse reaction rate to sulfonamide antibiotics is as high as 25 to 50 percent!

For a number of years, the drugs Bactrim DS and Septra DS (which contain two antibiotics: trimethoprim and sulfamethoxazole) were used to treat ear infections in children.  Sulfamethoxazole is a sulfonamide antibiotic.  If patients developed a rash while taking these drugs, they were told that they were allergic to sulfa and should avoid all sulfa drugs in the future.  These antibiotics were widely prescribed and so the number of adults now reporting a history of sulfa allergy is significant.

Sulfa vs Sulfur vs Sulfite vs Sulfate vs…..

As mentioned, “sulfa” is a colloquial designation for sulfonamide antibiotic, but the prefix “sulf” is found in an enormous number of other medications that may contain sulfur, sulfites or bisulfate including penicillin antibiotics, reflux medications, pain medications, blood pressure medications, and a variety of supplements. For example ferrous sulfate is a common medication used to treat iron deficiency.  The chemical structure for the popular diuretic Lasix (furosemide) contains sulfur.   Neither of these medications cross react with sulfonamide antibiotics.

The use of trimethoprim/sulfamethoxazole to ear infections in children has decreased significantly because of an increase in bacterial resistance to these antibiotics.  However, this and other sulfonamide antibiotics are still frequently used to to treat urinary track infections and skin infections with MRSA.

Medications to avoid if you are allergic to sulfa antibiotics

Patients who have had adverse reactions to sulfonamide antibiotics should avoid all sulfonamide antimicrobials including:

  • Sulfamethoxazole, cotrimoxazole
  • Sulfasalazine
  • Sodium sufacetamide
  • Silver sulfadiazine

Other drugs that should be avoided include:

  • Dapsone
  • Darunavir
  • Fosamprenavir
  • Trimethoprim

Drugs that you do not need to avoid if you are allergic to sulfa

Drug class
Drug or compound
Sulfonamide non-antimicrobials
Cross-reactivity is unlikely between sulfonamide antimicrobials and sulfonamide non-antimicrobials
Ibutilide, sotalol
Carbonic anhydrase inhibitors
Acetazolamide, methazolamide, dorzolamide, brinzolamide
COX-2 inhibitors
Diuretics, loop
Furosemide, bumetanide
Glimepiride, glyburide, gliclazide
Diuretics, thiazide
Hydrochlorothiazide, chlorthalidone, indapamide, metolazone, diazoxide
Sumatriptan, naratriptan
No sulfonamide moiety and therefore no cross-reactivity
Sulfate (eg, ferrous sulfate, magnesium sulfate)
Sulfites (eg, sodium metabisulfite)

Source:  https://doi.org/10.1016/j.jaip.2019.05.034

A New (?) Treatment for Peanut Allergy

New Product to Treat Peanut Allergy

The Allergenic Products Advisory Committee of the Food and Drug Administration (FDA) recently voted to recommend approval of a new treatment for peanut allergy to the FDA.  The treatment was previously referred to as AR101 but it is expected to go by the brand name Palforzia,  If as expected,  the FDA gives the go ahead, it will be the first treatment for food allergy approved by the FDA.

A few important points about Palforzia

  1. It is not a medicine.

Palforzia is a capsule filled with a precise amount of peanut powder.  Thats it.

2. Palforzia is a form of oral immunotherapy

Oral immunotherapy is a process of feeding an allergic individual an increasing amount of the food they are allergic to with the goal of increasing the threshold that triggers a reaction. Immunotherapy for airborne allergens such as pollen, mold, and animal dander has been available by subcutaneous injection (allergy shots) for many years and is an effective treatment for seasonal allergies, allergy to pet dander, asthma, and eczema.  Recently, a sublingual (under the tonge) immunotherapy tablet has been approved by the FDA for the treatment of grass and ragweed pollen allergy.  Unfortunately, the grass tablet does not contain Bermuda grass and so is of limited value in Phoenix and other desert communities in Arizona.  This will be the first oral form of immunotherapy to be approved for the treatment of a food allergy.

