Allergies – Types, Symptoms, and Treatments


Every time an individual goes near animals, their eyes become watery and sneezing occurs. And every time a person visits a dirty place, they tend to sneeze and experience a runny nose. Well, these individuals might have allergies. 

What are allergies?

Allergies arise when a person reacts to environmental elements that are typically safe for most people.

Allergens are substances that cause allergies. Some commonly known allergens are dust mites, animals, pollen, insects, ticks, mould, food and some medications.

Atopy is the genetic predisposition to develop allergic diseases. Atopic individuals may experience an immune response that results in allergic inflammation when they are exposed to allergens.

Types of Allergy

Drug Allergy

Drug allergy occurs when the body’s immune system becomes sensitive to a component of the medication taken. The immune system views the allergens as invaders and releases chemicals to protect itself. The symptoms are similar to other allergic reactions.

Whether a medication is taken as a liquid, pill or injectable, people with drug allergies may still experience symptoms. Seeing an allergist is advisable if a person feels uncertain about the symptoms and to know which medications to take.

Food Allergy

When the body’s immune system reacts unusually to a particular food, it is known as a food allergy. Food allergies arise when the immune system, the body’s line of defence against infection, misinterprets food proteins as a danger. Allergy symptoms are frequently minor, but they can also be very dangerous. 

Several chemicals are consequently released after consuming an allergic food. These substances are responsible for allergic reaction symptoms.

Though almost any food can trigger an allergic reaction, certain foods are the leading causes of food allergies. Gluten allergy is widely noticed in people.

The following foods tend to trigger allergic reactions:

  • Eggs 
  • Milk 
  • Shellfish
  • Fish
  • Tree nuts
  • Peanuts
  • Some fruits and vegetables

Insect Allergy

An abnormal response to insects is known as an insect allergy. It might be a response to stings, bites or bug faeces inside the house.

The severity of the reactions can range from minor to fatal. The trigger for the allergic response may be the venom from a sting or fluid from a bite. The insects can cause reactions at any time of the year. They may cause asthma to flare up.

Stinging insects that cause allergies:

  • Fire ants
  • Wasps
  • Honeybees
  • Hornets
  • Yellowjackets

Biting insects that cause allergies:

  • Mosquitoes
  • Blackflies 
  • Kissing bugs
  • Fleas
  • Horseflies

Insects sometimes leave behind materials in the home that cause reactions. They are:

  • Caddis flies
  • Cockroaches
  • Lake flies
  • Midges

Latex Allergy

Latex allergy is an allergic reaction to particular proteins in latex made of natural rubber. An immune system response occurs to proteins in natural rubber latex, a product made from rubber tree fluids.

The symptoms can range from a minor skin rash to shock, which could be fatal. If a person has a latex allergy, staying away from latex rubber is advisable. 

Antihistamine drugs can ease minor reactions. Emergency care may be necessary for severe reactions.

Mold Allergy

Mold allergy is an uncharacteristic allergic response to mold spores. When someone has a mold allergy, their immune system overreacts when exposed to mold at work, home or outside.

Coughs, itchy, watery eyes and hives are some symptoms. Wheezing and breathing difficulties are common in asthmatics during mold allergy.

Avoiding exposure to mould is part of the treatment. Asthma management can be aided by medications like antihistamines, nasal sprays and allergy shots.

Pet Allergy

Proteins in an animal’s dander or dead skin cells are most likely to cause allergies as they can be shed frequently. Pet dander can trigger an allergic reaction at any time of year, but it is more prevalent during winter when people spend more time inside. 

Consulting an allergist is best if an individual suspects that they may be allergic to animals. Dogs are prone to getting into various places, and their fur tends to collect proteins, dander and pollen. 

Although many breeds, including poodles and Portuguese water dogs, are claimed as hypoallergenic dogs, evidence from scientific studies indicates that no dog breeds are truly allergy-free.

Compared to dogs, cats are more likely to trigger an allergic reaction. Although cat dander allergies are frequently to blame, cats also have several other allergens on their bodies and saliva. That’s right, cat allergies can be brought on by the saliva that the cat uses to groom itself because it contains allergen-causing proteins.

Pollen Allergy

One of the most common causes of allergies or hay fever is pollen. A pollen allergy is one of the most prevalent outdoor allergies in the world because of how widespread it is. Statistically, one in every seven individuals worldwide has a pollen allergy.

Trees, grasses, and weeds are the primary sources of pollen that causes allergies.

