Here’s what you need to know about allergies, including the causes, symptoms, and treatments for allergies.
Allergies are an uncommonly common health condition.
An allergy occurs when the immune system comes in contact with an allergen—a foreign but typically harmless substance, like pollen—that triggers an immune reaction.
An allergen can be something one eat, inhale, touch the skin or body. It makes you sneeze, cough, break into hives or a rash or even hamper your breathing. In severe cases, an allergic reaction can block airways and lower blood pressure, which can be potentially life-threatening.
While there are several different kinds of allergies, the most typical ones are mediated by an antibody called immunoglobulin E, or IgE, explains Gary Soffer, MD, pediatric allergist with Yale Medicine. “Most common allergies are triggered by protein substances such as those found in pollen or foods,” adds Dr Soffer.
Allergic reactions in the lungs can lead to conditions like asthma.
Asthma Canada
Allergy symptoms tend to occur after your immune system grows sensitivity to a precise allergen, says Purvi Parikh, MD, an immunologist with Allergy & Asthma Network. “When the body comes into contact with these substances it triggers a response through IgE that activates allergy cells like mast cells and basophils which then cause the cascade of symptoms throughout the body,” she says.
Unfortunately, allergies are on the rise. Some specialists consider it may be due to the over-sanitization, which affects people having more limited exposure to germs, parasites, and other infections than previous generations. Known as the hygiene hypothesis, this may cause the immune system to go down a pathway where it’s more likely to overreact to otherwise innocuous substances.
While there is no simple remedy for allergies, there are some measures to prevent the reactions, treatments to help with the symptoms, and strategies to lessen their impact.
Most common allergies
There are many types of allergies, each with distinct causes, symptoms, and treatments.
Food allergies
Dr. Parikh explains that any kind of food can be an allergen. However, the most common food allergies are to eggs, peanuts, tree nuts, milk, wheat, dairy, soy, fish, and shellfish. Somebody with food allergies needs to check the constituents of food and avoid the particular ingredients that trigger an allergic reaction.
A doctor may advise carrying an epinephrine autoinjector (EpiPen) at all times. The drug epinephrine can assist in reversing the most serious allergic reaction, known as anaphylaxis.
Insect bites allergies
There are plenty of insects that can aggravate an allergic response. Dr. Parikh explains that some people have a venom allergy (bees, wasps, hornets), which can be life-threatening. “They must carry an EpiPen,” she notes.
Mosquitoes and fire ants also can also provoke allergic reactions, but these may be slight threatening. Treating these kinds of allergic reactions requires a combination of antihistamines, topical creams, and ice for swelling.
Drug allergies
You can be allergic to any drug, but ones administered with injection or IV have a higher possibility to trigger an allergic reaction. In general, symptoms of a drug allergic reaction can combine a rash with or without other symptoms such as nausea, vomiting, diarrhoea, and shortness of breath. Treatment includes stringent restraint of the medication and possible desensitization if the individual absolutely needs the drug.
Respiratory or environmental allergies
Respiratory allergies, also identified as hay fever or allergic rhinitis, are common reactions to airborne allergens like dust mites, pollen, and cat and dog dander. The symptoms can be itchy, watery eyes, nasal congestion, asthma (including coughing, wheezing, and shortness of breath) as well as skin rashes.
Treatments for these sorts of environmental allergies differ widely based on symptoms, but Dr. Parikh suggests anyone with this kind of allergy symptoms see a board-certified allergist. “Asthma management is different from sinusitis vs. conjunctivitis,” she points out.
Skin allergies
Skin allergies can be a rash, hives, eczema, and others that are triggered by food, chemical (an ingredient in a product), or environmental allergen, explains Dr. Parikh. Treatment is subject to the kind of rash, how severe it is, and the reason.
One way to comprehend is to know if you are allergic to a particular skin or hair care product and do a patch test. Nevertheless, it’s not always straightforward to figure out the cause of skin rashes or hives. You can get hives for no reason, known as chronic idiopathic urticaria, or in response to cold temperatures, pressure on the skin (known as skin writing), the sun (known as solar urticaria), or stress.
Severe Allergies
Anaphylaxis is the most critical manifestation of an allergy. It generally occurs with food allergies or stinging insect allergies Dr. Soffer reveals.
Symptoms can involve diffuse hives, swelling, difficulty breathing, vomiting, and a severe drop in blood pressure. “Patients in anaphylaxis can die from their allergy if not treated in an appropriate and timely manner,” he notes. Dr. Parikh adds that it can involve multiple organ systems.
