- Signs and Symptoms
- Risk factors and Causes
- Diagnosis and Testing
- Possible Complications
Allergy is simply an over-reaction of body upon exposure to certain substances (allergens). Those substances can be present in food, air, environment, insect bite and some medications.
Allergy could be from mild skin itch or sneezing to complicated life-threatening reactions.
Allergens are substances that trigger or cause allergic reactions when sensitive people are exposed to them. Not every person is affected with allergy; people who are sensitive to certain substances experience allergy to those substances.
Those substances can be present anywhere such as
- Plant pollen and grass
- Some substances in food – such as milk products (cheese, butter), nuts, eggs, some types of fishes, colour pigments in the process food
- Dust mites (tiny insects)
- Particles in air we breath
- Insect bites or stings
- Medicines e.g. Aspirin, some Antibiotics
- Animal fur or dander (cats, dogs)
- Mold, latex and some other chemicals like detergent powder
Even a tiny quantity of allergen can trigger allergic reaction.
Allergies are quite common, especially in children. Most people experience some mild allergies a few times in their entire life-span. Some allergies go away as the child gets older but some allergies stays for the entire life.
Allergy affects daily activities and it could be really disturbing.
Naturally, immune system produces antibodies to defend against attacking microorganism (such as bacteria, viruses) and other foreign substances. Allergy occurs when the immune system mistakenly reacts to some foreign substances (allergen) by producing antibodies. Usually those foreign substances are harmless however, the immune system of sensitive person by-mistake recognizes them as harmful for the body. On repeat exposure to the same allergen, antibodies trigger allergic reaction causing skin rash, inflammation of airways, or more severe reaction.
Severity of allergies vary from one person to other. It could range from minor skin irritation to serious reaction referred as anaphylaxis.
Anaphylaxis (or anaphylactic reaction) is a severe type of allergic reaction that can be potentially life-threatening. Emergency or ambulance services should be called to transport the patient to the nearest hospital immediately.
Anaphylaxis is rapid in onset and may cause death if proper medical care is not available on time. It typically starts with an itchy rash, fast heartbeat and swelling of tongue. The patient suffers with difficulty in breathing, swallowing, low blood pressure and losing consciousness. These symptoms could show up within minutes to hours.
Anaphylaxis can be caused by any substance, however commonly occurs due to exposure to some foods, insect bites, medicines, snake stings, latex exposure and exercise.
Patient should be taken immediately to the hospital emergency room and epinephrine injection is administered, if required. Patients who had suffered with anaphylactic reaction earlier are required to carry epinephrine auto-injector to be given if it occurs again.
Allergic reaction may occur within a few minutes to few hours after exposure to allergen.
Some common symptoms include
- Runny nose or blocked nose
- Watery eyes
- Red or itchy eyes
- Skin rash, hives or red raised rash
- Coughing and wheezing
- Symptoms of eczema, dermatitis
- Worsening of asthma
- Swelling of lips, face, throat or tongue
- Skin flake or peel
It is not fully known why some people develop allergy. However, family history of allergy, asthma or eczema are to blame. Allergy occurs when immune system mistakenly react with substances, which are actually harmless.
There are various kinds of allergens, some very common allergens are listed below
Some people are allergic to dust mites. Dust mites are tiny creatures and house dust mites are common cause of allergic symptoms. They are usually present indoors and occupy furniture, mattresses, curtains, carpets, bedsheets and blankets.
Allergies due to food varies from one person to another. Food allergies are usually caused by milk product such as cheese, butter, eggs, some fruits, nuts, fish, meat and much more.
Tree Pollen and Grass
Some people are allergic to tree pollen and grass. Allergy to tree pollen is known as hay fever.
Stings and Insect Bites
Stinging insects commonly include bees, wasps and hornets. Sting is due to venom, which is injected into the skin by the insect. Biting insects include flies, fleas, ticks, mites and bedbugs. Bites and stings of these insects may cause allergic reaction in some people due to venom deposited into the skin.
Animal dander comprises of tiny hair or skin that may cause allergy in people who are allergic to them.
There are certain medications that cause allergic reactions, such as aspirin, ibuprofen and some antibiotics.
Molds are small particles, which are released in the air, these are inhaled by people and cause allergic reactions in them.
Chemicals used in Homes
Various chemicals in hair dyes, soaps and detergents can cause allergy in some people.
The doctor may ask questions about the symptoms, when they occur, how those symptoms happen and whether they occur after exposing to certain food or other substances.
In cases of severe allergies, the doctor may order some lab test to identify the allergen.
Testing may include:
Skin prick test
Patient is exposed with the suspected allergens in minute quantity to see the allergic symptoms
Blood samples are collected to test specific antibodies (IgE) against specific allergens
Diet elimination test
In case of suspected food allergy, patients are asked to stop eating certain type of food such as dairy products like milk, yogurt, butter and cheese and after a couple of weeks gradually add the above items in the diet one by one.
Using a number of measures, one can easily manage allergic reactions at home. Some of those measures are given below
Avoidance from the Allergen
The best approach is to avoid exposure to the allergens. In many cases it is possible, but in some cases it is very difficult to avoid.
Food allergies can be avoided if the patient knows what triggers his allergic reaction. However, some allergy triggers are difficult avoid completely such as allergy with dust mites.
Antihistamines are drugs are used to treat allergic reaction at home. These drugs could be taken when symptoms start showing up. These medicines could also be taken before being exposed to an allergen, in order to stop the reaction from occurring.
Decongestants are drugs, which relieve congestion or blockage in the nose and sinuses. Various substances could be used at home for this purpose, which include drops, sprays, tablets, inhalers and capsules.
These medicines should be used as per doctor’ instructions. They are usually not prescribed for long-term use. Steroids come in many dosage forms such as sprays, creams, inhalers, tablets and drops.
Risk of having certain medical problems could be increased when an allergic reaction occurs. Some of the complications include:
Asthma is triggered by exposure to an allergen affecting airways and breathing. This is known as an allergy-induced asthma.
A person is at increased risk of having allergy induced reaction during severe allergies. Most common triggers of anaphylaxis are insect stings, various medications and foods.
Infections in Ears, Lungs, Sinus
In case of allergy causing congestion or blockage in the nose or sinuses or asthma, those patients are more sensitive to infections of ears and respiratory organs.
Some allergy could result in fungal sinusitis