Posts by Dr. Aaron Davis, M.D.:

Cedar Fever Is Coming To Town

Comments Off on Cedar Fever Is Coming To Town Written on October 10th, 2014 by
Categories: Allergies, Allergist, Allergy Advice, Allergy Shots, Pollen in Arizona

“Cedar Fever” is a term given to allergies associated with cypress and juniper tree pollen. The scientific family name for these trees is “cypressaceae”. Although these allergies are typically thought of affecting people in Austin Texas and Santa Fe New Mexico, many people are affected each winter in Arizona as well. The common symptoms of Cedar Fever include: sneezing, nasal congestion, runny nose, throat drainage, and itchy, red, watering eyes. Other symptoms, which are easily overlooked, are achiness, fatigue and low grade fevers, hence the name “cedar fever”. Oftentimes these symptoms are attributed to the common flu. Allergies to this type of tree pollen can also trigger asthma.


In Arizona there are many trees which are “anemophilous” or wind born pollinators. The dry warm climate and wind allow these trees to reproduce. Juniper and cypress trees are evergreen trees and come in a variety of shapes and sizes. They can be short or tall and resemble a bush more than a tree.  The easiest way to distinguish between cypress and juniper trees is to look at their cones.  The cypress trees have large round cones, while the juniper tree has “juniper berries”. These trees are not as prevalent down here in the valley; however, as you travel further north, higher altitudes support the growth of pine trees and juniper trees, also referred to as Pinyon-Juniper Woodland. These plants produce pollen that can be carried 40,000 feet up into the atmosphere and can be transferred fifty miles from the source.  Typically the valley’s highest pollination season is in winter, or early December through February.


In summary, if each winter you feel like you have recurrent sinus infections, a cold, lasting flu, or asthma, your symptoms may just be from the native plants of Arizona.   The next time you hear residents of Texas and New Mexico complaining of “cedar fever”, let them know that they are not the only ones who can lay claim to the allergies associated with Cedar Fever.


Eosinophilic Esophagitis, what is it?

Comments Off on Eosinophilic Esophagitis, what is it? Written on August 25th, 2014 by
Categories: Allergies, Allergist, Allergy Advice, Allergy Articles, Allergy Shots
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Lately the media has been paying more attention to food allergies, and for good reason.  Food allergies are increasing in America, and we are not sure why.  One such food allergy issue is eosinophilic esophagitis.  This is a medical condition that occurs when the esophagus becomes inflamed with eosinophils, which are white blood cells associated with allergies.  The inflammatory reaction is most often diagnosed by obtaining a biopsy of the esophagus during a procedure called an esophagogastroduodenoscopy, also known as an endoscopy.  If the inflammatory reaction occurs repeatedly, over time people may experience esophageal spasms, weakening of the LES (lower esophageal sphincter) and possibly structural changes of the esophagus itself.  There are a variety of symptoms that someone may experience with eosinophilic esophagitis, the most common symptoms are explained below.

One symptom is difficulty swallowing.  When the esophagus becomes chronically inflamed it can even spasm and cause food to become lodged or impacted.  This is a quite painful reaction, which may result in the individual regurgitating water and saliva.  Often these symptoms are quite alarming and patients will seek immediate medical treatment in the emergency room.  Fortunately, the symptoms resolve once the food has passed or after it is removed via endoscopy.  Foods that typically become impacted are items that are thick in consistency, such as meat, or items that swell with the introduction of fluid, such as bread or rice.

Other symptoms may occur due to the regurgitation of stomach acid, which result from the LES not working properly.  The LES is a muscle that prevents acid from leaving the stomach and entering the esophagus.  The LES is the reason we can stand on our head and food won’t rush out.  In infants the LES does not work as well as it does in adults.  This is why infants tend to “spit up” after eating.  Inflammation from eosinophilic esophagitis interferes with the LES and allows stomach acids to wash up into the esophagus.  This acid causes burning pain, chest discomfort, regurgitation of food and various other symptoms.

If eosinophilic esophagitis becomes a chronic problem, structural changes of the esophagus may occur.  The most common structural changes are the formation of esophageal rings or strictures.  These rings in the esophagus cause food to  “catch”, and swallowing can be obstructed.   If the strictures become severe, a gastroenterologist will perform a procedure called “dilation”.  The purpose of this procedure is to break or stretch the rings or adhesions and prevent food from becoming obstructed in the esophagus.

