allergies: What You Need To Know
Allergies are reactions caused by a hypersensitivity of the immune system to a substance ingested or in the environment (an “allergen”). These substances may cause little or no effect in most people, but a percentage of the population may experience significant symptoms that can affect quality of life, or even threaten life itself.
A SHORT HISTORY OF ALLERGIES
If you told a doctor a little more than a hundred years ago that you had an allergy, he/she wouldn’t recognize the word. “Allergy” was coined in 1906 by an Austrian pediatrician and immunologist named Clemens Von Pirquet. The word is derived from the Greek allos meaning “other” and ergon meaning “reaction”.
Von Pirquet and his associates noted that certain people who received a variety of smallpox vaccine had more severe reactions than most. Another scientist, Charles Mantoux, used this knowledge to develop a test for tuberculosis where an allergic skin reaction to a substance isolated from the microbe revealed previous exposure. A form of this test is still used today.
The worst allergic reaction, known as anaphylactic shock, was discovered by a french physiologist Charles Richet, who with his partner Dr. Paul Portier, injected the venom of a sea anemone into a number of dogs. Hoping to find some substance that would protect humans (called prophylaxis) from jellyfish stings, they instead found that a second injection killed many of the dogs. Since this was the opposite of protection, they termed it anaphylaxis.
HOW ALLERGENS CAUSE REACTIONS
Common allergens to which people are exposed include pollens, metals, insect stings, medications, and certain foods. There are also internal factors such as age, sex, race, and family history. How do these all combine to cause the physical symptoms of an allergy?
Put simply, an immune reaction against an allergen occurs when it’s encountered for the first time; let’s say it’s a bee sting. Cells in the body called “T-cells” identify the bee venom and interact with other cells called “B cells”. The B cells, in turn, produce certain antibodies called “IgE”. IgE attaches to the surface of cells called “basophils” and “mast cells”. These cells are now “sensitized” to the venom. No physical effects are usually noticed at the time by the victim beyond the sting itself.
When a second exposure to the allergen occurs, however, it’s a different story. The sensitized mast cells and basophils are activated and produce a large amount of histamine and other inflammatory chemicals. The flood of these into the system can cause possibly severe physical reactions.
SYMPTOMS OF ALLERGIES
Allergies may appear in various forms, from mild to life-threatening. These conditions include hay fever, food allergies, local skin reactions (called “atopic dermatitis”), drug/toxin reactions, and allergic asthma. Common symptoms include red eyes, itching, nasal congestion, difficulty breathing, and swelling. In the worst situations, a body-wide reaction called “anaphylaxis” causes rashes, major swelling, and difficulty breathing to the point of suffocation.
Hay Fever: Hay fever is a (usually) seasonal reaction to high pollen counts in the air from certain plants. People with hay fever won’t likely have a fever, but they will have sneezing from a runny, clogged nose, red, itchy, watery eyes and “postnasal drip”, a condition where a cough is caused when mucus runs down the throat from the back of the nose.
Different grasses, trees, and flowering plants will release pollens at different times of the year, and it is often difficult to identify what allergen is causing the symptoms. Skin “patch”, scratch, or blood tests may determine if a particular substance is causing the sensitivity.
Atopic Dermatitis: Most people who have atopic dermatitis have had allergies before or a family member with similar problems such as hay fever or asthma. Common allergens include animal dander, dust mites, exposure to certain foods, stress, and dry, cold weather.
The condition usually starts with itchy, dry skin.. Scratching causes inflammation, swelling, and redness, and may initiate an infection in the area. Small, oozy blisters sometimes occur that crust over with time. Although mild versions cover small areas and are improved with lotions, severe versions require more intense therapy.
Rashes may recur over the same area time and again, leading to toughened, thick skin that appears darker than other areas. These areas are usually on the scalp and cheeks of infants but may be seen on the baby’s knees or elbows. Other areas may be affected with age, such as the ankles, wrists, legs, the buttocks, and the nape of the neck.
Food Allergies: Four or five percent of the population is allergic to some kind of food. In children, eggs, milk and peanuts are often responsible; in adults, shellfish, nuts from trees (for example, walnuts), milk and eggs are common triggers to a reaction. It should be noted that an allergy to milk is different that intolerance caused by a deficiency of the enzyme needed to digest it (otherwise known as “lactose intolerance”.
Drug Allergies: A drug allergy is caused after repeated exposure to a medicine. Some of the most common include Penicillins, Sulfa Drugs, non-synthetic Insulins, seizure meds, and those containing iodine.
Drug allergies are often confused with what are called “adverse reactions”. An adverse reaction is a known ill effect that can occur with the use of a medication. For example, if a drug is known to cause nausea in some patients, that is considered an adverse reaction as opposed to an allergy.