3. It is not a cure

By increasing the threshold dose of food required to cause a reaction, it is hoped that treatment with Paforzia will decrease the risk of a  life threatening allergic reaction in the event that peanut is eaten by mistake.   It will not allow peanut allergic patients to enjoy a Snickers bar or PBJ sandwich.  With this treatment,  a child who was at risk of a trip to the hospital if he ate half of a peanut,  may be able to tolerate 3-4 peanuts before a severe reaction occurs.

4. It is for life

Patients must take the peanut capsule every day… forever!

5. There are risks

Patients receiving treatment with Paforzia  frequently have allergic reactions to the peanut powder. These reactions range from a stomach ache to anaphylaxis.   For this reason patients on Paforzia must carry self injectable epinephrine at all times.

Weighing the Risks versus Benefits

The challenge for doctors, patients and parents considering this new treatment will be in evaluating the  benefits versus the risks: Does the benefit of having some protection against a life-threatening reaction to an unexpected exposure to peanut outweigh the risk of frequent allergic reactions with the daily treatment?

There is No Such Thing as an Allergy Test

I have been teaching medical students in my office for the past several weeks. These first year University of Arizona students have recently completed a block of studies on the immune system and are spending time in an allergy clinic to learn how memorizing a million obscure names and pathways  applies to the real world of clinical medicine.

Each student spends only half a day with us so there is not much time to impart wisdom. Since this may be their only exposure to the specialty, I have tried to come up with a few important “pearls” for them to take with them.

Here is one of those pearls: “There is no such thing as an allergy test.”

Since we spend a lot of time in our practice testing patients to find out what they are allergic to, this statement is usually greeted by the students with a polite stare as if waiting for the punch line.

First year medical students are understandably a bit nervous when introduced to the real world of doctoring for the first time. They are quite sure of one thing: They do not know very much now and that somehow, over the course of just four years, they will be expected to know practically everything. They are also quite sure that they have no idea how this miracle of knowledge transfer is supposed to happen.

So the students typically smile politely and try not to say anything that would make them look any stupider than they feel. I try to reassure them and suggest that if there ever was a time to ask stupid questions, your first few years of medical school would be it.

The assumption that somehow you should know and that surely everyone but you knows is pervasive but also foolish and can be a serious hindrance to learning. Wisdom begins when we are able to put our pride in our pocket,  acknowledge our ignorance, and ask the stupid question. The other students, contrary to your assumption,  are also quite clueless,  and certain to be relieved when you do.

Back to the point. Why is there no such thing as an allergy test and why is this so important for medical students to learn?

The answer is in the definition of allergy.

Allergy is an adverse condition and symptoms caused by immunologic sensitization and exposure to an allergen.  An allergen, almost always a protein, is the thing (food, animal, pollen, mold, etc) that your immune system decides – arguable by mistake – you need to be defended against.  The resulting production of specific antibodies that react with the allergen is called sensitization.   Without it, you are not allergic.

Sensitization is the part that we learn from an allergy test.

However, having symptoms when exposed to the allergen you are sensitive to is also part of the definition of allergy. Without symptoms, you are not allergic. No matter what the results of an allergy test say.

A diagnosis of allergy cannot be made without a careful  history. In fact, when allergy tests alone are used to make a diagnosis of allergy – which is often the case when patients ask their family doctor to order an allergy test to find out what they are allergic to – the results can be confusing and misleading and even dangerous. In my experience, this is often the case.

Inappropriate diagnosis made on the basis of allergy tests alone have led to unnecessary restriction of foods, elimination of loving pets from the home, disruptive changes at home and at school, and prescriptions for insanely expensive medications such as Epipens.

On their own, blood tests and skin tests for allergy can give falsely positive results as often as 50% of the time. That means that if an allergy test is positive for peanut, and no consideration if given to the patient’s history, there is a 50% chance that the patient is allergic to peanuts and a 50% chance that they are not.

