With the growing incidence of peanut allergies and the consequent deaths that are often reported on the news, many parents instinctively avoid feeding their children peanuts, assuming that the nuts may cause an adverse and scary reaction in their kids. Even doctors themselves have been known to urge parents to refrain from exposing their babies to peanuts. In 2000, the American Academy of Pediatrics specifically advised parents to avoid feeding their babies peanuts if they were at risk for allergies.
Groundbreaking research conducted over the past five years and finally published paints a new picture of how this intuitive reaction to the growing issue of peanut allergies may actually exacerbate the problem. A study published earlier this year in one of the most respected medical journals, the New England Journal of Medicine reported that exposing babies to peanut products reduces the risk of peanut allergy by 70-86% in those infants at high risk for developing the allergy. The researchers conducting the study, led by Dr. Gideon Lack, presented their findings at the American Academy of Allergy, Asthma, & Immunology (AAAI) conference in Houston in February.
For their study, the researchers tested the idea that regularly eating peanuts during the first year of life would protect against the development of peanut allergies by allowing the immune system to get used to peanuts. The idea for the study stemmed from observations that Jewish children in Israel develop peanut allergies 10 times less frequently than do those in England – and also start eating peanuts much earlier in life, usually before they are a year old. Other motivations for the study were the observations that early introduction of eggs and milk could reduce the development of allergies to these products, often also associated with food allergy. Because these observations were merely observations – and not controlled studies, the researchers wanted to design studies that would allow them to collect meaningful data on the effects of early exposure to allergens on the later development of relevant allergies.
The investigators tested their idea on over 600 infants, ranging from 4 months to 11 months in age. All of these infants were categorized as high risk due to egg allergy, eczema, or both. Approximately half of the children served as a control and were kept away from peanuts, whereas the other half were given snacks containing peanuts three or more times each week until they were five years old. When these children were tested for peanut allergies at the age of 5, only 3.2% of those who ate peanut snacks as babies had developed peanut allergies, compared to 17.2% of those in the group that did not ingest peanuts as babies.
The Food Allergy Research and Education (FARE), an institution dedicated to improving the quality of life and treatment options for those suffering from food allergies, funded this critical research study. Their CEO, James Baker, importantly pointed out at the meeting that the specific timing of initial peanut exposure can significantly impact the likelihood of developing a peanut allergy. FARE also emphasized that these results should not be interpreted to mean that older children and adults who are already diagnosed with peanut allergies should expose themselves to peanuts as a way to cure themselves of the allergy. Though techniques in this spirit are often used therapeutically, in strategies known as immunotherapies, these therapies should be administered and monitored by physicians. While some reports have noted that the World Health Organization (WHO) may be incorrect in recommending that people avoid peanuts if they are allergic, those with peanut allergies do still need to use significant precautions around peanuts. Indeed, the study excluded babies who already showed signs of peanut allergies and so does not offer data on how peanut exposure affects existing allergies.
Though the results of the study on the impact of early peanut exposure to the later development of peanut allergies is striking and highly promising in terms of our growing understanding of peanut allergies and how to protect against them, as with any influential scientific study, the results may open up more questions than they answer. First, will these protected children continue to be protected against peanut allergies later in life and into adulthood? Future research programs aim to track these children to answer that question.
More research will also need to be conducted to determine the optimal exposure dose and timing so that we can best leverage our ability to prevent peanut allergy development and potentially alter guidelines accordingly. For now, the results provide relevant physicians with new data and opportunities for helping their patients avoid the detriments of peanut allergies. With time, we may know enough about the development of peanut allergies to make general recommendations for all parents to follow.
Around 5.4 million people suffer from peanut allergies in the United States and Europe alone. Among those with peanut allergies are millions of children, who, along with their parents, have to deal with the anxiety that comes with these allergies on a daily basis. Peanuts are the biggest culprits for food allergies, with approximately 8% of American children being diagnosed with the allergy. As a society, we are impacted not only by the death that can result from severe allergies and anaphylactic reactions but also by the reduced quality of life associated with dealing with such allergies. The psychological impact of allergies on patients and their families can lead to severe anxiety and antisocial behavior.
The incidence of this specific allergy does not seem to be declining, or even remaining steady. Instead, one study shows that four times more children had peanut allergies by 2010 than in 1997. Another pair of studies, conducted in the Unites States and The United Kingdom, shows that in the past five years, peanut allergies have doubled in kids younger than five years of age.
Today, between 150 and 200 deaths occur each year in the United States as a result of peanut allergies, and around 125,000 emergency room visits result from allergic reactions related to peanuts. It is possible for children to outgrow their peanut allergies, but research suggests that this occurs only about 20% of the time. Though the number of individuals with peanut allergies may not be improving, medical interventions to improve outcomes associated with these allergies seem to be.
A pharmaceutical company based in France has developed a drug (Viaskin Peanut) that may offer a solution for the families impacted by the growing incidence of peanut allergies and improve the economic impact of these allergies on our healthcare system.
Viaskin Peanut, created by DBV Technologies, is delivered in the form of a patch and has been accepted into the United States Food and Drug Administration (FDA)’s expedited approval program. The program, also known as a fast-track program, has less stringent testing requirements for allowing drugs onto the market.