Despite this, many will report an allergy to a particular drug to their healthcare provider. Some of the reasons that people will write “allergic” on their medical interview sheet include:
- The drug causes symptoms that makes them feel unwell.
- A family member has a history of an allergy to the drug, and they assume that the same goes for them.
- An incident in their childhood resembled an allergic reaction, so better safe than sorry.
- Negative comments online or elsewhere cause reluctance to take the medicine.
- Philosophically opposed to a particular type of drug (antibiotics, psychotropics).
- An actual allergy.
Note that a true allergy is placed last on this list; the World Allergy Association reports that less than 10% of reactions to medications are actually allergies caused by an immune response. Most symptoms that people get after taking medicine are, instead, adverse or “side” effects. It may not always be easy to tell the difference, but a true drug allergy will show immune-mediated symptoms such as hives, itchy skin or eyes, rashes, lip and tongue swelling, and wheezing. Blood pressure may drop precipitously in some cases.
Toxin Allergies: It’s common to have local redness, discomfort, itching and swelling when a toxin, such as bee venom, is introduced into the body. Your immune system, however, may respond strongly in the form of an allergy. Common insects involved are bees, wasps, hornets, and fire ants.
When the immune system gets involved, the reactions may be more severe, with hives, redness and swelling affecting large areas of skin. Swelling may extend to the tongue, throat, lips, and elsewhere. Stomach upset, nausea and vomiting, and diarrhea are common. The effects may take days to completely resolve.
DRUG TREATMENT OF ALLERGY SYMPTOMS
Allergies, when mild, are treated with medications that help relieve the specific symptoms.
Antihistamines in oral, intranasal and ophthalmic (eye drop) form are useful to deal with the sneezing, runny nose, and itchy eyes associated with hay fever. Nasal decongestants like oral pseudoephedrine (Sudafed) and the nasal spray oxymetazoline (Afrin, Dristan) are useful drugs to have in the medicine cabinet. It should be noted, however, that the nasal sprays are addictive when used for more than three days. That is, if you stop using them, your nose will become stuffy again.
Others like diphenhydramine (Benadryl) may help, but are prone to causing drowsiness in higher doses. Longer term therapy with intranasal steroids like Atrovent (ipratropium) or NasalCrom (cromolyn sodium) is another option. These drugs are best for long term therapy, however, as the effects are not felt immediately.
In the worst cases, epinephrine (also known as adrenaline) is necessary as an injectable to improve symptoms that affect the entire body. A future article will discuss this type of event in detail.
NATURAL TREATMENT OF ALLERGY SYMPTOMS
Many experience relief from allergies when they use an item known as a “Neti pot” to relieve congestion and pressure. The Neti pot essentially looks like a version of Alladin’s lamp, and allows the delivery of sterile solutions into the nasal cavity.
Neti pots work by thinning out mucus. The hairs in the nose, called “cilia” are aided in their attempts to eliminate mucus and allergens by the flushing action of the sterile saline solution delivered by the Neti Pot.
Some may have doubts about the effectiveness of the Neti Pot, but research backs up the benefits of nasal “irrigation” to relieve some allergy symptoms. Nasal irrigation via a Neti Pot may help decrease the need for drugs.
One concern related to Neti pots, however, is the importance of ensuring that you are using sterile solution when you irrigate. Non-sterile solutions, even tap water, may transmit infections directly into the body; two deaths in Louisiana were attributed to Neti pot use of contaminated water. Neti pots also must be washed after every use, as you would wash your dishes after every meal.
A natural remedy getting some serious attention lately is Butterbur. In a recent British Medical Joural study, butterbur extract (ZE 339) four times daily equaled the effects of a popular antihistamine–without causing drowsiness!
Goldenseal, Nettles, Resveratrol, Quercetin, and Vitamin C as well as saline spray may be helpful. Ragweed sufferers, however, should realize that some plants commonly used in herbal remedies, like Chamomile and Echinacea, might cross-react in hay fever sufferers to make symptoms worse.
You might be surprised to know that acupuncture has some evidence for effectiveness against certain allergies. acupuncture. Based on the idea that stimulating certain points on the body can cause effects inside, a study of 26 hay fever patients found in the American Journal of Chinese Medicine and described in WebMD appeared to improve symptoms in all without adverse effects. Another experiment eliminated allergic symptoms in half the patients studied.
Allergies can be nuisances or they can be life-threatening. In situations where we might spend a larger part of our day outdoors, as in survival, it’s important to know the signs, symptoms, and treatments when our immune systems go into overload.
Joe Alton MD
Joe Alton, MD
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