  • Trees: Early flowering species like alder, birch, hazel and ash have pollen that is particularly allergenic. Allergy to birch pollen is more prevalent.
  • Grasses: The Poaceae, also known as grasses, are primarily to blame for causing allergies to grass pollen.
  • Weeds: Ragweed and mugwort are two weeds that are very allergenic.

Symptoms of Allergies 

Mild allergy symptoms 

Watery eyes

When the allergens affect the eyes, eyes tend to burn, becoming red and watery, making the eyelids swell.

Runny nose

When an allergen, like pollen or dust, first enters the body, it irritates the sinuses and the lining of the nose. As an allergic reaction, the nose begins producing a lot of mucus which is cleared through the running nose.


Postnasal drip can develop when an allergen that irritates the nasal lining enters the body. This runny mucus causes a tickle in the throat, resulting in coughing as it drips from the nose down the throat.


Rashes occur when the skin gets in contact with an allergen. 

Localised itching

Histamine is a chemical that the body releases as an immune response. It brings about itching and redness after an insect bite or as an allergic reaction to pollen, latex, medications and food. Pollen, mold, animal fur or dust mites might cause itchy eyes.


Allergies frequently cause nasal congestion and runny nose as allergens come in contact with nasal tissues and cause irritation.

Moderate Allergy Symptoms

Widespread itching

Sudden and intense itchiness on the skin is an allergic reaction post-exposure to allergens. A person feels the urge to itch the whole body. Redness on the skin and hives also accompany this symptom.

Difficulty breathing

Allergies trigger the immune system by producing an excess of immunoglobulin E, which results in swollen airways. Breathing becomes difficult with decreased oxygen supply, and wheezing along with shortness of breath occurs.

Severe Allergy Symptoms


On exposure to allergens, the body releases histamines, causing itchy bumps and patches known as hives.

Abdominal pain

People experiencing allergies frequently have gastrointestinal symptoms such as abdominal pain.


Hives or a rash may appear if histamine is released into the skin. People experience cramps, diarrhoea or stomach pain if histamine is released into the gastrointestinal tract. Symptoms differ from person to person.

Vomiting and Diarrhoea

Vomiting and diarrhoea are due to the release of histamines.

Mental confusion or dizziness

Pollen, dust or pet dander can trigger allergic reactions, causing dizziness in a person. Headaches also accompany this.

Treatments for Allergies 


Some people choose not to take allergy medications because they believe their symptoms are not severe. This may lead to issues like ear infections or sinus problems. It’s better to not take a chance. 

A wide variety of prescription and OTC medications are available to treat allergy symptoms. Here are a few allergy medications,

  • Nasal corticosteroids, also known as nasal sprays, reduce swelling. An itchy, runny and stuffy nose might result from swelling. They are the best treatments for nasal allergies. 
  • Antihistamines work by blocking histamine, which causes allergic swelling to occur. They can relieve hives, sneezing, itching and runny nose. They come as liquids, tablets that melt in the mouth, pills or nasal sprays. Antihistamines treat seasonal and indoor allergies.
  • Mast cell stabilisers prevent the release of histamines that cause allergies. This can treat watery, itchy eyes or a runny, itchy nose. Mast cell stabilisers come as nasal sprays or eye drops.
  • Decongestant work by constricting swollen nasal membranes, thereby reducing stuffiness.
  • Oral corticosteroids cure extreme allergic reactions and reduce swelling.
  • Corticosteroid ointments work against rashes and itchiness.


This is a preventive therapy for allergic reactions to things like grass pollens, house dust mites, and bee venom. 

Immunotherapy involves giving the patient progressively higher doses of the substance or allergen they are allergic to. 

The immune system becomes less sensitive to the allergen through frequent exposure, most likely due to the production of a blocking antibody that reduces allergy symptoms when the allergen is re-exposed.

Subcutaneous immunotherapy (SCIT) is an allergy shot and is the most popular and efficient type of allergy immunotherapy. 

An alternative method of treating allergies without injections is sublingual immunotherapy, which is administered under the tongue.

Emergency epinephrine

A combination of emergency medical care and epinephrine injection treats allergic reactions that are life-threatening and brought on by foods, latex, medications, insect stings and other causes.


Patch tests

A patch test is done to find the root cause of a potential allergic reaction on the skin. The allergic reaction is contact dermatitis. 

During the patch test, the healthcare professional apply a few drops of an allergen to the skin on the arm before bandaging the area. Alternatively, the doctor might apply a patch (bandage) with the allergen. 

The patient should leave the bandage on for 48 to 96 hours and revisit the doctor. The bandage is then taken off so that the healthcare provider can examine the skin for any reactions or rashes.

