Allergy: What is allergy? Types, Causes, Symptoms, Treatments @DocOnline (2024)

What We treat

About Allergy

An allergy is a medical condition in which the body’s immune system reacts abnormally to a foreign substance. The substance that causes the allergy is called an allergen.

Allergic diseases have been rapidly increasing since the last few decades affecting 20% to 30% of the total population in India. The common allergic disorders in India comprises of asthma, allergic rhinitis, eczema, anaphylaxis, drug, food, insect allergy, and urticaria.

Causes of Allergy

Interaction of Genetic and environmental factors leads to the development of the allergy

Genetic predisposition
Environmental Factors: A broad range of allergen has been found in India owing to climatic variation, diverse vegetation, and different food habits
- Exposure to allergens or irritants may trigger the allergic reaction
  - Dust mite droppings
  - Animal dander
  - Pollens grains
  - Fungal spores
  - Insect sting/bites
  - Latex (natural rubber)
- Diet
- Medications
- Pollutant
  - Tobacco smoke
  - Exhaust fumes
- Exposure to microorganism [bacteria and viruses] during childhood

The major routes of allergen exposure in India are

Inhalation (airborne pollen grains triggers asthma)
Contact (contact dermatitis)
Ingestion (food allergy)

Symptoms of Allergy

The degree of an allergic reaction may vary from mild to severe. The body reacts differently to different allergens

Common symptoms experienced in an allergic reaction are:

Itchy skin, rash, hives (urticaria)
Watery eyes
Sneezing
Difficulty in breathing
Swelling of body parts exposed to the allergen
Stomach ache
Vomiting

Anaphylaxis (swelling of the lips, tongue, and throat, fainting) is an extreme form of allergy, which needs immediate medical attention.

Types of Allergies

Allergy Types	Symptoms	Treatments
Food Allergy	Vomiting, stomach pain, rashes	Avoid Allergen food entirely
Skin allergy	Rashes, hives, itchy bumps	Take a cold showerApply calamine lotionTalk to Doctor
Dust allergy	Sneezing, coughing, teary eyes	Wear a mask while cleaningUse clean pillows and linens
Insect Allergy	Pain, redness, rashes	Avoid insectsSee the doctor
Drug Allergy	Rash, urticaria, shortness of breath	Avoid triggersAntihistamines or oral /injected corticosteroids under supervision in a hospital or clinic
Allergic rhinitis	Running nose, nasal block, sneezing	Stay indoors during the pollen seasonTalk to your GP

Food Allergy

It is an allergic reaction to food or substance in food. Common foods found to cause allergy are Legumes (Kidney beans, Black gram), seafood (prawns), eggplant, milk, egg.

Signs and Symptoms of Food Allergy

Body Parts	Signs and Symptoms of Food Allergy
Gastrointestinal tract	Vomiting, Stomach cramps, bloating, diarrhea
Skin	Rash, Hives
Cardiovascular system	Dizziness, fainting, weak pulse
Respiratory tract	Cough, shortness of breath
Other	Swelling of the lips, face, and throatAnaphylaxis

Skin Allergy

Eczema (Atopic dermatitis): Itchy dry red skin due to exposure to allergens and food
Contact Dermatitis: An allergic reaction due to contact of skin with an irritant or an allergen may cause a red rash, blisters, itching, cracking, scaling and burning
Hives (urticaria): Raised, itchy bumps on the skin due to food, insect bite, medications
Angioedema: Swelling in deep layers of skin due to allergic reactions to food, medications, insect bites

Dust allergy

Allergy due to dust mite, pollen grains, animal dander or fungal spore.

Insect Allergy

Allergy due to insect stings (bees, wasps) and bites (Mosquitoes, bedbugs, fleas).

Drug Allergy

Allergic reaction due to intake of liquid, pill or injectable form of medication.

Allergic rhinitis (Hay fever)

Seasonal (during pollen season) or Perennial ( throughout the year) allergic rhinitis occurs due to airborne pollen grains, dust mites, animal fur, fungal spores.

Management of Allergy

Diagnosis: Types of Allergy Tests

The 3 main tests for allergy are the skin prick test, blood test, and patch test.

Treatment of Allergy

The ideal solution is to stay away from the allergen that you know you are allergic to. However this is not always possible and treatment includes anti-allergic drugs like antihistaminics, decongestants, and steroids.

It is important to know about your allergies before you get affected. If you are not sure, or the symptoms are not subsiding then consult a doctor online to discuss your problems.

FAQ

What are the 10 most common allergies?

Pollen grains, fungal spores, dust mites, animal dander, certain foods, drugs/medications, chemicals in cosmetics, perfumes, and insects.

What causes allergies?

The body’s immune system reacts abnormally to an irritant or an allergen to cause an allergic reaction.

Are allergies dangerous?

Allergies are usually not dangerous but it can sometimes cause anaphylaxis which is a life-threatening condition.

What are the 4 types of allergic reactions?

Type I (Immediate hypersensitivity), Type II(Cytotoxic reaction), Type III(Immune complex reaction), and Type IV (Delayed hypersensitivity) reactions.