Previous research indicates that women tend to experience
more severe allergic reactions - anaphylaxis – than men. The reason behind this
has remained somewhat of a mystery, however, a new study published in The
Journal of Allergy and Clinical Immunology suggests estrogen could be to
blame. Researchers from the National Institute of Allergy and Infectious
Diseases have explored sex-dependent differences in a mouse model of
anaphylaxis to explore how female sex hormones, estrogen, may be involved.
In this study, anaphylaxis was induced in both female and
male mice by using histamine, as well as Immunoglobulin E (IgE) and
Immunoglobulin G (IgG) receptor aggregation. Anaphylaxis was assessed by
monitoring body temperature, release of mast cell mediators, and lung weight.
Researchers were able to observe that female mice experienced
anaphylaxis that was more severe and lasted longer compared to their male
counterparts. This enhanced severity was eliminated after pretreatment with an
estrogen receptor antagonist or ovariectomy. They found that estrogen
influenced blood vessels and enhanced the levels and activity of endothelial
nitric oxide synthase (eNOS), an enzyme that drives anaphylaxis. When eNOS
activity was blocked, the gender difference disappeared. When they blocked
estrogen in female mice, this decreased the severity of their allergic
This study demonstrates a link between estrogen and eNOS in
severe allergic reactions in female mice. The results may shed light on why
women have more severe allergic reactions than men, however, further research
is needed to determine whether there is a similar effect in humans.
Estrogen increases the severity of anaphylaxis in female mice
through enhanced endothelial nitric oxide synthase expression and nitric oxide
production, Valerie Hox, et.al.,The Journal of Allergy and Clinical
Immunology, doi:https://dx.doi.org/10.1016/j.jaci.2014.11.003, published 29
Partners physician would likely respond to the above statement with a cautious
“maybe.” Hives, like many of the responses of the body, can be caused by
many stimuli, not just allergies. Take, for instance, the similar example
of sneezing. Sneezing is a common allergic symptom; however, we all know
that non-allergic stimuli can cause sneezing, from infections due to the common
cold to irritants in the air (pepper, for example). In a likewise fashion,
hives can be due to allergic and non-allergic causes.
Partners doctor will take a careful history and perform a thorough examination
when considering whether your hives are due to an allergic reaction. Be
prepared to answer questions on how long your symptoms have lasted, any recent
exposures to new foods or medications, and whether you have experienced any
If you have had
hives almost daily for six weeks or more, your allergist may use the term
“chronic” to describe your condition. Hives lasting less than six weeks
are called “acute”. The distinction between “acute” and “chronic” is
important, as acute hives are more frequently associated with identifiable
causes. If supported by the details of your history, allergy testing may
be helpful in identifying causes of acute hives.
non-allergic conditions have been reported to be associated with chronic hives,
including various infections, connective tissue diseases, thyroid dysfunction,
and endocrine disorders. If your symptoms do not readily suggest one of
these conditions, extensive laboratory testing is not typically warranted or
necessary. Extensive testing is not cost-effective and does not appear to
improve patient outcomes. In light of an unremarkable clinical history
and physical examination, laboratory evaluation and allergy testing rarely identifies
a cause for chronic hives.
Hives can be
incredibly uncomfortable and frustrating. Hives typically improve with a
regimen of antihistamines, regardless of the cause. For cases of chronic
hives that do not respond to antihistamines, alternative treatments are
available. A newly approved approach to chronic hives utilizes the medication
Xolair (omalizumab). This medication was initially developed for patients
suffering from moderate to severe allergic asthma, but has shown to be
effective in chronic hives. With your input, your Allergy Partners physician
can decide what testing and treatment options are best for you.
Nobody likes getting a shot, especially children.
However, US health guidelines recommend annual influenza vaccination of
children, especially those with asthma, and including those with egg allergy.
Live attenuated influenza vaccine (LAIV) is an intranasal vaccine administered
via the nose licensed for use in children. However, this vaccine contains egg
protein and it is currently suggested that it not be used on children with egg
allergy. Furthermore, North American guidelines recommend against its use in
children with asthma. Thus, asthmatic or egg allergic children receive a
traditional flu shot.
In a study recently published online by The Journal of Allergy and Clinical
Immunology (JACI), Turner and colleagues present the results of the
SNIFFLE-1 Study. In this study, 433 doses of LAIV intranasal flu
vaccine were administered to 282 children with egg allergy. Two thirds of
the children also had a physician diagnosis of asthma/recurrent wheezing and
41% had experienced a prior anaphylactic (severe allergic) reaction to egg.
