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Allergy – Full Chapter Notes (Class 7 Science / ICSE Level)


1. Introduction to Allergy

An allergy is a condition in which the body’s immune system reacts strongly to certain substances that are usually harmless.

These substances are called allergens.

When an allergen enters the body, the immune system treats it as harmful and produces a reaction, which causes symptoms like sneezing, itching, swelling, or rashes.


2. What is an Allergen?

An allergen is any substance that can cause an allergic reaction.

Different people may be allergic to different substances.

Common Allergens

  • Dust
  • Pollen
  • Pet hair
  • Certain foods
  • Medicines
  • Insect stings
  • Mold

3. How Allergies Occur

When an allergen enters the body:

  1. The immune system identifies it as harmful.
  2. The body produces chemicals like histamine.
  3. Histamine causes inflammation and irritation.
  4. This leads to allergic symptoms.

4. Types of Allergies

Allergies can affect different parts of the body.


1. Respiratory Allergies

These affect the nose and lungs.

Examples

  • Sneezing
  • Runny nose
  • Coughing
  • Breathing difficulty

One common respiratory allergy is .


2. Skin Allergies

These affect the skin.

Symptoms

  • Itching
  • Redness
  • Swelling
  • Rashes

Examples include:


3. Food Allergies

Some foods can cause allergic reactions.

Common Food Allergens

  • Milk
  • Eggs
  • Peanuts
  • Seafood
  • Wheat

Symptoms

  • Vomiting
  • Stomach pain
  • Swelling of lips
  • Skin rashes

4. Drug Allergies

Certain medicines may cause allergies in some people.

Examples:

  • Antibiotics
  • Painkillers

Symptoms may include:

  • Skin rash
  • Fever
  • Breathing problems

5. Symptoms of Allergy

Common symptoms include:

  • Sneezing
  • Runny nose
  • Itchy eyes
  • Skin rashes
  • Swelling
  • Difficulty breathing
  • Watery eyes

Severe allergic reactions can be dangerous.


6. Severe Allergy (Anaphylaxis)

A very serious allergic reaction is called .

Symptoms

  • Sudden drop in blood pressure
  • Swelling of throat
  • Difficulty breathing
  • Dizziness

This condition requires immediate medical treatment.


7. Causes of Allergy

Allergies can occur due to many reasons.

Common Causes

  • Dust mites
  • Pollen from plants
  • Animal fur
  • Certain foods
  • Insect bites
  • Pollution
  • Chemicals

8. Diagnosis of Allergies

Doctors use different methods to identify allergies.

1. Skin Test

A small amount of allergen is placed on the skin to observe the reaction.

2. Blood Test

Checks immune response to allergens.


9. Treatment of Allergies

Treatment depends on the type of allergy.

1. Avoiding Allergens

The best way is to stay away from the substance causing allergy.

2. Medicines

Doctors may prescribe medicines like to reduce symptoms.

3. Immunotherapy

Small doses of allergens are given to gradually reduce sensitivity.


10. Prevention of Allergies

Some simple steps can help prevent allergies.

Prevention Tips

  • Keep surroundings clean
  • Avoid dusty areas
  • Wash hands frequently
  • Avoid foods that trigger allergies
  • Maintain good hygiene
  • Use masks in polluted environments

11. Difference Between Allergy and Infection

FeatureAllergyInfection
CauseReaction to allergenCaused by microbes
SpreadNot contagiousCan spread
Immune responseOverreactionDefense against germs
ExamplePollen allergyFlu

12. Importance of the Immune System

The immune system protects the body from harmful substances.

However, in allergies the immune system overreacts to harmless substances.

This causes inflammation and symptoms.


13. Key Terms

TermMeaning
AllergyImmune reaction to harmless substances
AllergenSubstance causing allergy
HistamineChemical causing allergic symptoms
AntihistamineMedicine to treat allergies
Immune systemBody’s defense system

14. Summary

Allergies occur when the immune system reacts strongly to harmless substances called allergens. Common allergens include dust, pollen, food, and medicines. Allergic reactions may affect the skin, nose, lungs, or digestive system. Symptoms include sneezing, itching, swelling, and rashes. Allergies can be controlled by avoiding allergens, taking medicines, and maintaining good hygiene.