What this means for consumers is reduced waiting time before they can access the drug. Viaskin Peanut should begin Phase III trials this year and become available in the United States in early 2018. It has already been shown that some peanut allergy patients using the patch can eat about four peanuts without suffering allergic consequences.
DBV Technologies is not the only company attempting to create products that can help people who are allergic to peanuts. A United States company, Aimmune Therapeutics, which used to be called the Allergen Research Corporation, is developing a drug, AR101, which would be offered in pill form to desensitize patients to peanuts. Like DBV Technologies, Aimmune Therapeutics has also been accepted into the fast-track approval program by the FDA and plans to start Phase III trials before the end of 2015. Aimmune Therapeutics is also looking into creating interventions for other types of food allergies.
How do these new solutions addressing peanut allergies work? Unlike conventional treatment options, like antihistamines and EpiPens, which aim to reduce the effects of an immune reaction on the body, effectively minimizing the symptoms associated with severe allergic reactions, Viaskin Peanut and AR101 attempt to intervene much earlier along in the process of an allergic reaction. These drugs introduce small amounts of peanut products to the patient, with the goal of desensitizing the patient’s immune system to peanuts. In other words, rather than intervening in the immune reaction, these new drugs are designed to prevent the reaction from occurring in the first place. This strategy for dealing with allergies is known as immunotherapy and is growing in popularity.
The Centers for Disease Control and Prevention (CDC) continues to warn that there is no cure for food allergies. Though the drugs currently being tested and potentially commercialized may improve things for peanut allergy sufferers, they do not claim to cure patients of their allergies or to 100% prevent or stop immune reactions to peanuts. Thus, even if these drugs do soon hit shelves, doctors are likely to continue to recommend that those with peanut allergies take precautions for preventing exposure to these nuts, particularly high-dose exposures. Such exposure can occur, for instance, when prescription drugs containing peanut oil are ingested. Nonetheless, if these drugs are able to minimize the adverse impact of peanut allergies, they are likely to significantly improve millions of lives.
When we think of treating allergies, we often think of pills, inhalers, nasal drops, and EpiPens. However, preventing allergies can be one of the most effective ways to deal with them. Because there are no cures or vaccines currently available for allergies, prevention generally requires controlling one’s environment. For instance, those with food allergies are advised to avoid exposure to problematic foods. Those allergic to indoor and outdoor allergens, such as pollen and dust mites, can also reduce the impact of those allergens on their bodies by employing measures to decrease the levels of those allergens to which they are exposed.
For those with allergies, it has often been recommended that vacuum regularly can improve allergy symptoms by getting rid of allergy triggers like dust mites. Some people suggest keeping windows closed when outdoor allergens are at high levels, minimizing the use of window fans because they pull pollen from outdoors indoors, and to vacuum two or more times per week. Vacuuming is recommended because it is one effective way to keep floors clean, and though not always well recognized, dusty and dirty floors are often primary culprits for indoor allergies. Some people also recommend leaving shoes at the door, to minimize the dirt and dust that accumulates on floors in the first place. Nonetheless, whether shoes are worn indoors or not, dust will naturally occur, and it will need to be removed. Unlike vacuuming, sweeping actually stirs up dust and can therefore exacerbate allergies. Vacuuming is thus recommended as the best way to keep floors clean and allergen-free.
Though vacuuming is a great way to reduce indoor allergens, experts specify that vacuum cleaners will be most effective if they contain a high efficient particulate air (HEPA) filter because these filters are superior at pulling in dust particles. When vacuum cleaners with HEPA filters are used, filters need to be changed approximately every six months and should be changed outdoors so that the trapped dust particles are not released back into the indoor space.
Some recent research studies suggest that rather than improving allergy symptoms, vacuums can in fact make those symptoms worse. Careful inspection of the details of the research reveals that a key issue in whether vacuum cleaners help or exacerbate allergies is the vacuum mechanism – or how the vacuum cleaner works. Some vacuum cleaners, including those with HEPA filters, actually release tiny dust particles and bacteria into the air, which can cause allergies or infections.
A comprehensive study on air emissions of different vacuum cleaners was conducted in Australia, and its results were published in the journal Environmental Science & Technology. After inspecting 21 different vacuum cleaners, the researchers concluded that every single vacuum cleaner released allergens and bacteria into the air. However, there were differences in the extent to which the vacuums did so. Generally, newer and more expensive models polluted the indoor air less than did older and cheaper models. Additionally, though it is claimed that HEPA filters remove 99.9% of bacteria and allergens like pollen from the environment, cleaners with HEPA filters released only slightly less of these substances than did cleaners that lacked HEPA filters.
Despite these findings, experts conclude that vacuum cleaners are still a good way to remove allergens from the environment. Specifically, they claim that a vacuum cleaner would have be extremely old and dirty to do more harm than good in minimizing allergens and reducing allergy symptoms. As far as HEPA filters go, regardless of the precise amount of allergens they are able to remove, it is clear that they remove more of these allergens than are removed without the use of these filters, and it is thus recommended that people continue to employ these filters to get rid of environmental allergens.
When recommending ways to reduce exposure to allergens, there are other recommendations related to cleaning as well. For instance, living in homes with hard wood floors is recommended over homes with carpet. For those with rugs in the home, cleaning the rugs weekly to remove dust and dirt particles can significantly improve allergy symptoms in the home. In addition, using microfiber, rather than paper towels or other types of cloths, can more effectively rid surfaces of irritating dust particles. Because microfiber cloths have small microfibers, they are able to cling to dirt and dust particles in small areas or cracks, which is difficult to achieve with other types of cloths. An added benefit is that to achieve good results, microfiber cloths can be used on their own, or with water, rather than with chemicals that can themselves act as irritants or allergens.
