Other names: Allergy; Dust Mite Allergy
Allergies are an overreaction by your immune system to a substance or food that is not considered harmful to most other people. Substances that cause allergies are called allergens or “triggers”.
What Causes Allergies?
When you have allergies, your immune system mistakes normally harmless substances for dangerous invaders and produces antibodies to fight them. These antibodies release chemicals, such as histamine, that cause allergy symptoms.
The most common allergens are:
- Animal fur or hair (such as that from cats, dogs, horses, or rabbits)
- Dust mites
- Food, especially cow’s milk, eggs, peanuts, seafood, soy, tree nuts (almonds, Brazil nuts, cashews) and wheat
- Insect stings
- Latex
- Medicines
- Mould
- Pollen.
An allergen for one person may not cause any problems in another person. There is a link between allergy and asthma.
What are the Symptoms of Allergies?
Reactions to the same allergen vary among individuals and depend on how the allergen entered the body (for example, being bitten by a mosquito causes a localized reaction on the skin whereas exposure to pollen may cause a tickly throat and itchy eyes).
Symptoms may include:
- Abdominal pain, diarrhea, nausea, vomiting (food allergies)
- Areas of swelling and redness where a person has been stung or bitten (for insect bites/stings)
- Cough, chest tightness, wheezing or shortness of breath
- Itching of the nose, eyes or roof of the mouth
- A skin rash or hives, usually accompanied by body-wide itching
- Runny, stuffy nose
- Sneezing
- Swelling of the lips, tongue, face, or throat
- Tingling of the mouth
- Watery, red or swollen eyes (conjunctivitis)
- Wheezing.
Some types of allergies can trigger a severe reaction known as anaphylaxis. Symptoms of anaphylaxis include:
- Loss of consciousness
- A drop in blood pressure
- Severe shortness of breath
- Skin rash
- Lightheadedness
- A rapid, weak pulse
- Nausea and vomiting.
When Should I See a Doctor for my Allergies?
Many allergies can be effectively treated with over-the-counter medications. See your doctor if you have persistent allergies that are interfering with your day to day life if you have severe reactions, or over the counter, remedies are not effective.
People who develop anaphylaxis should always carry an epinephrine auto-injector 24 hours a day and know how to use it. People should also visit the emergency department after using the auto-injector to ensure symptoms don't return when the effects of the injection wear off.
How Are Allergies Treated?
Treatment depends on what is the most troublesome or predominant symptom. Treatments may include:
- Antihistamines (oral, nasal, topical)
- Corticosteroids (oral, nasal, topical)
- Decongestants (oral, nasal)
- Saline nasal rinses
- Immunotherapy.
People with known allergies should try and avoid known triggers and wear a medical alert bracelet (or necklace) that lets others know that you have a serious allergy in case you have a reaction and you're unable to communicate.
