Shortly after a long run up a dry dirt trail in our beautiful Santa Monica Mountains last weekend, I started sneezing repeatedly. The sneezing didn’t subside for a good 24 hours! Little wonder that I have decided to sit down and write about…allergies. Who gets allergies? Although 20% of us display allergy symptoms, about 55% of us actually would test positive for at least one allergen. Allergies are inherited - if one parent is allergic, their offspring have a 50% chance of having allergies, and that risk grows to 75% if both parents have allergies. Allergies can develop at any age; something that has never posed a problem may suddenly cause a reaction.
Allergies are an abnormal response of the immune system - in other words, our body reacts to a usually harmless substance, or allergen, in the environment. Common allergens include pollen, mold, dust mites, pet dander, peanuts, and seafood, various perfumes and dyes, medications, latex, metals such as nickel, and chemicals in household cleaning products. Symptoms tend to be seasonal, since major allergens, such as pollen, appear in the spring, and mold levels rise in the fall. We are exposed to allergens by inhaling them, swallowing them, or from skin contact.
Once exposure to an allergen occurs, it triggers a series of events known as the allergic reaction. The body produces IgE, an antibody that binds to the allergen. It then attaches to a mast cell, which is a type of blood cell that regulates the immune system. Mast cells are found in our airways, intestines, and every tissue. Histamine is then released, which causes most of the troublesome symptoms.
Allergy symptoms vary.
- Allergic rhinitis symptoms include itchy, watery eyes, sneezing, runny nose, sore throat, blocked nasal passages, post nasal drip, loss of taste, loss of voice, and fatigue.
- Allergic dermatitis occurs when there is direct skin contact with an allergen. This skin reaction, which may include eczema and other types of rashes, may take 24 to 48 hours to develop. Common allergens include latex, perfumes, hair dyes, antibiotic creams, nickel, and adhesives.
- Food allergies are most often caused by peanuts and other tree nuts, eggs, milk, wheat, and shellfish. These result in tingling or itching in the mouth, hives, itching or eczema, swelling of the lips, face, tongue and throat or other parts of the body, wheezing, nasal congestion or trouble breathing, abdominal pain, diarrhea, nausea or vomiting, dizziness, lightheadedness or fainting, and even anaphylaxis.
- A sting from a bee or other insect can cause local swelling, redness, and pain. Reactions vary from mild to severe.
Anaphylaxis, the most severe allergic reaction, is a whole body reaction that may include hives, itching, wheezing, shortness of breath, and tingling in the hands, feet, lips and scalp. Anaphylaxis is life threatening and requires immediate medical attention. Symptoms can progress very quickly, leading to difficulty breathing; so time is of the essence.
An allergy diagnosis is based upon a physical examination and history. Sometimes specific triggers are obvious, such as a new pet in the home, or a new laundry detergent. For more difficult cases, an allergist can perform skin tests to identify the specific allergens.
How do we treat allergies? First, try to avoid the allergen. This is easier if it is, say, a plant in the yard, than if it is a beloved pet! When avoidance isn’t possible, medication can usually control the symptoms. Work with your doctor – you may need to try a variety before settling on the best medication and dose. For common mild symptoms, antihistamines like Claritin, Allegra, or Zyrtec, or decongestants like Sudafed are used. If these are not effective, nasal allergy symptoms can also be treated with steroid, antihistamine, or saline nasal sprays. Skin allergy rashes are usually easily treated with hydrocortisone creams. Those who are prone to severe allergy symptoms like anaphylaxis should always carry an epinephrine auto-injector pen. If symptoms are chronic, or difficult to control, see your doctor or an allergist for further evaluation, allergy testing, and possibly a series of allergy immunotherapy shots.
How do we tell the difference between a cold and an allergy? Colds are caused by one of hundreds of different viruses, and allergies are caused by an overactive immune system to an allergen. Viruses are contagious and allergies are not. Both can occur any time of the year, although colds show up more frequently in the winter, and allergies in the spring and fall. Both can result in a cough, fatigue, sore throat, and runny nose. Allergies never cause body aches or fevers, and colds may. The onset of symptoms of a cold takes two to three days from exposure, where allergy symptoms can show up immediately. The biggest difference, of course, is that colds last from three to 14 days. Allergies can last for days, months, or even years.
Dr. Alan Frischer is former chief of staff and former chief of medicine at Downey Regional Medical Center. Write to him in care of this newspaper at 8301 E. Florence Ave., Suite 100, Downey, CA 90240.
Published: April 23, 2015 - Volume 14 - Issue 02