If history is not taken into account to make the diagnosis, an allergy test is about as good as flipping a coin.

Coupled with a thorough and accurate history, however, an allergy test is an essential tool for a making a diagnosis of allergy.

The history – listening! – is the most important skill for a physician to learn. And this is why it is important for medical students to remember: “There is no such thing as an allergy test”.

What is Blooming in Phoenix?

If you have been sneezing and your eyes and nose stinging and watering you might be asking: “My allergies are driving me crazy, what in the world is blooming this time of year?”

And like many, to find out you might google it, put in your zip code and come up with something like this from Pollen.com.

Source: Pollen.com

Source: Pollen.com


Source: Pollen.com

Source: Pollen.com

Seems pretty clear. Your sneezing and drippy nose is being caused by all the pollinating Ragweed, Chenopods (whatever they are), and Sagebrush in your neighborhood.

Perhaps not.

Notice in the map above that Arizona, Southern California, Utah, and Nevada all have the same pollen forecast.  All those regions are pretty much the same aren’t they?  Just like all of Arizona is the same, right?

Perhaps not.

Anyone who has taken a road trip from Phoenix to Prescott, Payson, or Flagstaff in August can tell you that the scenery, not to mention the temperature, changes dramatically as you drive north.  Gliding along on the 1-17, your car is like a time machine driving into the future. You leave the pizza oven called Phoenix with it’s scorched earth landscape and toxic ozone haze, and in two hours you’ve travelled from summer to blissful fall.  The leaves are changing, the air is clear, cool and crisp, (sweater weather) and wild grass on the hill side is swaying in the breeze (along with the ragweed, BTW ).

If you were to continue driving north, past Flagstaff, you would enter yet another ecosystem, the high desert, home to many plants not found in the low desert of South and Central Arizona or around the San Francisco Peaks.  Sagebrush for example is a huge allergy problem in the high desert surrounding Winslow and Page but has minimal presence in Phoenix. (Texas Sage, a common ornamental landscape bush, is not a member of the Sagebrush family.)

Because of the differences in elevation and temperature, the unique ecosystems of Arizona have different pollinating schedules.  Ragweed and Sagebrush may be wreaking havoc in Winslow at the same time that the poor ragweed around Phoenix is just trying to keep from drying up and blowing away.  So a pollen report showing that Ragweed and Sagebrush is high in Arizona is technically accurate but misses the mark for those living in Phoenix.

Some pollen reports seem to group all of the Southwest into the same region.  A report from a pollen counting station located in San Diego will give results that will look very strange if you happen to live in Ahwatukee, even though they are both part of the “Southwest”.

Not Ahwatukee

Not Ahwatukee

To my knowledge, the location of the pollen counting stations for Pollen.com and the weather sites are not listed on their websites.    One of the best sources for pollen levels is the American Academy of Allergy and Immunology.  AAAAI has a rigorous certification process to insure that sights are providing good information. But there is a problem for the Phoenix area.  Below is a map showing the location of certified pollen counting stations in the west.  Notice something missing?

Source: http://www.aaaai.org/global/nab-pollen-counts/western-region

Source: http://www.aaaai.org/global/nab-pollen-counts/western-region

Getting back to the question: “What is blooming in Phoenix”.   This time of year the answer is: “Not much.”

So if pollen counts in Phoenix are low, what is causing all the sneezing, drippy nose, and red, burning, watery eyes in mid August?

For many, this is the problem:

Screen Shot 2017-08-28 at 3.33.21 PM

Source: airnow.gov Phoenix 8/28/2017

Untitled design (2)

High levels of ground level Ozone, common during the hot summer months in Phoenix,  is a significant cause of respiratory symptoms, particularly for those who have allergies and asthma.

But do not feel left out.  Fall will be coming to the desert soon and along with it the seasonal bloom of grass and weed pollen.  And you won’t need a time machine to find it.

Brian Millhollon, MD