OverviewKey FactsCausesSymptomsRisk factorsDiagnosisPreventionCelebs affectedSpecialist to visitTreatmentHome-careComplicationsAlternatives therapiesLiving withFAQsReferences
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Allergic conditions

Allergic conditions

Also known as Hypersensitivity


Allergies are caused when the body’s immune system responds abnormally to an external trigger known as ‘allergen’. These allergens are present in our environment but do not usually incite an immune response in other people. While in some people, the body’s immune system generates antibodies against these foreign bodies or allergens. This causes inflammation and leads to various symptoms that can range from being mild to quite severe.

The symptoms of allergy vary such as mild sneezing, runny nose, swelling of face, swelling of the tongue, skin rash, itching, and difficulty in breathing, etc. Anaphylaxis is a severe reaction to any type of allergy which can be life-threatening, if not promptly treated.

Allergies are widely prevalent across the world. These can be caused due to different types of allergens such as dust, molds, mites, foods like nuts, fish, and medicines like penicillin. Clinical treatment for allergies is suggested with antihistamine medicines, steroids, and OTC preparations to provide relief from symptoms.

Key Facts

Usually seen in
  • Children below 15 years of age
Gender affected
  • Both men and women but more common in women
Body part(s) involved
  • Immune system
  • Skin
  • Lungs
  • Eyes
Mimicking Conditions
Specialists to consult
  • Immunologist
  • Allergist
  • Dermatologist
  • Respiratory specialist
  • ENT specialist
  • Intensive care specialist.
Related NGOs

Causes Of Allergy

Allergies are caused when the body’s immune system responds abnormally to an external trigger known as ‘allergen’, which does not usually incite an immune response in most other human beings. When the allergen comes in contact with the human body, the immune system activates a response system by producing IgE antibodies. Usually, this immune response is not harmful, but an extreme reaction of the immune system may lead to the formation of a chemical called histamine that causes the various symptoms of allergy.

There are innumerable substances that can cause allergies. The most commonly observed allergens are:
  • Dust
  • Mold
  • Mites
  • Pollen
  • Animal fur
  • Insect bites
  • Latex
  • Foods like peanuts, shellfish, and milk
  • Certain medications like penicillin, and NSAIDs
  • Seasonal changes

Symptoms Of Allergy

There are many different types of allergies, each of them present with different symptoms, such as

1. Skin allergy: Also known as ‘atopic dermatitis’ or eczema, it can cause symptoms like:

  • Redness, itchiness, and pain in the parts of the skin exposed to the allergen. 
  • It may also cause the skin to become flaky and peel off.

2. Allergic conjunctivitis: When an allergen enters the eye and irritates the conjunctival lining, it may cause the following symptoms:

  • Redness in the eyes
  • Puffy eyes
  • Excessive watering of the eyes
  • Itching or burning sensation of the eyes
  • Changes in vision

3. Food allergy: Consuming foods that cause allergy can cause symptoms such as:

  • Tingling in the mouth 
  • Puffing of the face 
  • Swelling of the lips 
  • Swelling of the tongue 
  • Difficulty breathing 
  • Itching all over the body
  • In severe cases, it can cause anaphylaxis

4. Insect allergy: An insect sting can cause allergic symptoms like:

  • Pain, swelling, and redness at the site 
  • Itching all over the body 
  • Difficulty breathing 
  • Chest tightness and wheezing
  • In severe cases, it can also cause anaphylaxis

5. Respiratory allergy: Allergic rhinitis and asthma are types of respiratory allergies. Symptoms of respiratory allergies are:

  • Shortness of breath 
  • Coughing 
  • Wheezing 
  • Chest tightness 
  • Runny nose

6. Medicinal allergy: Certain medications can trigger an allergic reaction and cause symptoms like:

  • Swelling of the face and body 
  • Difficulty breathing 
  • Cough 
  • Chest tightness 
  • Skin rash 
  • Skin itching
  • Anaphylaxis, in severe cases

7. Anaphylaxis: This is a severe reaction to any type of allergy, which can be life-threatening. The symptoms of anaphylaxis are:
  • Anaphylactic shock
  • Severe drop in blood pressure
  • Loss of consciousness
  • Extreme difficulty while breathing
  • Weak and thready pulse
  • Nausea
  • Skin rash
Did you know?
If your kid is scratching the skin very often or if there is a rash on the skin that fails to go away on its own, then it could indicate a skin allergy. Here are some of the common causes of skin allergies in children.
Did you know?

Risk Factors For Allergy

Allergies are widely prevalent across the world and the number of people suffering from allergies is increasing every year. It is estimated that about:
  • 200-250 million people suffer from food allergies
  • 400 million people suffer from allergic rhinitis
  • 300 million people have asthma (allergic reaction due certain allergens like pollen or dust) One-tenth of the population suffers from medicine allergies worldwide

The risk factors for allergy include:
  • A family history, as allergies are hereditary. The risk of developing an allergy increases if your parents or someone in the family has allergies.
  • Occupational exposure to common allergens, such as dust, can also trigger allergies due to repeated exposure to the triggers. 
Did you know?
Although rare, vaccines, specifically individual components of the vaccine, are known to cause allergic reactions. The vaccine components include active immunizing antigens, conjugating agents, preservatives, stabilizers, antimicrobial agents, adjuvants and culture media used in the preparation of the vaccine. These allergic reactions are often mild and subside within some time. But in some cases, these can lead to serious health complications like anaphylaxis and therefore require attention.
Did you know?