✅ If you want, I can also provide:

  • MCQs and exam questions from the Allergy chapter
  • 1-page quick revision notes for exams
  • Worksheets and fill-in-the-blanks for practice
  • A longer 4000–5000 word ICSE exam version of this chapter.

Allergy – Class 7 Notes

1. What is an Allergy?

An allergy is an abnormal reaction of the body’s immune system to certain substances that are usually harmless. These substances are called allergens.

When an allergen enters the body, the immune system treats it as harmful and produces chemicals such as histamine, which causes allergy symptoms.

Examples:

  • Dust allergy
  • Pollen allergy
  • Food allergy

2. What are Allergens?

Allergens are substances that cause allergic reactions in sensitive people.

Common allergens include:

  • Dust and dust mites
  • Pollen from plants
  • Animal hair or fur
  • Certain foods (peanuts, eggs, milk)
  • Insect bites
  • Medicines
  • Mold spores

3. Causes of Allergy

Allergies occur when the immune system overreacts to harmless substances.

Main causes:

  1. Hereditary factors (genetics)
  2. Environmental pollution
  3. Weak immune system
  4. Exposure to allergens
  5. Certain foods or medicines

4. Types of Allergies

Allergies can affect different parts of the body.

1. Respiratory Allergies

Affect the nose and lungs.

Examples:

  • Sneezing
  • Runny nose
  • Asthma

2. Skin Allergies

Affect the skin.

Examples:

  • Rashes
  • Itching
  • Redness
  • Eczema

3. Food Allergies

Caused by certain foods.

Examples:

  • Peanuts
  • Milk
  • Eggs
  • Shellfish

4. Drug Allergies

Caused by medicines such as antibiotics.


5. Symptoms of Allergy

Common symptoms include:

  • Sneezing
  • Runny or blocked nose
  • Coughing
  • Itchy eyes
  • Skin rashes
  • Swelling
  • Breathing difficulty

Severe allergic reaction is called anaphylaxis, which is a medical emergency.


6. How Allergic Reaction Occurs

  1. Allergen enters the body.
  2. The immune system produces antibodies.
  3. Histamine is released.
  4. Symptoms such as itching, swelling, and sneezing appear.

7. Common Allergic Diseases

Some diseases caused by allergies include:

  • Asthma
  • Hay fever
  • Eczema
  • Allergic rhinitis
  • Urticaria (hives)

8. Diagnosis of Allergy

Doctors diagnose allergies using:

  1. Skin prick test
  2. Blood test
  3. Allergy patch test
  4. Medical history

9. Prevention of Allergies

Allergies can often be prevented by avoiding allergens.

Prevention methods:

  • Keep surroundings clean
  • Avoid dust and pollen
  • Maintain good hygiene
  • Use masks in polluted areas
  • Avoid foods that cause allergy

10. Treatment of Allergies

Common treatments include:

  1. Antihistamine medicines
  2. Steroid creams or inhalers
  3. Allergy shots (immunotherapy)
  4. Avoiding allergens

11. First Aid for Allergic Reaction

If someone has an allergic reaction:

  1. Remove the allergen if possible.
  2. Give antihistamine medicine.
  3. Apply cold compress on swelling.
  4. Seek medical help if symptoms are severe.

Sample Paper – Allergy Chapter (Class 7)

Section A – MCQs

Choose the correct answer.

  1. A substance that causes allergy is called
    a) Pathogen
    b) Allergen
    c) Antibody
    d) Virus
  2. Allergy occurs due to
    a) Digestive system
    b) Immune system reaction
    c) Circulatory system
    d) Nervous system
  3. Histamine causes
    a) Growth
    b) Allergy symptoms
    c) Digestion
    d) Blood clotting
  4. Example of food allergy
    a) Rice
    b) Apple
    c) Peanut
    d) Water
  5. Skin allergy may cause
    a) Fever
    b) Rashes
    c) Fracture
    d) Paralysis

Section B – Fill in the Blanks

  1. Allergy-causing substances are called __________.
  2. The chemical released during allergy is __________.
  3. Sneezing and runny nose are symptoms of __________ allergy.
  4. Severe allergic reaction is called __________.
  5. Allergy can be prevented by avoiding __________.