The study found that influenza vaccination using LAIV was safe in egg-allergic
children – including those with a prior history of anaphylaxis – with no
systemic allergic manifestations seen. Eight children experienced mild short
lived symptoms, which may have been due to an IgE-mediated allergic
reaction. However, noting the intranasal reaction thresholds to egg, the
authors suggest these reactions were not likely to have been caused by egg
protein and were probably due to other ingredients in the vaccine.
Importantly, in those children with a history of asthma or recurrent wheezing,
there was no significant increase in respiratory symptoms requiring medical
treatment in the 72 hours following vaccination with LAIV. This suggests that
the current guidelines may be unnecessarily over-restrictive in terms of this
vaccine’s use in patients with asthma or egg-allergy. This study may help lead
to changes in the current guidelines and make an annual flu vaccine more
pleasant for kids with asthma and egg allergy.
have become an increasing public health issue. Recent studies now indicate that
nearly 1 in 13 children are diagnosed with food allergy. Food allergies are
triggered when the immune system make a special type of antibody, called IgE,
directed against foods. On re-exposure to the food, the IgE antibody can
trigger severe, even life threatening allergic reactions.
The diagnosis of
food allergy is typically done through a combination of a detailed medical
history coupled with specific food allergy testing. Classically, such testing
is through skin prick testing where a small amount of the food is applied to
the skin and the skin is then pricked with a small sterile probe, allowing the
liquid to seep under the skin. After about 20 minutes, a hive (a bump similar
to a mosquito bite) may form indicating allergy. More recently, a blood based
test commonly referred to as RAST or Immunocap testing has grown increasingly
popular. Unfortunately, these blood based tests can be overly sensitive and
have false positive results. This can lead to misdiagnosis of food allergy
which leads to unnecessary food avoidance, unnecessary medication
prescriptions, and increased cost.
In a recent
study in Journal of Pediatrics, Bird and colleagues at the University of
Texas Southwestern Medical Center and Dell Children’s Medical Center in Dallas
reviewed the charts of 797 patients referred for evaluation of possible food
allergy. They selected patients in whom the primary care provider had ordered a
standard panel of food-specific IgE tests. Such a panel was done in 284 (35%)
of all patients. Of these, only 90 patients (32.8%) had a history that
warranted such testing.
altered in 126 of patients based on the initial testing. Of these, 72 did not
have histories suggestive of food allergy and all of these individuals were
found to not have food allergy. In total, 112 (88.9%) of the 126 patients who
were avoiding foods were able to reintroduce at least one food. It was
estimated that the cost associated with those patients whose history did not
warrant food allergy testing was $79, 412.
The diagnosis of
food allergy hinges on a detailed history and physical exam. Food-specific IgE
testing is a vital tool used to confirm food allergy. This study, however,
highlights that panels of food specific IgE tests have little utility as a
screening tool. Such panels often result in the over-diagnosis of food allergy.
A ‘positive’ test does not automatically translate into clinical food allergy,
as a significant proportion of individuals with a positive test are not
Partners physicians are Board Certified Allergist-Immunologists. This means
that they have undergone two to three years of specialized training in the
diagnosis, treatment and management of allergic diseases, including food
allergy. They have expertise in the interpretation of food allergy test results
and are equipped to offer food challenges which are the definitive test for the
diagnosis of food allergy. If you are concerned about food allergy, contact
your Allergy Partners physician.
Source: Bird JA,
Crain M, Varshney P. Food Allergen Panel Testing Often Results in Misdiagnosis
of Food Allergy. J Pediatrics 2014:166(1):97-100.
Sleep apnea is a common disorder in which you have one or more pauses in
breathing or shallow breaths while you sleep. Breathing pauses can last from a
few seconds to minutes and they may occur 30 times or more an hour. Typically,
normal breathing then starts again, sometimes with a loud snort or choking sound.
Sleep apnea usually is a chronic (ongoing) condition that disrupts your sleep.
As a result, the quality of your sleep is poor, which makes you tired during
the day. Sleep apnea is a leading cause of excessive daytime sleepiness. More
importantly, sleep apnea can increase your risk of high blood pressure, heart
attack, stroke, diabetes and obesity.
There is evidence
suggesting that a relationship exists between asthma and obstructive sleep
apnea. A recent study in the Journal of the American Medical Association
investigated if having asthma increased the risk of developing obstructive
sleep apnea (The
Association between Asthma and Risk of Developing Obstructive Sleep Apnea. JAMA
2015: 313 (2):156-164.).