Epinephrine (also known as adrenaline), can instantly neutralise swelling and other symptoms that occur during an anaphylactic reaction—emergency medical treatment is necessary.
Allergies’chronic implications
There are multiple health conditions linked to allergies, explains Dr. Parikh like:
- Oral allergy syndrome, which is a when people who are allergic to pollen have an itchy or tingling lips and throat when they eat certain fruits and veggies, due to a cross reaction
- Hives
- Allergic asthma
- Sinusitis
- Eosinophilic esophagitis, a chronic immune problem where white blood cells congregate and damage tissue in the esophagus, sometimes due to allergies, which can lead to difficulty swallowing.
- Allergy-related headaches/migraines
- Insomnia
- Eczema
- Allergic conjunctivitis, an inflammation of the eye’s lining
Allergy diagnosis
Allergic rhinitis (environmental allergies), food allergies, and reactions to stinging insect allergies are all originally assessed with a careful history.
“If that history is indicative of an allergic reaction then skin testing or blood testing is often performed,” says Dr. Soffer. Food allergy examination should never be done without a fair clinical history of a reaction, and only precise foods of concern should be evaluated, he says.
Allergy tests
There are a few different types of allergy tests, depending on the allergy in question.
Skin prick test
The skin prick test includes an allergist pricking the skin and putting a tiny amount of the possible allergen in the area so it can reach beneath the skin. If there is an allergy, a red, itchy bump will likely appear.
Oral challenge test
This kind of test is done less frequently because it requires an allergist administering little quantities of a food allergen via capsule or with an injection. You will then be strictly observed for a response. If you have one, you can be immediately treated, but if you do not, it can support definitively rule out a specific food allergy.
Blood test
In a blood test, you will be examined for IgE antibodies, the antibodies generated by the immune system when exposed to an allergy-causing substance. The presence of IgE antibodies implies that the body identifies a substance as a possible allergen, but it doesn’t mean you necessarily will have symptoms when exposed to it.
At-home allergy tests
At-home tests require taking a sample of blood yourself—either in a lab or sometimes by applying a drop of blood to paper in a kit—and then sending the sample off to be analyzed.
While at-home tests may seem comfortable, Dr. Parikh and Dr. Soffer firmly recommend against home test kits as they frequently lead to misdiagnosis of allergy. According to Food Allergy Canada, they are inaccurate, the outcomes may not be clear, and they can be pricey. “You need to be trained in interpretation and can misdiagnose yourself,” Dr. Parikh says. “Also, many at-home tests are not graded or evidence-based.”
Allergy treatments
Depending on the kind of allergy you have (environmental, food etc.), an allergist has numerous distinctive treatment choices that they will tailor to the individual patient, explains Dr. Soffer.
Environmental controls
Blocking the pollen and minimizing time spent outdoors during allergy season, avoiding pet dander, and keeping your home clean and free of mould, dust, smoke, and pests like mice and cockroaches, can be especially important in minimizing allergies, says Dr. Parikh.
Other steps you can practice can incorporate swapping out air filters (preferably HEPA) as suggested, using air purifiers in your home, rotating bed linens frequently, opting for hypoallergenic dogs and cats (or no pets at all), using a proper mattress and pillow covers, and buying hypoallergenic products when available.
Immunotherapy/allergy shots
Immunotherapy/desensitization is a simple method of treating allergies, particularly allergic rhinitis (hay fever), asthma, and eczema. Immunotherapy can resemble allergy shots, which include injecting an extract of the allergen into the arm of a patient, or treatment with drops in the mouth.
It can be effective for people suffering from long-term allergies, as they are the only remedy that can truly desensitize the immune system to counter allergies from occurring. They work properly for some kinds of allergies than others and can include a long-term commitment to the treatment over time.
Medication
There are several medications, both prescription and over-the-counter, to treat allergy symptoms. “One common misconception is that allergic rhinitis is best treated with oral antihistamines,” says Dr. Soffer. “In truth, the best and primary treatment is steroid nasal sprays,”
Allergy prevention
Dr. Soffer supports that one of the most significant ways of preventing allergies from developing is exposing children to allergenic foods as early as possible. “We know that in children who have a high risk of developing peanut allergy, by introducing peanuts at four to six months [of age], parents can dramatically reduce the risk of peanut allergy,” he says.
Dr. Parikh recommends that you should try to reduce exposure to air pollution as well as avoid over-sanitizing with chemicals.