Diagnosis Of Allergy 

To evaluate whether a person is allergic to any particular trigger, the doctor may take a detailed history of the onset of symptoms with particular emphasis on the exposure to allergens and how often the symptoms occur. Along with this, the doctor may perform a detailed physical examination to evaluate the symptoms and their probable cause. 

A skin prick test can check for the development of an allergic reaction to the exposure of common allergens via the skin prick. The development of a skin rash or bumps at the test site suggests an allergic reaction.

Laboratory tests to check for the levels of Total IgE are also used to evaluate the possibility of allergies. Other specific tests that may be performed to test for specific allergies include:

Prevention Of Allergy

Allergies by themselves cannot be prevented as they are mostly hereditary. But the harmful effects that occur due to allergy, otherwise known as an allergic reaction, can be prevented. The single most effective way to prevent an allergic reaction is to avoid exposure to the causative allergen.

It is important first to understand and recognize the trigger that causes the allergic reaction. Once the agent is identified, all steps must be taken to avoid exposure to the allergen, wherever possible. For example: 

  • Dust allergy: Using face masks or tying a wet cloth over the nose and mouth while cleaning or dusting an area with excessive dust.

  • Food allergy: Avoiding foods that may cause allergies, even in minute quantities.

  • Medicine allergy: Always inform your doctor if you have had an allergic reaction to any medicine in the past so that the doctor can modify the treatment accordingly.

  • Mold allergy: Molds usually grow in dark enclosed places, devoid of sunlight. To prevent exposure to molds, all areas at home must be adequately ventilated and receive plenty of natural sunlight.

Those who face respiratory problems on and off can benefit by using some natural herbs on a regular basis or as advised. Here are a few natural herbs that will help you fight symptoms of common respiratory allergies.

Celebs affected

Halle Berry
American actress Halle Berry, more famously known as ‘The Bond Girl’, is allergic to shellfish.
Kim Kardashian
American reality TV star Kim Kardashian is allergic to cat fur.

Specialist To Visit

If you get recurrent symptoms such as sneezing, skin rash, or chest tightness in response to being exposed to any particular environmental trigger, you may be suffering from allergies and must seek medical care. You may seek help from an immunologist or allergist. Based on your allergy symptoms, you can also consult:

  • General physician
  • Dermatologist
  • Respiratory specialist
  • ENT specialist

Also, at times, allergic reactions are severe and cause anaphylaxis. At such times, it is essential that the patient seeks prompt medical care at the hospital’s emergency department. The patient may need to be treated by an intensive care specialist.

Consult India’s best doctors online. Click here to book an appointment now.

Treatment Of Allergy

The treatment for an allergic reaction aims to provide symptom relief and long-term management for desensitization of the immune system.

1] Symptomatic relief

1. Antihistamines: These are used to provide relief from allergic reaction symptoms such as itching, swelling, and rashes. They work by blocking the action of histamine, the chemical responsible for allergy symptoms. They may be given orally or applied topically on the skin in a lotion or cream form to provide relief from skin rash and itching. 

Antihistamine eye drops are used to provide relief from eye allergies. Antihistamines can also be administered through the nose to provide rapid relief from nasal congestion, sneezing, runny nose, and other respiratory symptoms. Medicines that belong to this class include:

2. Nasal decongestants: These can also provide symptom relief by reducing nasal congestion and make breathing easier. These include:

3. Corticosteroids: These are available for oral consumption or in an injectable form. They are used to provide rapid relief from mild to severe allergy symptoms such as inflammation and rash. Steroids may also be prescribed as eye drops to help with eye symptoms and skin rashes. Examples of this class of medicine include:


4. Bronchodilators: These are used to provide relief from acute asthma symptoms. Other medicines for inhalation are prescribed as daily maintenance therapy for asthma. Salbutamol is one of the most commonly prescribed medicines in this category.

2] Immunotherapy

For severe allergies or allergies that do not respond to standard medication, immunotherapy may be tried. This involves a series of allergen exposures via injections or tablets over a period of a few years. With time, this helps desensitize the body’s immune system to the allergen and prevents serious allergic reactions.

3] Treatment for anaphylaxis

Anaphylaxis is the most severe form of an allergic reaction that requires immediate medical care. When a patient starts getting an anaphylactic attack, they must be given an injection of adrenaline as soon as possible, and it may need to be repeated at intervals. Symptoms of anaphylactic attack may include dizziness, difficulty in breathing, skin rashes, nausea or vomiting, and fast heart rate. The patient must receive prompt supportive care at the hospital.

Allergies can affect people of all ages, sex, and race. Want to know how to tackle allergies in a risk free way?