When microfiber cloths are used, it is critical to dust past the end of surfaces, or else dust and dirt will accumulate at the edges of surfaces that are being cleaned. One common suggestion for microfiber cloths is to use them after showering to clean surfaces in the shower and bathroom. This practice reduces moisture and prevents the growth of mold and mildew, which are common allergy triggers. Leaving the door open or keeping the shower curtain partially open can also decrease moisture accumulation by allowing air to flow into the shower rather than trapping moisture inside.
For people allergic to environmental agents like pollen and dust mites, reducing the levels of these allergens to which they are exposed can be a highly effective way to manage allergies and allergy symptoms. Vacuum cleaners can minimize the amount of both indoor and outdoor allergens that are present inside, particularly if they incorporate HEPA filters, which are capable of removing these allergens at high rates.
Before puberty, boys tend to suffer from allergies and asthma more frequently than do girls. However, after puberty, these conditions are more common in women than in men. Women who suffer from acute asthma, which is related to allergies, are 60% more likely than men to require emergency intervention or hospitalization. Further, women suffer more frequent and more severe anaphylaxis, which is a potentially fatal severe allergic reaction that can inhibit a patient’s ability to breathe and lead to stroke. Researchers have wondered for years why the sex difference in tendency to experience anaphylaxis exists, and recent research points to a potential role of estrogen.
Estrogen refers to the main female sex hormones, which are critical in female reproduction and menstrual cycles. Estrogen promotes female characteristics, such as the growth of breasts, and also serves a number of critical physiological functions. Estrogen is used medically for a number of purposes, including birth control (it is contained in oral contraceptives), hormone replacement therapy, and the treatment of certain cancers, such as breast and prostate cancer.
Researchers at the National Institute of Allergy and Infectious Diseases (NIAID), which is one of the National Institutes of Health (NIH) published their relevant findings in The Journal of Allergy and Clinical Immunology. The researchers showed that when exposed to allergens, female mice endured longer and more severe anaphylaxis than did male mice. However, when estrogen levels were reduced in female mice, the sex differences disappeared.
To do this experiment, researchers ovariectomized the female mice, meaning they removed their ovaries. Because ovaries produce estrogen, this procedure minimizes the amount of estrogen circulating in female mice’s bodies. They then compared allergic reactions and anaphylaxis in male mice, regular female mice, and female mice lacking ovaries.
To induce anaphylaxis, the researchers used histamine, which is a natural component of the immune system that causes inflammation, combined with immunoglobulins, or antibodies that initiate allergic reactions when stimulated. Not only did the female mice that lacked ovaries display anaphylactic reactions that were more similar to their male counterparts than did non-ovariectomized female mice, but when researchers injected an estrogen hormone called estradiol into these ovariectomized mice, the mice also suffered more severe anaphylaxis. These results point to a clear role of estrogen in promoting more severe allergic reactions.
After recognizing that estrogen is a key player in allergic reactions and in their severity, researchers asked what it is about estrogen that allows it to exacerbate anaphylaxis. A set of experiments then led to the discovery that estrogen enhances the swelling and blood vessel dilation associated with anaphylaxis because it increases the activity of endothelial nitric oxide synthase (eNOS), which is an enzyme that causes these symptoms. When researchers blocked eNOS activity in female mice, they again observed the disappearance of sex differences in allergic reactions and anaphylaxis.
It is important to note that these studies were conducted in mice, and so it is not yet clear whether the findings apply to humans as well. Because neither physicians nor scientists can ethically induce anaphylaxis in human patients, nor can they remove ovaries in human patients for the sake of experimentation, studies parallel to those conducted in mice cannot be recapitulated in humans. However, additional experimentation is likely to help confirm whether these findings in mice do in fact extend to humans.
Though removing the ovaries of mice to understand the impact of estrogen on different physiological reactions is arguably reasonable for scientific research, it is highly unlikely that female patients with severe allergies would want to remove their ovaries or deplete their systems of estrogen. Thus, the finding that estrogen exacerbates allergic reactions helps us understand the difference in reactions in men and women but does not provide a practical treatment option.
It does, however, provide a useful lesson to females with severe allergies. Namely, it is especially important to avoid allergens and to carry an EpiPen when estrogen levels are high. Estrogen levels are high throughout puberty, just before menstruation, or when estrogen is being used for medical purposes. For example, women undergoing hormone replacement therapy following menopause may be at higher risk for anaphylactic reactions than those who do not undergo hormone replacement therapy. On the other hand, parents of young girls can rest assured that when their daughters are pre-pubescent, their estrogen levels are low, making them less susceptible to anaphylaxis than they may be later in life.
However, the finding that estrogen imparts its effect on allergies by specifically increasing the activity of a certain enzyme – i.e. eNOS – provides a more promising route to treatment. For instance, medications may be developed that specifically inhibit the activity of eNOS in those who suffer severe allergic reactions or anaphylaxis.