In closing, eosinophilic esophagitis can cause a myriad of symptoms and is still under diagnosed.  Food allergies quite often play a major role in eosinophilic esophagitis, and there are ways to test for food allergies with a board certified allergist.  This can include skin testing and blood testing.  If you are experiencing some of these symptoms, talk to your physician or seek an allergist or gastroenterologist who are familiar with this condition and are willing to work as a team with you.


Vitamin D and Allergies and Asthma

Comments Off on Vitamin D and Allergies and Asthma Written on June 8th, 2011 by
Categories: Allergy Advice
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Vitamin D seems to be all the rage these days. You can hear about it around the water cooler at work, in your physician’s office, and store shelves seem to be brimming with vitamin D supplements. Currently, there are several studies that suggest vitamin D may play a role in allergies and asthma, but definitive results are pending.

Research has revealed vitamin D’s role with calcium, and how it affects our bones and parathyroid glands. Vitamin D is important for the absorption of calcium by the intestinal tract. It prevents problems with our bones, such as osteomalacia in adults and Ricket’s disease in young children. This supplement also prevents abnormal function of the parathyroid glands. Finally, we know that vitamin D plays a role in our immune system; however, the specific role is still unclear.

Augusto A. Litonjua M.D. has proposed vitamin D may also protect patients from getting asthma and allergies. Dr, Litonjua’s proposal has inspired others to further research the correlation between vitamin D and allergies and asthma. One such study headed by John Brehm M.D. was CAMP, Childhood Asthma Management Program. CAMP studied over a thousand children with asthma from diverse backgrounds and various locations within the United States. Dr, Brehm reviewed vitamin D levels in the children’s blood. His research revealed that patients with low levels of vitamin D have more severe asthma and more frequent emergency room visits than those with higher levels of vitamin D in their blood. Other studies are finding vitamin D receptors in cells that are associated with the immune system. This is important because asthma and allergies are caused by an overactive immune system.

In summary vitamin D is important for calcium absorption, bone strength and parathyroid gland function. The medical community is interested in learning more about vitamin D’s possible correlation with allergies and asthma. Vitamin D can be naturally produced when our skin is exposed to sunlight. It may also be obtained through our diet. Currently, the recommended daily dose is 400 I.U.’s of vitamin D. Vitamin D can be found in foods high in fat, such as fish, egg yolks. and liver. People can increase their daily dose by eating foods fortified with vitamin D, such as milk and cheese. If you have questions regarding the role of vitamin D and your health, please ask your health care provider.




Tips For Reducing Springtime Allergy Symptoms

Comments Off on Tips For Reducing Springtime Allergy Symptoms Written on March 18th, 2011 by
Categories: Allergy Articles, Spring Time Allergies
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Allergists from the American College of Allergy, Asthma and Immunology (ACAAI) have some tips for reducing allergy symptoms this spring. I thought they were excellent and worth sharing… Enjoy!


1. Wear glasses or sunglasses when outdoors. Covering  your eyes keeps pollen and other irritants away from this sensitive area, which reduces itchiness and redness.

2. Shower and wash your hair before bed.  Cleaning up before getting into bed helps remove pollen from your hair and skin, which reduces irritation. You should also consider keeping pets out of the bedroom if they’ve been outside, as pollen can cling to their fur.

3. Minimize activities outdoors when pollen counts are at their peak. Pollen is typically at its highest point during midday and afternoon hours, so those who suffer with allergies and asthma should avoid going outside during those times of day.

4. Run the air conditioner at home. Leaving doors and windows open is a good way to invite allergens and other irritants inside your home, so there’s no escape.

5. Keep air conditioning and furnace filters fresh. It’s important to change filters every three months and use filters with a MERV rating of 8 to 12.  A MERV rating tells you how well the filter can remove pollen and mold from the air as it passes through.


1. Treat symptoms without knowing what you’re allergic to. You may think you know what’s causing your allergy symptoms, but more than two-thirds of spring allergy sufferers actually have year-round allergies. An allergist, a doctor who is an expert in treating allergies and asthma, can perform tests to pinpoint the cause of your suffering and then find the right treatment to stop it.

