Allergies Explained
What are allergies?
We have heard of allergies and many of us experience them, but what are they exactly? Knowing how our bodies respond to our environments and what happens when things go wrong helps us understand how best to pursue treatment.
Allergies are a type of hypersensitivity reaction. In the case of allergies, our immune system is responding to a foreign substance as if it were a life-threatening assault. Common triggers (know as allergens) include various pollens, dust, animal dander, mold, fragrances, and foods. These substances on their own are not toxic, but our body reacts as if they were. This reaction causes real damage to our tissues and in their strongest form can cause anaphylaxis a life-threatening situation. Allergies are more than itchy eyes and runny noses!
Allergy symptoms are more often experienced in the skin, respiratory tract (nose, throat, lungs), and the gastrointestinal tract. This is because cells that produce and release histamine and other inflammatory chemicals are densely packed in these tissues (1). Anyone with allergies is familiar with the effects of histamine: redness, swelling, itching, and loss of fluids (watery eyes, nose). Common over the counter allergy medications focus on blocking histamine from binding to cells and causing this reaction. Medications like Sudafed are also commonly used to dry up tissues leading people to try balancing between allergy symptoms and overly dry eyes and respiratory tracts.
Histamine
One of the big problems with allergy medications is the fact that they only block one of the many different histamine receptors in the body - H1 (2). H1 receptors not only create our familiar allergy symptoms, they also regulate our internal clocks - making us more awake, and they can trigger motion sickness. This is why taking allergy medications can make us drowsy, and is the mechanism behind the anti-nausea medication Dramamine. A popular anti-anxiety medication Hydroxyzine also works by blocking H1 receptors and diminishing the stimulating effects of histamine.
H2 receptors are found in cells lining the stomach. These cells, called parietal cells, are responsible for creating the stomach acid we need to break our food down and prepare it for absorption. This is a common target for the treatment of acid reflux which we should all know is usually caused by too little stomach acid, poor muscle tone, and poor diets. Suppressing stomach acid over long periods of time is linked to a plethora of diseases later such as osteoporosis, pneumonia, Clostridium difficil colitis, vitamin B12 deficiency, stomach cancer, and dementia. H2 receptors are also found in the heart, the uterus, and lining our blood vessels. Here they encourage muscle relaxation. I have encountered patients with painful periods who received benefit after stopping their allergy medications.
H3 receptors are found in our nervous system especially our brain and spinal cord. They actually act as a break for histamine production. The more histamine binds to H3 receptors, the less your body will produce.
H4 receptors were discovered in 2001, and they play a role in regulating how many white blood cells are released from our bone marrow and influence our mast cells which produce histamine.
As you can see, there is a lot going on when we consider allergies!
Allergy testing
Now that we have a better understanding of what allergies are and the role histamine plays, how do you figure out what you are allergic to? There are a few different routes to go here. Traditionally, a skin scratch test is used in an allergist’s office. Here samples of different allergens are scratched into the skin and distilled water is used as a control. Your skin’s response to these allergens is measured and recorded. The substances that cause inflammation are recorded as your allergens.
Another route is to measure your body’s reaction to antigens in your blood. When your body is exposed to an allergen, you will make a specific type of antibody known as IgE - this is what will bind to mast cells and trigger the release of histamine. A blood sample can be collected and then your blood will be examined for reactions to common allergens.
When considering food allergies - we need to get a bit more specific. As mentioned above, allergies are a type of hypersensitivity reaction. The defining characteristics involve the production of IgE antibodies and histamine release. True food allergies such as peanuts and shellfish can create anaphylaxis just like a bee sting. When someone has a true food allergy (or bee sting allergy) they are encouraged to carry an epi-pen (a specially constructed syringe filled with epinephrine to counter the runaway affects of histamine in these cases). What many people call food allergies are actually a different class of hypersensitivity and as such are not true allergies. Here we have different antibody responses, or responses that don’t involve antibodies at all.