Home-care For Allergy

Preventing exposure to allergens is the best way to avoid getting allergic reactions, and this can be achieved by adopting simple lifestyle modifications such as: 

  • Staying away from dusty and moldy areas

  • Covering the nose and mouth with a mask or wet cloth in dusty environments or performing activities like cleaning

  • Ensuring that all rooms of the house get ample natural air and light to prevent the growth of molds

  • Avoiding garden and field visits, if you have pollen allergy or insect allergy

  • Staying away from pet animals, if you are allergic to pet fur or dander (flakes of animal skin)

  • Avoiding foods that cause allergies like nuts, milk, certain types of fish and mushrooms

  • Avoiding contact with foreign bodies such as metals or detergents that trigger skin allergies

How to care for troublesome symptoms

If you have an allergic reaction that causes troublesome symptoms, you can care for yourself by doing the following things:

  • Do not panic. 

  • Immediately withdraw contact from the allergen.

  • If you have mild symptoms like a runny nose, sneezing, or a mild rash, take OTC preparations to relieve the congestion. You can also use emollient cream to relieve skin rash.

  • Using a saline nasal rinse can help relieve symptoms such as nasal congestion

  • A cold compress (ice pack) or shower can help reduce the symptoms of skin rash or burning sensation.

  • You must always carry an emergency epinephrine shot with you, which can be used in emergency cases of anaphylaxis.

Did you know?
Temperature, time of day, humidity, and rain can affect levels of the pollen count. If you have allergies, the best time to go outside is right after heavy rains. Pollen counts run lowest on chilly, soggy days. Stay prepared with anti-allergic medicines.
Did you know?

Complications Of Allergy

If allergy is left ignored or unnoticed, it can lead to various complications such as:

Anaphylaxis: At times, the allergic reaction may be severe and may cause an episode of anaphylaxis, which can be fatal if not treated in time.

Asthma: People with allergic disorders are more prone to develop asthma, an obstructive airway disease characterized by wheezing, cough, and breathlessness. Allergens may also cause worsening of symptoms of asthma.

Recurrent infections: Allergies make a person more prone to recurrent bacterial infections, such as sinusitis, pharyngitis, etc.

Respiratory allergies, especially asthma and nasal allergy (also called allergic rhinitis) are increasing worldwide, particularly in children. Here’s more information on respiratory allergies and asthma.

Alternative Therapies For Allergy

: According to Ayurveda, allergies occur when there is an imbalance of the three doshas - vata, pitta, and kapha doshas. The Ayurvedic approach believes in avoiding exposure to common allergens and maintaining a balance of the three doshas. 

Ayurveda suggests detoxification procedures, such as ‘Nasya Chikitsa’, to help with symptoms of respiratory allergies. Herbal preparations, such as tulsi, ginger, ashwagandha, and triphala may help ease symptoms of a mild allergic reaction.

Homeopathy: Homeopathic medicines are seen to improve the over-sensitized immune system and thus act as an immunomodulator or immunoregulator. Homeopathy not only treats the disease permanently by correcting the immune response and that too without side-effects like dizziness and drowsiness.

Some of the common homeopathic medications recommended for allergic rhinitis are:

Yoga: Breathing exercises such as pranayam may be beneficial, providing relief from respiratory symptoms of an allergy, such as nasal congestion, runny nose, and breathlessness.

Living With Allergy

A person with allergies may find it difficult to lead a completely symptom-free life. Even the slightest exposure to the allergens can trigger a severe allergic reaction and even anaphylaxis. With treatments, the intensity of the allergic reactions can be reduced to some extent.

A person with allergies may find it difficult to perform some day-to-day activities like cleaning, dusting, etc. There may be certain dietary restrictions also. The person may require alternative medicines in case a person takes certain medicines which may cause allergic complications.

People with severe allergies are recommended to carry an emergency epinephrine shot at all times with them. This can be life-saving in the case of a severe episode of anaphylaxis.

Frequently Asked Questions


  1. Janeway CA Jr, Travers P, Walport M, et al. Immunobiology: The Immune System in Health and Disease. 5th edition. New York: Garland Science; 2001. Chapter 12, Allergy and Hypersensitivity.External Link
  2. Galli SJ, Tsai M, Piliponsky AM. The development of allergic inflammation. Nature. 2008 Jul 24;454(7203):445-54External Link
  3. Holgate, S., Polosa, R. Treatment strategies for allergy and asthma. Nat Rev Immunol 8, 218–230 (2008).External Link
  4. Chang HJ, Burke AE, Glass RM. Food Allergies. JAMA. 2010;303(18):1876. doi:10.1001/jama.303.18.1876.External Link
  5. Wheatley LM, Togias A. Clinical practice. Allergic rhinitis. N Engl J Med. 2015 Jan 29;372(5):456-63.External Link
  6. Jensen-Jarolim E, Untersmayr E. Gender-medicine aspects in allergology. Allergy. 2008 May;63(5):610-5.External Link
  7. Chung EH. Vaccine allergies. Clin Exp Vaccine Res. 2014;3(1):50-57. External Link
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