It is clear that adult women are more susceptible to severe allergic reactions and complications arising from asthma than are adult men. New research helps clarify the existence of sex differences by demonstrating the key role of estrogen in promoting more severe reactions. By increasing the activity of eNOS, estrogen indirectly enhances swelling and inflammation, which are dangerous characteristics of anaphylaxis. Understanding the critical role of both estrogen and eNOS can enable patients to employ more effective strategies to prevent severe allergic reactions and anaphylaxis and also open up doors to the development of more effective allergy treatment options. Specifically, medications that are able to block eNOS activity may be a particularly powerful way to help women with severe allergies experience fewer or less severe anaphylactic reactions.
We often associate weather with our allergy symptoms because certain seasons bring with them specific allergens that trigger our sneezing, runny noses, and wheezing. Often, the causes for our allergies are agents that thrive in certain weather conditions. For instance, mold grows in the winter, poison ivy is rampant in the summer, and pollen fills the air in the spring and fall. However, sometimes it is the weather itself that makes us suffer form allergies.
Specifically, changes in temperature and humidity can cause allergy symptoms like sneezing and congestion, which occur due to swelling that results from changes in the nose’s membranes. These types of symptoms are generally referred to as non-allergic rhinitis. Other weather specific conditions, however, are allergic reactions rather than non-allergic reactions. For instance, cold urticaria is an actual allergic reaction to cold weather.
Those who experience cold urticarial suffer from itching and swelling when they are exposed to cold air. People often get cold urticaria as a result of a viral infection, while others are born with the issue. Though symptoms are usually more annoying than dangerous, severe reactions can cause anaphylaxis and therefore be life threatening, so some patients with cold urticaria are advised to carry an EpiPen. Lucky patients will outgrow the condition and no longer suffer the associated symptoms.
Many allergy sufferers who do not have cold urticaria still feel as though they are allergic to the weather because of the weather’s impact on their allergies. Each season brings with it specific allergens, and transitions between seasons are often when people have the hardest time with their allergies. During winter, indoor, rather than outdoor, allergies are usually an issue. As winter turns to spring, grass and tree pollens becomes more abundant, and spores begin being released by outdoor molds. When summer rolls around, grass pollen is problematic, and mold spores peak in warm regions. Ragweed is a common culprit in the fall.
The nature of weather within seasons can affect how bad your allergies are. For example, wet winters enable trees to produce more pollen, which can exacerbate pollen allergies in the following months. Some proponents of theories of global warming claim that climate change is adversely affecting allergy and asthma levels. They point to the dangerous combination of ozone pollution and pollen as sources of increasing numbers of allergy and asthma sufferers.
This year, talk of a “pollen tsunami” has been popular, with the apparent rise in allergic reactions in the northeastern portions of North America. Experts say that rather than releasing pollen at different times, several tree species are releasing pollen simultaneously, leading to a huge level of pollen production that is causing allergies that are more severe than usual. Given the rise in pollen, those allergic to the substance have been recommended to keep their doors and windows closed to shield them from the allergen this year. Reducing the amount of time spent outside also helps reduce allergy symptoms, as does avoiding regions where pollen is particularly prevalent. After coming inside, removing and washing clothes is another good preventative measure during this high pollen time.
Those who suffer allergy symptoms at different times of year often have customized medication plans that include increasing certain medications during the times of year when they tend to experience allergies or when they are traveling to areas where they are likely to be exposed to the allergens that affect them. Antihistamines are often effective interventions to both prevent and manage the symptoms associated with allergies. Doctors also sometimes recommend using saline solution to clean the nose so as to rid air passages of allergens. In the winter, using dehumidifiers and allergen filters can help with indoor allergies, whereas avoiding problematic areas in the outdoors is often effective during spring, summer, and fall. However, specific medications are often useful for specific allergies, and those who suffer from severe allergies are often advised to carry an EpiPen in case of an emergency.
It was once thought that shielding babies from potential allergens would protect them from developing allergies. However, research has begun to show that those babies who are exposed to allergens and complex combinations of allergens early in life tend to be at lower risk for developing allergies than those who are kept in sterile environments. These findings are likely the result of the working of our immune systems. As allergies are our bodies’ way of responding to a substance that the body deems threatening, exposing the body to foreign agents earlier can potentially reduce the likelihood that the body will perceive those agents as threatening in the future and will instead recognize them as innocuous parts of the person’s environment.
Though varying levels of antigens throughout different months of the year is an unavoidable concept, being aware of when and why certain allergens will be more prevalent can allow you to minimize the impact of those allergies on your health and quality of life. Avoiding allergens and engaging in activities to effectively reduce the levels of those allergens in your environment and to minimize the effects of those allergens on your body can make certain seasons and seasonal transitions less stressful and more enjoyable.
Several allergy drugs are on the market. There are over-the-counter medications and prescription medications that minimize specific symptoms associated with allergic reactions. EpiPens are generally prescribed for those with severe allergies because they can reverse the life threatening anaphylactic reaction that can occur in patients with allergies. EpiPens contain epinephrine, which can stop the vasodilation that occurs during a severe allergic reaction, thereby saving the patient. Though the sequence of events that occurs during an allergic reaction is generally well understood by scientists and physicians, we have not developed an actual cure for allergies or asthma. Though there are a number of effective interventions that prevent or reduce the symptoms associated with allergies, treating the underlying cause for allergies has eluded scientists. Nonetheless, several promising lines of research provide hope that we can more effectively treat allergies in the future and possibly even cure them.