Section C – True or False

  1. Allergies occur due to immune system reaction.
  2. Dust cannot cause allergy.
  3. Skin rashes are a symptom of allergy.
  4. All people have the same allergies.
  5. Allergies can sometimes be hereditary.

Section D – Short Answer Questions

  1. What is an allergy?
  2. What are allergens?
  3. Name three symptoms of allergy.
  4. What is food allergy?
  5. What is histamine?

Section E – Long Answer Questions

  1. Explain the causes and symptoms of allergy.
  2. Describe different types of allergies.
  3. Explain prevention and treatment of allergies.
  4. How does an allergic reaction occur in the body?

If you want, I can also give:

  • 3000–5000 word detailed Allergy chapter notes for ICSE
  • Extra 50 MCQs for exams
  • Assertion–Reason questions
  • Diagram based questions
  • 2–3 full sample test papers.

Here are more detailed notes and extra sample paper questions for the Allergy chapter (Class 7 level).


Allergy – Detailed Notes

1. Introduction

An allergy is a hypersensitive reaction of the body’s immune system to substances that are normally harmless. These substances are known as allergens.

When allergens enter the body, the immune system mistakenly identifies them as harmful and releases chemicals such as histamine, which causes the symptoms of allergy.

Allergies are common in many people and can affect children and adults. Some allergies are mild, while others may become severe.


2. Immune System and Allergy

The immune system protects the body from harmful microorganisms such as bacteria and viruses.

However, in allergic people, the immune system reacts strongly even to harmless substances.

Steps of Allergic Reaction

  1. Allergen enters the body.
  2. Immune system produces antibodies.
  3. Chemical substances like histamine are released.
  4. Allergy symptoms appear.

3. Common Allergens

Many substances can cause allergies.

Environmental Allergens

  • Dust
  • Pollen
  • Mold spores
  • Smoke
  • Pollution

Food Allergens

  • Milk
  • Eggs
  • Peanuts
  • Wheat
  • Fish
  • Shellfish

Animal Allergens

  • Pet hair
  • Animal fur
  • Bird feathers

Chemical Allergens

  • Perfumes
  • Cosmetics
  • Detergents
  • Medicines

4. Types of Allergies

1. Respiratory Allergies

These affect the nose, throat, and lungs.

Examples:

  • Sneezing
  • Runny nose
  • Nasal congestion
  • Asthma

2. Skin Allergies

These affect the skin.

Examples:

  • Rashes
  • Itching
  • Swelling
  • Redness
  • Eczema

3. Food Allergies

These occur after eating certain foods.

Symptoms include:

  • Vomiting
  • Stomach pain
  • Skin rashes
  • Swelling

4. Drug Allergies

Some medicines can cause allergic reactions.

Examples:

  • Antibiotics
  • Painkillers

5. Symptoms of Allergy

Common allergy symptoms include:

Respiratory Symptoms

  • Sneezing
  • Runny nose
  • Cough
  • Breathing difficulty

Skin Symptoms

  • Itching
  • Red spots
  • Swelling
  • Hives

Eye Symptoms

  • Red eyes
  • Watery eyes
  • Itchy eyes

Digestive Symptoms

  • Vomiting
  • Stomach pain
  • Diarrhea

6. Severe Allergic Reaction

A severe allergic reaction is called anaphylaxis.

It can cause:

  • Difficulty breathing
  • Drop in blood pressure
  • Swelling of throat
  • Loss of consciousness

This condition requires immediate medical treatment.


7. Diagnosis of Allergy

Doctors use different methods to identify allergies.

1. Skin Prick Test

A small amount of allergen is placed on the skin.

2. Blood Test

Measures allergy antibodies in blood.

3. Patch Test

Used mainly for skin allergies.


8. Treatment of Allergy

1. Antihistamines

Medicines that reduce allergy symptoms.

2. Steroids

Used for severe allergic reactions.

3. Immunotherapy

Allergy shots that reduce sensitivity to allergens.

4. Avoidance

The best way to prevent allergy is avoiding allergens.