This study used a population that consisted
of adults who had overnight sleep studies completed at 4 year intervals
starting in 1988 (The Wisconsin Sleep Cohort Study). Asthma and additional
information was assessed during these studies through March 2013.
The results found that participants with
bronchial asthma had a significantly higher incidence of developing obstructive
sleep apnea (27%) at their first 4 year follow up interval sleep study, versus
16% of the participants without asthma who developed sleep apnea at that
interval. Using all 4 year interval studies, there was also a significantly
higher percentage of participants with bronchial asthma who developed
obstructive sleep apnea (27% ), versus 17% of non-asthmatic participants who
developed obstructive sleep apnea.
In summary this study found that
preexistent asthma was a risk factor for an asthmatic patient developing
clinically relevant obstructive sleep apnea over a 4 year period. It was also
found that the longer the time a patient had bronchial asthma, the more likely
that the patient would develop obstructive sleep apnea.
Therefore, obstructive sleep apnea should
be considered in asthmatic patients with symptoms suggestive of sleep apnea,
and especially those patients who have a history of long-standing bronchial
asthma. Symptoms of sleep apnea include snoring, choking or gasping while
sleeping, daytime sleepiness, or not feeling well rested after sleep.
Identifying and treating obstructive sleep apnea in asthmatic patients has been
found to be beneficial, since another study has shown that treating obstructive
sleep apnea in patients with asthma leads to improvement in asthma symptoms,
improved air movement and improved quality of life.
If you think you have a sleep problem, consider keeping a
sleep diary for 1 to 2 weeks. Bring the diary with you to your next doctor’s
appointment. Write down when you go to sleep, wake up, and take naps. Also
write down how much you sleep each night, how alert and rested you feel in the
morning, and how sleepy you feel at various times during the day. This
information can help your doctor figure out whether you have a sleep disorder.
SLIT is an alternative method of allergen desensitization in the management of atopic conditions such as asthma and allergic rhinitis, which does not involve a series of injections. The protocol for SLIT involves an allergist determining a patient’s sensitizing allergens, typically by skin testing, followed by small doses of these allergens placed under the tongue daily in the form of tablets or drops. This causes a decrease in the body’s natural production of specific allergic antibody, called IgE.
Though SLIT is widely accepted and standard in Europe, not all SLIT therapy is approved in the US by the Food and Drug Administration (FDA). A tablet form of SLIT for patients with grass and ragweed allergy (GRASTEK, ORALAIR, RAGWITEK) has been FDA approved and is currently available for physicians to prescribe. While yet to be approved by the FDA, sublingual drop therapy formulated by your Allergy Partners physician is available for “off label” use.
Does it Work?
There is mounting evidence that SLIT is an effective treatment strategy in the management of allergic conditions. A recent systematic review in the Journal of the American Medical Association states: “The overall evidence provides a moderate grade level of evidence to support the effectiveness of sublingual immunotherapy for the treatment of allergic rhinitis and asthma, but high-quality studies are still needed to answer questions regarding optimal dosing strategies.”1Though evidence supports SLIT being more efficacious compared to some traditional treatment strategies, it is very clear that subcutaneous injection immunotherapy (allergy shots) is favorable to SLIT in reducing allergy symptoms.
What Are the Side Effects?
In general, SLIT is well tolerated. Patients may have oral itching or mild tongue swelling after the first 3-4 doses. However, these symptoms typically subside. Other potential side effects include: trouble breathing, throat tightness, throat swelling, dizziness, rapid heartbeat, severe stomach cramps, vomiting, diarrhea, and severe flushing of the skin. As there is risk for anaphylaxis, all patients on SLIT therapy should have access to an epinephrine pen and be trained on its use and the first dose of SLIT is administered in a physician’s office.
Is it For Me?
There are certainly advantages to SLIT. Published data does demonstrate clinical efficacy and you can expect to see improvement in your allergy symptoms. For patients with busy schedules, SLIT makes immunotherapy less cumbersome as treatment can be given at home. For children with “needle phobia,” SLIT provides an alternative option to avoid weekly injections. Although allergy shots are the most efficacious form of immunotherapy, there undoubtedly is a role for SLIT in the management of allergic disease. Talk to your Allergy Partners physician about whether SLIT is the best option for management of your allergy symptoms.
1. Sublingual immunotherapy for the treatment of allergic rhinoconjunctivitis and asthma: a systematic review. JAMA. 2013 Mar 27;309(12):1278-88.