In recent years, immunotherapies have been touted as promising strategies for interventions in medications related to allergies. Immunotherapy leverages what we have learned about why allergies occur to try to prevent or minimize allergic reactions and the associated symptoms. Specifically, because allergic reactions are the immune system’s overreaction to an otherwise innocuous agent, immunotherapy aims to train the immune system to recognize that the substances the immune system is reacting to are not in fact harmful. Immunotherapy involves exposing a patient to small amounts of the allergen that causes an allergic reaction, so that the immune system has a chance to recognize that agent but at low doses that will not motivate the immune system to initiate an enormous reaction. With continuous and frequent exposure, the hope is that eventually the immune system will learn that the substance is not harmful and will therefore no longer react and cause the symptoms associated with allergies.
In the past, immunotherapy has taken often come in the form of shots, which requires that patients make frequent visits to the doctor’s office, usually weekly. Though this type of immunotherapy has proven effective, many people struggle to maintain the schedule of weekly doctor’s visits due to the inconvenience, while others do not like the invasive nature of shots. The Federal Drug Administration (FDA) has recently approved a new form of immunotherapy, which is a pill that dissolves in the mouth. The pill is approved for allergies to grasses and ragweed, and scientists are hopeful that they will soon have pills that can address all allergens. The next available pill will likely be one that combats allergies to dust mites.
Probiotics refer to microbes that promote the growth and survival of “good bacteria” and have been identified as a possible solution to allergies. Some researchers have suggested that a paucity of good bacteria in the stomach may enable the immune system to overreact to certain allergens in the environment. These scientists claim that living in extremely clean environments can reduce the amount of these important bacteria and actually make us more susceptible to allergies. A recent study conducted at Vanderbilt University demonstrated that those with allergies who took probiotics showed better health outcomes than did those who were given a placebo that involved no probiotics. Another study showed that kids with peanut allergies were able to overcome their peanut allergies with a treatment regimen that included probiotics. In this study, the probiotic treatment was done in conjunction with immunotherapy, so while the patients were subjected to probiotics, they were also exposed to increasing amounts of peanuts. It is therefore difficult to say whether the probiotics specifically impacted the immune system’s response to peanuts in this patient population. Another reason to question the impact of probiotics is that studies have also shown that administration of probiotics failed to improve symptoms associated with hay fever. Experts suggest that more research is required to understand the precise impact of bacteria and probiotics on the immune system and allergic reactions, but probiotics may offer a new intervention for dealing with allergies.
Ongoing scientific research that clarifies the mechanisms involved in allergic reactions will likely lead to more effective therapeutics and potentially allergy preventions. Some scientists have expressed hope that vaccines for certain allergies will one day be available, but the development of vaccines would depend on furthering our understanding of the complexity of allergic reactions, as well as the differences between different allergy types. In April of this year, researchers published an article in the academic journal Nature Communications that pointed to the role of a specific protein, Mbd2 in allergic reactions. Mbd2 appears to impact inflammation and to initiate epigenetic influences by affecting gene expression. This discovery may eventually shed light on new ways to treat allergies and asthma.
As allergies are on the rise, many clinicians and researchers believe that changing elements in our environment are increasing the prevalence of allergies. Thus, though our therapies and interventions for allergies may be improving over time, this progress is not necessarily reflected in the allergy status of human populations. With allergies on the rise, it is more critical than ever that we determine the specific causes and sequence of events that lead to allergic symptoms, particularly those that are life threatening so that we can develop ways to combat these reactions. Treatments like immunotherapies, which aim to minimize the reaction itself rather than to minimize symptoms associated with the response, will likely be those that are most likely to lead to full cures or preventions for allergies.
Anaphylaxis is an extremely severe allergic reaction, where the immune system releases histamine, basophils, mast cells, and other substances. The excessive reaction of the immune system to an allergen causes tightening of airways and difficulty breathing. Anaphylaxis can be fatal if not properly treated. Once it is clear that a patient is experiencing anaphylaxis, epinephrine is generally administered. People with extreme allergies often carry EpiPens, which facilitate a simple injection of epinephrine. EpiPens often save lives because there is a limited amount of time from the onset of anaphylaxis and death. For those who cannot get to the emergency room fast enough, an EpiPen makes all the difference.
While difficulty breathing and swallowing, as well as chest tightness are common and recognizable signs of anaphylaxis, there are several other symptoms that can indicate an anaphylactic reaction. These include: cough, diarrhea, anxiety, skin redness, slurred speech, swelling of the face, wheezing, unconsciousness, nausea, vomiting, hives, nasal congestion, and abdominal pain.
Some drugs can cause symptoms that are similar to those experienced during anaphylaxis. These drugs include aspirin, morphine, and x-ray dye. When people suffer anaphylactic-like symptoms in response to these drugs, they are not enduring an immune reaction like that which occurs in response to an allergen.
There are two main features of anaphylaxis: one is respiratory difficulty, which can occur as a result of asthma or laryngeal swelling, and the other is hypotension, which can present as loss of consciousness, collapse, or fainting. Anaphylaxis occurring without hypotension generally indicates the immediate use of epinephrine intramuscularly. However, epinephrine that occurs with hypotension is better treated with intravenously.