2. Spend blindly on over-the-counter medications. There are tons of allergy medications available at the store, some of which can be very effective. But if you’re buying new products all the time, spending a bundle and not feeling better, consult with an allergist who can discuss which options might be best for you. Your allergist may suggest nasal spray or allergy shots, also called immunotherapy. Immunotherapy can actually cure your allergies and keep you out of the drug store aisles for good.

3. Wait too long to take allergy meds. Don’t wait until symptoms kick in and you’re already feeling bad to take allergy medication. Instead, prepare by taking medication that has worked for you in the past just before the season starts. Pay attention to the weather: When winter weather turns warm, pollens and molds are released into the air. Start treatment prior to the warm up.

4. Hang clothing or laundry outside. On a clothesline, fabric can collect pollen, which is an allergy trigger. Instead, use a drying machine to reduce these allergens.

5. Eat produce and other foods that might aggravate sniffles and sneezing. If your mouth, lips and throat get itchy and you sniffle and sneeze after eating certain raw or fresh fruits or other foods, you may have “oral allergy syndrome.” The condition, which affects about one third of seasonal allergy sufferers, occurs in people who are already allergic to pollen when their immune system sees a similarity between the proteins of pollen and those of the food, and triggers a reaction. If you are allergic to tree pollen, for example, foods like apples, cherries, pears, apricots, kiwis, oranges, plums, almonds, hazelnut and walnuts may bother you. Cooking or peeling the food may help, but you should talk to an allergist.





Comments Off on Hives! Written on March 1st, 2011 by
Categories: Allergy Advice, Allergy Articles, Hives

Hives are a very common condition that our clinic sees on a daily basis; up to 20 percent of the population will have hives at one time or another in their lifetime.  Hives have been around a long time, documented as far back as early Egypt on papyrus.  Hives, (sometimes called welts) are known by their Latin name “urticaria”.  Hives appear as itchy red raised bumps which resemble mosquito bites, but hives may also have clear centers and look like irregular rings.   The itching from hives can cause so much discomfort individuals may not be able to sleep at night or have difficulty in concentrating.  In addition to itching, hives may also feel warm or burn.  In certain situations, hives will come and go as they please with little rhyme or reason.  Hives may also form in the deep tissues and cause a dramatic swelling of the body called “angioedema”.  Typical locations of angioedema include the lips, eyes, tongue, fingers, toes and even genital areas.


Hives and angioedema can arise spontaneously, and may occur with obvious triggers.  Obvious triggers include touching an allergen (something we are allergic to) causing hives.  Contact with grass, cat or dog dander/saliva and even certain foods are examples of such a “contact urticaria” reaction.  Medications may cause hives if an individual is, or becomes allergic to the medication (for example penicillin, aspirin and ibuprofen).  Virus infections, valley fever and a several other infections may also cause hives.  Physical stimuli such as cold temperatures, pressure, scratching, sunlight, stress and very rarely water can also bring forth hives in susceptible individuals.


Hives are a component of other allergic reactions.  People who have contact sensitivity to different chemicals, lotions, fragrances or detergents will break out in a rash that may also trigger hives.  If an individual with severe allergies to a food will have an immediate and dramatic reaction, this reaction may include hives among other symptoms.


There are two categories of hives, chronic and acute.  Chronic hives last at least six weeks and acute will resolve in less than six weeks.  Chronic hives may last for years, possibly decades causing people to be frustrated and interfere with quality of life.  Research now reveals this chronic condition is due to an autoimmune process known as “chronic autoimmune urticaria.”  This diagnosis is made through a blood test that is available today.


An experienced allergist will obtain a thorough history and physical and order the necessary labs.  Treatment(s) for chronic hives may include anti-histamines, steroids, and avoidance measures.  Preliminary studies have shown a common asthma treatment may resolve hives and minimize side effects of other treatments.  Our practice, associated with Medical Research of Arizona, is currently studying this promising new treatment for hives.  If you are having trouble with hives, consult one of our board certified allergist and sleep well at night.




Allergy Videos

Comments Off on Allergy Videos Written on January 1st, 2011 by
Categories: Allergy Advice, Allergy Videos



The Root Cause of Allergies and Asthma



The Root Cause of Hives



Asthma Drug Delivery: Proper Inhaler Use



How to use an Advair Diskus



Nose Washes with a Squeeze Bottle



Nose Washes with a Neti Pot



3D Medical Allergy Animation



What is COPD



Understanding Asthma



Stinging Insect Allergy



How to Use an EpiPen



Asthma Controler Inhalers