Blood test 

Blood tests for allergies are of two types,

  • Total IgE test – The test determines the total amount of IgE antibodies in the blood. A high total IgE test result indicates that the person might have an allergy. 
  • Specific IgE test – This test measures the IgE production in response to a single allergen. Each allergen that might be causing the allergies is tested separately. A high specific IgE test result for a particular allergen indicates that the person might be allergic to that allergen.

Both tests cannot determine the severity of the allergy.

Skin prick test 

During the skin prick test, the doctor may prick the forearm or back with 10 to 50 different potential allergens using a thin needle. 

Alternatively, the healthcare professional might apply tiny droplets of potential allergens to the skin and then use a tool to lightly nick and scratch the area, allowing the liquid to seep into the skin. 

Typical reactions like redness happen 15 minutes after exposure. A rash or round spots could be the reaction. This test looks for penicillin, food and airborne allergy symptoms.

Prevention of Allergies 

Avoiding allergens and taking prescribed medications prevent allergic reactions. Preventing allergies can commence at birth by strengthening the immune system.

Exclusive breastfeeding to 4–6 months of age

Evidence suggests that exclusively breastfeeding for at least four months in high-risk infants and delaying the introduction of complementary foods until four to six months prevent the development of allergies. 

Use of hydrolysed milk formulas 

Infants at high risk for allergic disease may benefit from supplemental hydrolysed formulas. When starting formula feeding for infants who are at increased risk for allergies, certain extensively hydrolysed casein and certain partially hydrolysed whey formulas are suitable.

Complications of Allergies 

Suddenly narrowed airways

The muscles surrounding the airway can spasm in response to exposure to some irritants or allergens. This can narrow the bronchi or other airways. The narrowing makes it challenging to breathe in and out.

Increased heart rate

An increase in heart rate is noticeable in patients with allergies. The rate of heart attack was also found to be high in pollen-allergic individuals.

Possible swelling of the tongue and mouth

Mouth and tongue issues can result from oral allergies. After consuming certain foods like melons, pineapple or apples, people with food allergies may experience swelling of the tongue. 

Allergic reactions to bee stings, specific medications or other oral products also cause tongue swelling. 


Asthma often co-occurs with allergies since the substances that trigger allergies are known to cause signs and symptoms of asthma.

Cold and cough

Cold and cough often occur as an allergic reaction. Allergy can also crop out in response to cold temperatures, which is known as cold urticaria. 


Chronic bronchitis is frequently also known as allergic bronchitis and may be brought on by exposure to allergens. Cigarette smoke is one of the usual triggers.

Allergies and babies

Infants in their first year of life rarely develop allergies to inhalable substances, such as pollen, pet dander, mold and dust mites. 

A person with a family history of allergies, hay fever, asthma or eczema is more likely to have a baby who develops food allergies and eczema.

Living with allergies

A combination of immunotherapy, allergy medications and allergen avoidance can effectively relieve allergy symptoms.

The best way to manage allergies is to become aware of the triggers and allergens, stay away from them and take the medication as directed. 

When to see a doctor?

People deal with allergies in different ways. Visiting or not consulting a doctor is the personal choice of an individual. However, in extreme allergy cases, doctor consultation becomes mandatory. 

The following are the signs that indicate the necessity to visit an allergist.

  • When over-the-counter medications don’t help
  • During severe allergy/anaphylaxis symptoms 
  • Symptoms affect day-to-day life
  • Continuous sick feeling


Allergies are an immune response to specific environmental triggers, posing severe health issues in some individuals.

Despite the fact that there are medications for treating allergy symptoms, immunotherapy—which modifies the patient’s response to the allergen—is the only effective treatment for allergies. 

Patients who don’t improve after taking their regular medications typically receive immunotherapy. To better treat allergies and find a cure, scientists are still researching allergies worldwide.


How can I prevent allergies naturally?

Staying away from the allergens causing the allergies is the best way to prevent the reactions. Herbal remedies are also known to be effective.

How can I stop my allergy?

Over-The-Counter medications can help stop allergic reactions. Home remedies and topical creams work on treating the symptoms.

What is anaphylaxis?

Anaphylaxis is a severe allergic reaction that could be fatal. The reaction can happen seconds or minutes after exposure to an allergen.

What is pollen?

Pollen is a fine powder that seed plants produce. These are so tiny that they are more likely to cause allergies.

How are allergies diagnosed?

Diagnosing allergies can be done through blood tests, patch tests and skin prick tests.

What are allergy medicines called?

Antihistamines are medicines frequently prescribed to treat allergy symptoms.

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