Anaphylaxis is usually diagnosed based on observation of clinical features consistent with the symptoms described above. However, there are also two biomarkers that can be tested for in the laboratory: histamine level and tryptase level. However, these tests cannot be performed rapidly and are not always available. Further, tests for histamine and typtase levels are not specific to anaphylaxis, as these levels can rise due to other conditions as well. Thus, it is most often the case that physicians and patients recognize the onset of anaphylaxis without biological tests.
Epinephrine, also known as adrenaline, helps reverse anaphylaxis by stimulating different adrenoreceptors. For instance, epinephrine stimulates a adrenoreceptors and thereby increases the resistance of peripheral vasculature. When the resistance of this vasculature increases, blood pressure improves and swelling reduces. When epinephrine stimulates b2 adrenoreceptors, bronchodilation occurs and swelling is further reduced.
Beta blockers reduce the effects of adrenaline and can therefore make anaphylaxis worse. They can also limit the ability of epinephrine to reverse an anaphylactic reaction. Other limitations in the treatment of anaphylaxis unfortunately derive from improper administration of epinephrine. Often epinephrine is not administered fast to enough to have maximal benefit, which can result from lack of availability of epinephrine (often due to never filling a prescription or not physically carrying an EpiPen) or lack of recognition of anaphylactic symptoms. Patients also frequently report being too scared to self-administer epinephrine with an EpiPen.
Knowing when and how to use the EpiPen for safe and precise delivery of epinephrine is critical during an anaphylactic reaction. There has been significant criticism of health care providers’ care of patients who are at risk for anaphylaxis. Of particular concern is that medical professionals tend not to properly train patients on how to use an EpiPen should they need one. Additionally, medical professionals and patients alike tend not to know the details of the dosing of epinephrine, which is also critical to the successful and safe reversal of anaphylaxis. Propoer training in this respect could significantly enhance the proper use of EpiPens, thereby saving more lives.
Though it can be critical to use epinephrine in response to anaphylaxis, doses that are too small or too large can themselves be life threatening. When epinephrine is administered intramuscularly, as it is with EpiPens, the proper dose for adults is 0.3 to 0.5 mL for a 1:1000 solution. Overdose is particularly risky when epinephrine is given intravenously. Those who are most vulnerable to the adverse overdose effects of epinephrine are the elderly and those with cardiovascular disease or hypertension. Nonetheless, the benefits of using epinephrine in the face of anaphylaxis appear to far outweigh the risks of not using it, even at higher risk patients.
Women suffer anaphylaxis more frequently than do men. People who suffer anaphylaxis from exposure to certain antigens are certainly at risk for future anaphylactic reactions, but the severity of their reactions is not predictive of the severity of future reactions. One reason for this is that the dose of allergen can impact the severity of reaction, and knowing the dose to which one was exposed can be difficult. In the long-term, however, the frequency and severity of anaphylactic episodes has been reported to decrease. Nevertheless, as anaphylaxis is a severe, potentially fatal condition that cannot always be reversed, it is important that patients acquire information on their allergies, understand their risks for developing anaphylaxis, and avoid allergens that could contribute to such a reaction.
For millions of people allergic to eggs, exposure to these agents can lead to severe and dangerous reactions. Children are much more likely than adults to suffer from egg allergies, and eggs are the second most common food that causes allergy in children, behind cow’s milk. In the United States, 1.5-3.2 percent of children are allergic to eggs, many of which are also allergic to milk. About half of those children diagnosed with egg allergy will outgrow the allergy by the age of 17. The American Academy of Allergy, Asthma, and Immunology has reported that of those children who do outgrow their egg allergy, approximately 45% outgrow it by the age of 5. The highest levels of antibodies against egg proteins were observed in these children around the age of 1.
Egg allergies occur when the immune system overreacts to substances contained in the white or the yolk of eggs. More often than not, egg allergies are a result of antibodies in the immune system that react to one of the proteins found in the egg white. These proteins are: ovomucoid, ovalbumin, ovotransferring, and lysosome. Of these proteins, ovomucoid is the one most likely to lead to an allergic reaction. Because egg whites cause the release of histamines, which are part of the immune system, non-allergic reactions can also occur in response to egg white exposure in what is referred to as egg white intolerance. In these cases, the immune reaction usually stays localized in the gastrointestinal tract. However, it can escalate to the point of anaphylaxis so, like egg allergies, must be taken seriously.
The egg yolk can also cause allergic reactions and tends to do so more often in adults than in children. The proteins in the egg yolk that can be problematic are: livetin, apovitillin, and phosvitin. For those who are allergic to a protein in egg whites can usually safely consume egg yolks, and those allergic to a protein in egg yolks can likely eat egg whites without difficulties. People with egg allergies can also usually tolerate egg substitutes.
Egg allergy diagnosis is usually made with skin prick testing or blood testing. Skin tests allow for the visual observation of inflammation in response to egg exposure, whereas blood tests can reveal the levels of relevant antibodies in the patient’s system in response to the food. There is no cure for egg allergies. Avoiding egg consumption is the most effective way to avoid allergic reactions, but accidental consumption does occur. If patients start feeling symptoms of anaphylaxis, such as a tightening throat, enlarged tongue, or difficulty breathing, epinephrine can be administered to reverse the dangerous reaction. It is therefore important that those with severe allergies to eggs carry an EpiPen.