A common test for food hypersensitivities involves a blood draw where IgG and IgA antibodies are tested. This can give a good idea of foods that are doing you harm when you eat them. However, because there are multiple ways the body can mount a hypersensitivity response, these tests cannot give you all the information you need. Another broader test is an elimination and rechallenge diet. These take on many forms and should be personalized for you specifically. Person’s with eating disorders should be very cautious about elimination diets and work with a medical professional well versed in helping those with eating disorders navigate an evaluation for food hypersensitivities.
Allergy treatment
Now you know why your allergies feel the way they do and what your allergens are, what do you do next? There are six general categories of treatment to consider, combine, and implement (3):
Avoid your allergens - this is much easier with foods than with environmental allergens. You can choose not to have pets if animal dander is your allergen, you can move to a different environment, you can have mold remediation done on your home, and you can practice pristine household and personal cleanliness - all of these things will help, but sometimes they aren’t feasible, and sometimes they aren’t quite enough.
Desensitization therapy - this has historically taken the form of allergy shots. The effect is often temporary and it involves shots at least 3x weekly at your allergist’s office. Newer forms of desensitization therapy are being developed with SLIT (Sublingual immunotherapy) being very promising. Here, small amounts of your allergen are given orally for you to hold under your tongue. As our immune systems develop through our digestive system, this treatment has been quite successful. There are FDA approved SLIT therapy treatments for pollens of mixed grasses, ragweed, peanuts, and dust mites. Additional SLIT treatments are available which haven’t been FDA approved but have resulted in great benefit. At Herbs & Hands, I work with homeopathically diluted mixtures of allergens to common local inhalants to help my patients with desensitization therapy. Another treatment that produces mixed results is a spoonful of raw local honey daily to introduce small amounts of your local pollen orally. Some with asthma have experienced increases in their symptoms with this treatment, so be sure to work with a medical provider to come up with a plan should this be the case for you.
Blocking IgE - there is one treatment for this currently and it is only for extreme allergies as it is a form of invasive immunotherapy. The drug is in the same class as the biologic drugs used for treating autoimmune disorders - another form of hypersensitivity this time to one’s own tissues.
Inhibiting mast cells from releasing histamine - mast cell stabilizers. The only pharmaceutical drug used for this is cromolyn. Nutritionally, a diet rich in bioflavonoids like quercitin which is found in onions, garlic, apples, and other foods can stabilize our mast cells. Vitamin C also plays a role here too. Eating your 7-10 servings of vegetables and fruits daily will help your allergy symptoms as well as your overall health. I will never stop beating that drum!
Block histamine and it’s effects. Here is where “allergy medicines” like Benedryl, Allegra, Zyrtec and their kin come in. Another great treatment for this is the ingestion of nettles. Freeze dried forms are best. You will need to take nettles several times a day, but they work effectively when you find a high quality source.
Reduce overall inflammation. Hypersensitivity reactions are the result of an immune system out of balance. Reducing overall inflammation plays a major roll in reducing these responses and the severity of their symptoms. We must remember that hypersensitivity responses cause actual tissue damage which accumulates over time. To reduce inflammation, focus on a healthy diet, good sleep hygiene, regular exercise, stress management, and targeted nutritional therapies. We cannot simply throw turmeric at our inflammation, our bodies need to have all the nutrients required to use anti-inflammatory herbs. When in doubt, start with your diet.
Next steps
If what you have read here inspires you to look at your allergy treatment differently, congratulations! If you are local to Troutdale, Oregon and would like to work with me, you can schedule a visit here. If you are in Oregon and would like to work with me, you can schedule a telemedicine visit here. If you are not in the area, look for a Naturopathic Physician near you. You can search for one through your State’s association of Naturopathic Physicians or through your national association. Here in Oregon, we have the OANP, and for the United States, we have the AANP.
To our health!
References:
Marieb, E, Hoehn, K, Human Anatomy & Physiology: 9th Edition, 2013, Pearson Publishing
University of Bristol, “Histamine Receptors”, wwwchm.bris.ac.uk/motm/histamine/jm/receptors.html accessed 5/11/2020
Delves, P, et.al, Roitt’s Essential Immunology: 13th Edition, 2017, John Wiley & Sons Inc