Food allergy is estimated to affect 5 to 7% of infants and 1 to 2% of adults. Currently there is no cure for food allergy and patients must adhere to a strict regimen of dietary avoidance of foods to which they are allergic. Despite the best of intentions, accidental exposure to food allergens remains a significant cause of allergic reactions. To avoid such exposure, food allergic patients and their families rely on food package labels to identify possible triggers.
The Food Allergy Labeling and Consumer Protection Act of 2004 requires packaged foods sold in the United States to clearly list the eight primary food allergens in plain English on the ingredient label. These 8 foods are milk, egg, wheat, soybean, peanut, tree nuts, fish and shellfish. However, for foods that may accidentally contain small amounts of allergens- such as being produced in a factory that handles the allergen- precautionary labels may be applied to food products as well. Such precautionary labeling is neither consistent nor regulated. Food allergic patients have varying levels of tolerance to allergens and such precautionary labels could lead to confusion and unnecessary risk taking behavior.
In January, Medical News Today reported on a study published in the Journal of Allergy and Clinical Immunology (January 2015) by the research team led by Clare Mills, PhD of the Institute of Inflammation and Repair at the University of Manchester in the UK. Researchers sought to better define the threshold doses of 5 major food allergens (peanut, hazelnut, celery, fish and shrimp) in a European population. What researchers were able to demonstrate was that for these foods there is threshold dose below which only 10% of allergic subjects will react. Though more research is needed, such new data could help better identify allergen doses that are safe versus those doses which may trigger a reaction. This information would help improve patient safety through refined product labeling.
These new findings highlight how essential it is for patients with suspected food allergy to be evaluated by an allergist who will not only assess but help minimize the risk for future food reactions.
1. “Study identifies levels at which five foods may trigger allergic reactions” Medical News Today. January 2015.
2. Mills C et al. How much is too much?: Threshold dose distributions for 5 food allergens. J Allergy Clin Immunol 2014, published online January 2015, abstract.
Our office will be opeing at 10 am tomorrow 3/6/15, please continue to check our website and facebook page for any changes.
Due to inclement weather both our Fredericksburg and Stafford offices will be closing at 1pm today.
Peanut allergy can result in severe, and at times fatal, allergic reactions. Unfortunately, peanut allergy has become more and more common over the years. A new study, however, gives hope that early interventions may decrease the risk of developing peanut allergy.
A recent study published in the New England Journal of Medicine suggests that early exposure to peanuts helps to prevent peanut sensitization in high risk children. The study was performed in response to the significant increase in the incidence of peanut allergy worldwide, especially in westernized countries, such as the United States. The most recent recommendations by the American Academy of Pediatrics (AAP) came in 2000, in response to outcomes from infant feeding trials conducted in Europe and the United States. At that time, the AAP recommended refraining from introduction of peanuts to children until age 3. Despite this recommendation, the incidence of peanut allergy continues to rise, and in 2008, the AAP retracted its recommendation due to insufficient evidence. Since that time, multiple observational studies have found that early introduction of peanut protein, as well as cow's milk and egg, result in decreased incidence of these food allergies.
In a new study by Du Toit et al., Learning Early about Peanut Allergy (LEAP), investigators studied over 500 infants at high risk of peanut allergy (severe eczema, egg allergy, or both). Half of the children were randomly selected to consume peanuts and the other half, to avoid peanuts. At age 5, the children underwent peanut challenge to determine if they were allergic. Results indicated that the prevalence of peanut allergy in the peanut-avoidance group was significantly higher at 17.2%, compared to 3.2% in the group that consumed peanuts.
The trial went on to compare two groups: one group of infants with skin prick test (SPT) that was initially negative to peanut, and another with mildly positive results (wheal of 1-4mm). Infants with a wheal of >4mm were excluded from the study (about 10%). In infants with an initially negative SPT, prevalence of peanut allergy was 13.7% in the avoidance group and 1.9% in the consumption group. For infants with mildly positive SPT, the prevalence of peanut allergy was 35.3% in the avoidance group and 10.6% in the consumption group.
Although many questions still remain, early testing of infants at high risk for peanut allergy in the first 4-8 months of life, along with early introduction of peanut protein or in-office peanut challenge may have the potential to prevent peanut allergy in the future.
Allergy Partners’ board certified allergists are experts in the diagnosis and treatment of food allergies. If you have questions regarding food allergies, contact your local Allergy Partners physician.
Welcome to our blog site! Stay tuned to get the latest news. We will share tips and techniques for living with and managing your Allergies & Asthma. We look forward to sharing useful resources with our patients!