Exposing young children to eggs can help protect them against an egg allergy. Specifically, giving infants cooked eggs around 4 to 6 months of age can potentially help safely introduce eggs and the associated proteins to the child’s immune system in a manner that will allow the immune system to subsequently recognize eggs and their proteins as innocuous.
A number of vaccines contain egg products and can cause reactions in those with egg allergies. In severe cases where patients cannot receive vaccines due to the egg products contained, physicians will likely recommend that all family members are vaccinated for the relevant condition to reduce the chances that the patient with suffer as a consequence of their lack of vaccination.
In addition to the dangerous results of egg exposure for those allergic to egg, other aversive reactions can also occur, such as urticaria and eczema, which are skin reactions that include rashes and hives and can itch and cause pain. A runny nose, sneezing, coughing, wheezing, and itchy, watery eyes can also result from egg allergy reactions.
These days, we hear a lot about kids developing allergies at a higher rate than in previous generations. Often, these allergies are quite serious. A common example is the peanut allergy that can be fatal if it leads to anaphylaxis, and the patient is not treated quickly enough. Given the growing number of allergies and associated anaphylaxis, many parents worry about how they can protect their children from these serious conditions.
First, it is never too early to test children for allergies. There is no minimum age for which testing is required. However, it is important to understand that allergies will not develop until people have been exposed to the allergens. In other words, children do not become allergic to pollen until they have been around pollen for a few springs. Similarly, they do not become allergic to peanuts until they have ingested peanut products. Testing too early may therefore lead parents to falsely believe that their children are protected from allergies, when they may simply not have had a chance to develop allergies yet. Indeed, many allergies do not present until adulthood, after significant exposure to an allergen has occurred over decades.
Testing your kids for allergies is therefore something you will want to do when true symptoms of allergy occur, even if they have tested negative in the past.
Another possibility to recognize is that “allergy-like” reactions can be indicative of other issues. For instance, rashes can occur for a number of reasons and do not necessarily signal an allergy to a product that was used in the area of the rash. At the same time, intolerance to certain substances can appear allergy-like while not posing the same risks as allergies. Glucose intolerant patients are not allergic to milk. Both food allergies and intolerance result in diarrhea and vomiting, but these symptoms are caused by different factors. Whereas allergies cause these symptoms because of an immune reaction, intolerance causes these symptoms because of deficiencies in enzymes that normally digest or absorb foods. Food allergies will often include key symptoms not conferred by intolerance that can help the child and parent identify the allergy. For example, swelling, hives, or difficulty breathing can occur with allergies but should not occur with intolerance.
There are a number of ways to test for allergies. Blood tests, skin tests, and diet tests are the most common. Blood tests are very quick, but because they involve a needle, kids often become upset at the prospect of this type of test. Similarly, intradermal skin tests involve injecting allergens into the skin with a needle.
Though in some circumstances, the allergist may determine that the blood test or intradermal skin test is most appropriate, percutaneous skin tests can provide highly accurate results and are less invasive. They are therefore often used for allergy diagnosis.
The percutaneous skin test exposes the top layer of skin to the allergens being tested. This exposure involves a quick scratch or prick that is minimally invasive. To prepare for this type of test, all antihistamines must be stopped a week before the test, so that the immune system goes back to its “natural” state, and its normal reaction to the allergens can be observed in testing. After the skin test is initiated, there is a waiting period of up to about 15 minutes, which gives the immune system time to react. At that point, the doctor can look at the skin and determine whether a reaction has occurred. Often, the doctor will test the reaction to a number of allergens at once, including a control, which is a substance that should cause no reaction in any patient.
Because the skin has been pricked or scratched, it may appear a bit redder or more inflamed than other parts of the body. The control therefore allows the doctor to see what “no reaction” should look like. The doctor can then compare the skin that received the control to the skin that received each allergen to determine which allergens the patient is allergic to, and also, to what extent the patient may be allergic to specific allergens. For instance, pollen may cause skin to become a bit more inflamed than the control, whereas mouse dander may result in highly inflamed skin. In this case, the doctor would know that the patient may be slightly allergic to pollen but that exposure to mice will cause much more severe symptoms for the patient.
Diet allergy tests, often called “elimination diets” test for allergies by individually removing certain foods from the diet and then monitoring allergy symptoms. These tests are often used when food allergies such as allergy to milk, nuts, eggs, wheat, or soy is suspected. If eliminating one of these foods also eliminates symptoms, the doctor may deem your child allergic to that food. However, a limitation of elimination diets is that they can also eliminate symptoms associated with other issues, such as a food intolerance and so may not necessarily pinpoint an allergy. Misdiagnosis of allergies, particularly of food allergies, is also on the rise lately and is of concern because the avoidance of certain food groups is implicated in malnutrition. It is generally agreed that unless there is a significant medical concern associated with ingestion of important food groups, these groups should not be avoided.
If your child tests positive for an allergy, the specific treatment will depend on a number of factors, including the specific allergen, the symptoms associated with the allergy, and how severe the allergy appears to be. Often, allergies can be managed with regular allergy shots or oral medications. If the allergy is serious enough, you and your child may need to learn to use an Epi Pen and to create a plan that enables your child to always have access to one. An Epi Pen is used in the case of anaphylaxis that occurs outside a medical facility. By pushing the Epi Pen into the skin of the patient (often in the thigh), the Epi Pen injects the chemical epinephrine into the blood stream, which constricts blood vessels and opens up the airways in the lungs. By its actions, epinephrine reverses typical symptoms of allergic reactions, including wheezing, low blood pressure, hives, itchy skin, and most importantly, breathing difficulties. Its impact on the latter is a lifesaver in many scenarios.
