Allergies are the banal yet persistent stumbling block of everyday life, and there is some debate about whether allergies are genetic or not. While the presence of allergies in your body does not 100% guarantee genetic passing to any child you may have, there is overwhelming evidence that the vast majority of allergies have a genetic factor. Kathryn Edwards, M.D., an expert allergist from Robbinsville, NJ, has provided info about the causes of allergies and what role the genetic code plays in their development.
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What Causes Allergies?
Allergies are a misguided defense mechanism of our bodies. When exposed to an allergen, such as dust, medicines, certain foods, or plant matter like pollen or sap, the body senses the allergen as a threat to the immune system. The body releases chemicals like histamine to eject the substance out of the body, which then triggers reactions like a runny nose, swelling, itching, and breathing issues.
Proof that Allergies are Genetic
In many studies resulting in updated articles every year, allergies are partially genetic. Debate abounds over which allergies could be passed from parent to child and over the statistics on the likelihood that allergies, in general, can be hereditary. Gender can affect parent-to-child passing, and the environmental aspects of where a child is raised cannot be ignored. One support for the ‘genetic causes’ argument is the existence of atopic allergies such as asthma, eczema, and allergic hay fever.
Atopy is the hereditary disposition to develop intense immune reactions to common allergens. Environmental factors during developmental stages such as infancy and childhood can determine how heightened atopy can become in a person. A normal situation of atopic allergies forming is an infant born with food and skin allergies.
If the infant is raised in an inner-city, urbanized neighborhood, pollution in the air and perhaps pet hair or dander can give way to nasal issues like hay fever or asthma. The combination of genetic sensitivity and environmental factors just inflicted the child with three separate allergies, if not more. Genetics also links arms with gender, with some studies finding that increased risk of passing between parents and children of the same gender is far more likely. Mothers are more likely to pass allergies to only their daughters, while fathers are more likely to pass allergies only to their sons.
A Quick Look at the Types of Allergies
From food to flora, from the sinuses to the skin, allergies are categorized by the reaction’s location and the triggers. These can include:
- Airborne allergens (pollen, mold, dust mites, pet dander)
- Cutaneous irritants/allergens (metals, plants, latex, pet remnants like saliva or urine)
- Food allergens (dairy, eggs, nuts, fish and shellfish, wheat, soy
- Insect-related allergens (cockroaches in general, insect bites, insect stings)
- Chemicals (bleach, sanitizer, laundry or dish detergent, cleaners, polishes, sprays)
- Medicines (antibiotics, anti-inflammatory drugs, insulin, antiseizure drugs, muscle relaxers, specialized medications for HIV treatment or chemotherapy)
Cross-reaction allergies also exist and can throw off most patients that attempt to self-diagnose. This happens when one type of allergen is found in a non-corresponding source, like pollen from a certain plant passing down into the fruit and being mistaken for a food allergy.
Cross-reactions can result between organic and inorganic sources as well, like an interesting observation that latex-allergic patients are more likely allergic to bananas, kiwis, avocados, and chestnuts.
Is Prevention Possible?
Unfortunately, no magic pill or potion exists to prevent allergies from developing in someone’s body. As there is no way to know for certain if a genetic disposition will develop into a full-blown, lifelong allergy until a child has lived for several years, there is no prevention method.
Some studies, both finished and ongoing, use cutting-edge technology to see if certain genes could be present in an embryo. Genetic testing for very specific antibodies may help in determining whether a resulting infant could have allergies. If the genes can be found, isolated, and removed, this could assist exponentially with preventing allergies from passing from parent to offspring. Allergies are not entirely preventable, but treatments like medicines, injections, and even surgery make allergies manageable.
How Do Allergists Find Allergies?
An allergist/immunologist consults a patient by discussing medical history, then performs one or more tests to determine which allergies are present. Taking into account the patient’s medical background, current lifestyle, sometimes future plans, and frequented environments like home and work, an allergist or immunologist carefully develops a treatment plan.
Prick testing is the most common type of testing, done by infusing the allergen into some pure water, dropping it on a small patch of skin, then scratching the skin to allow the allergen to immerse. In a matter of minutes, an allergist can determine if the patient has an allergy. Sometimes the allergen water is injected into the top layer of skin and checked after a few days.
Blood testing involves finding how many allergy-specific antibodies are floating around in the bloodstream. This type of test is done when a patient is taking medication that could produce false negatives in the test results or cannot handle the needles or amount of scratching for prick testing. Severe skin irritation or risk of anaphylaxis would also call for a blood test, as would easily-triggered asthma or an unstable heart.
Reactions like allergic contact dermatitis are a delayed reaction, and patch testing is used to determine the trigger. A patch test includes the allergic substance taped to a section of skin on the back and the patient being advised to avoid water and return for an initial read after two days. Another one or two days after the patch is removed, the allergist can read the tested area and make a decisive diagnosis.
Pulmonary function testing, known better as spirometry, is performed for patients to see how well the lungs function. The allergist observes how much air the lungs can hold, how quickly the patient breathes, and how well the patient can filter out carbon dioxide and refill the lungs with fresh oxygen. A lung function test helps to find how much an allergen-triggered asthma attack has obstructed a patient’s breathing by treating the breathing tube with albuterol. Significant improvement will indicate asthma triggered by allergies, and records of this testing greatly assist in preventing future debilitating allergic reactions.
Avoidance and medication is the most common treatment for allergies. Over-the-counter medications for respiratory and contact dermatitis are easy to access and simple to ingest or to apply, like antihistamines or hydrocortisone ointment.
Allergy shots are another treatment, boasting the added benefit of not remembering to take, apply, or safeguard medication. A regimen is necessary as the shots build resistance to an allergen, with several injections over a few months. Food-triggered allergies are not treatable by injections.
An alternative to shots, allergy drops, or sublingual immunotherapy (SLIT) are perfect for children or other patients adverse to needles. These are not as strong as injections, but immunotherapy drops are perfect for anyone wanting a non-invasive method.
Sublingual immunotherapy functions like a vaccine by exposing the body to minuscule, controlled doses of the allergen to build immunity, and usually come in tablet form.
About Kathryn Edwards, MD
Dr. Kathryn Edwards wields extensive education and sixteen years of service to the military and military families as an allergy specialist, bringing her experience and expertise to the Penn Medicine Becker ENT & Allergy practice. The Penn Medicine Becker ENT & Allergy clinic is a premier facility with some of the nation’s finest experts specializing in everything ear, nose, and throat.
Patients from all over the country and worldwide come in to be treated at any one of several locations in New Jersey and Pennsylvania. Schedule an in-person or online appointment with Dr. Edwards at the Robbinsville, NJ location by calling 609-436-5740.