A growing number of latex allergies are being recognized and diagnosed. It is believed that about 3 million people in the United States are allergic to latex. Those allergic to latex react to a milky fluid found in latex that is produced by rubber trees. As with other allergies, the immune system perceives the allergen (i.e. the milky fluid found in latex) as harmful. Many latex allergies are mild and may simply cause some slight irritation to the skin, termed irritant dermatitis. However, the allergy can also be much more serious, leading to hives, asthma, rhino-conjunctivitis, and of particularly concern, anaphylaxis. Because anaphylaxis is potentially fatal, increasing our understanding of latex allergy and how it may lead to this serious condition is important. Further, it is critical that people recognize risk factors for latex allergy so that they can minimize the likelihood of developing this allergy and manage the allergy safely when it does occur.
Like many other allergies, the risk for developing a latex allergy increases with exposure to latex. Between 7 and 10% of workers who where latex gloves regularly become allergic to latex. For instance, one study determined that over 12% of all anesthesiologists suffer from latex allergy, and many studies have reported the relatively high numbers of nurses with latex allergy. Though latex free gloves tend to be more expensive than latex gloves, several hospital programs have been developed to implement latex-free only gloves for use within the hospital. Supporters of these initiatives argue that the liability and spending that is saved by preventing employees from developing bothersome and potentially dangerous allergies is worth the added financial cost. A Japanese analysis, for example, concluded that using latex-free gloves could actually end up saving 3.5 million yen each year.
The FDA, however, says that latex free labels are misleading because there is no test that can accurately and definitively assure that no latex is present in products. However, they also acknowledge that complete elimination of latex is probably not required to prevent allergic reactions to latex. Accordingly, programs that switch to “latex free” gloves have
indeed significantly reduced latex allergies among healthcare workers.
Those with a family history of allergy seem to be more likely to suffer from latex allergies. About 33% of all people who receive positive skin test results for latex allergy do not demonstrate any allergy symptoms. For those who do suffer from allergic symptoms when exposed to latex, using powder free latex gloves can reduce symptoms, particularly if those symptoms are respiratory because reducing powder minimizes the airborne exposure to latex.
Those allergic to fruits and vegetables may be more prone to latex allergies. Recently, some researchers have begun to focus on the potential cross-reactivity between latex allergies and food allergies. Indeed, a number of people who are allergic to latex turn out to also be allergic to specific foods Some of the most highly implicated foods for those allergic to latex are avocado, potato, and banana. Tomato, chestnut, bell peppers, papaya, and kiwi are also often problematic for those with allergies to latex. Some clinicians use the term “latex-fruit syndrome” because of the relatively high incidence of comorbid allergy to both latex and fruit. The reason this cross-reactivity occurs is that the protein in latex that leads to an allergic reaction is structurally similar to proteins found in many foods, particularly fruits and vegetables.
The elderly population also appears to be vulnerable to latex allergy, though whether this vulnerability is simply due to an increased likelihood that elderly individuals have been exposed to latex more than younger individuals is not clear. Another group that often suffers from latex allergies is children with spina bifida. Between one quarter and two thirds of children with spina bifida test positive for latex allergy. Many studies conducted in Northern America, Europe, and Asia find about half of those with spina bifida also suffer from latex allergy.
Much of the literature focuses on latex in gloves, which has been shown to significantly impact the healthcare community. However, latex has been identified in a number of products, ranging from balloons to yoga mats to eyelash glue. There have also been reports of vaccines and flu shots causing latex allergy reactions. Though many people misinterpreted these observations as indicating a problem with the medicine that was injected into patients, it is generally agreed that the most likely cause for these reactions is the latex found in syringes. Further support for this notion comes from the fact that the reactions tended to be local, causing irritation in the area of the skin where the injection was made. If, on the other hand, the medicine itself contained latex, a more widespread reaction would be expected with the injection of that medicine into a patient’s circulation.
Restaurants are another place where people report latex allergies. Because workers often wear latex gloves while handling food in restaurants, those who later consume that food can react to the latex that remains on the food. As a result, many restaurants have switched to vinyl gloves, though it has been reported that vinyl suffers its own dangers. In 1999, Rhode Island became the first restaurant to ban the use of latex gloves in restaurants. In the next few years, both Arizona and Oregon followed.
Latex allergies can be identified with both serum testing and skin prick testing. The American Latex Allergy Association says that the early symptoms of latex allergy include: hives, welts, a runny nose, swelling, headache, sneezing, itching, watery or reddening eyes, sore throat, chest tightness, wheezing, shortness of breath, or abdominal cramps.
There is not yet a universally adopted highly effective treatment for latex. The best option for preventing latex allergy is currently avoidance. However, other treatments have been shown to be useful in certain cases. For instance, last year, researchers successfully desensitized a nurse to latex using sublingual immunotherapy, which involves placing a small amount of latex under the tongue. This type of therapy works by getting the immune system used to the allergen in small doses so that it no longer reacts to the allergen as if it is a dangerous foreign invader.