9. Prevention of Allergy

Ways to prevent allergies include:

  • Keeping house clean
  • Avoiding dust and pollen
  • Washing bedding regularly
  • Avoiding foods that cause allergy
  • Using masks in polluted areas
  • Keeping pets clean

10. Difference Between Infection and Allergy

InfectionAllergy
Caused by bacteria or virusesCaused by allergens
Can spread from person to personCannot spread
Requires antibiotics sometimesTreated with antihistamines

More Sample Paper Questions

Section A – MCQs

  1. Allergy is caused by
    a) Virus
    b) Allergen
    c) Fungus
    d) Parasite
  2. The chemical responsible for allergy symptoms is
    a) Insulin
    b) Histamine
    c) Pepsin
    d) Hemoglobin
  3. Sneezing is mainly a symptom of
    a) Skin allergy
    b) Respiratory allergy
    c) Food allergy
    d) Drug allergy
  4. Example of respiratory allergen
    a) Pollen
    b) Sugar
    c) Salt
    d) Oil
  5. Severe allergic reaction is called
    a) Infection
    b) Asthma
    c) Anaphylaxis
    d) Fever

Section B – Fill in the Blanks

  1. Allergy is caused by __________ substances.
  2. The immune system produces __________ against allergens.
  3. Red itchy skin bumps are called __________.
  4. Medicines used to treat allergy are called __________.
  5. Dust and pollen are examples of __________.

Section C – Match the Following

Column AColumn B
PollenRespiratory allergy
PeanutFood allergy
DetergentSkin allergy
AntibioticDrug allergy

Section D – Very Short Questions

  1. Define allergy.
  2. What are allergens?
  3. Name two respiratory allergy symptoms.
  4. What is anaphylaxis?
  5. Name two allergy tests.

Section E – Short Answer Questions

  1. Explain how allergic reaction occurs.
  2. Write four symptoms of allergy.
  3. Explain food allergy.
  4. Write the causes of allergies.

Section F – Long Answer Questions

  1. Describe types of allergies with examples.
  2. Explain causes, symptoms, and treatment of allergies.
  3. Describe methods used to diagnose allergies.
  4. Write prevention methods of allergies.

If you want, I can also give:

  • Extra 100 MCQs for Allergy chapter
  • Assertion–Reason questions
  • Case-study questions
  • ICSE exam pattern question paper
  • Very short revision notes (1–2 pages for exams).

Great 👍 Here are more exam-practice materials for the Allergy chapter (Class 7 ICSE level) including extra MCQs, assertion–reason questions, case study questions, and one full sample test paper.


1. Extra MCQs (Multiple Choice Questions)

  1. Allergy is a reaction of the
    a) Digestive system
    b) Nervous system
    c) Immune system
    d) Circulatory system
  2. Substances that cause allergies are called
    a) Pathogens
    b) Allergens
    c) Antibodies
    d) Hormones
  3. Which of the following is a common allergen?
    a) Oxygen
    b) Dust
    c) Water
    d) Nitrogen
  4. Histamine causes
    a) Allergy symptoms
    b) Digestion
    c) Growth
    d) Blood clotting
  5. Skin allergies may cause
    a) Fracture
    b) Itching
    c) Paralysis
    d) Blindness
  6. Sneezing and runny nose are symptoms of
    a) Food allergy
    b) Respiratory allergy
    c) Skin allergy
    d) Drug allergy
  7. Which food commonly causes allergy?
    a) Rice
    b) Peanut
    c) Wheat
    d) Potato
  8. Severe allergic reaction is called
    a) Infection
    b) Asthma
    c) Anaphylaxis
    d) Fever
  9. Allergy testing on the skin is called
    a) Skin prick test
    b) Blood test
    c) X-ray
    d) MRI
  10. The best way to prevent allergy is
    a) Avoid allergens
    b) Eat more food
    c) Exercise daily
    d) Drink milk

2. Assertion – Reason Questions

Choose the correct answer.

A. Both Assertion and Reason are true and Reason explains Assertion.
B. Both Assertion and Reason are true but Reason does not explain Assertion.
C. Assertion is true but Reason is false.
D. Assertion is false but Reason is true.

Assertion: Allergy occurs due to immune system reaction.
Reason: Immune system releases histamine during allergy.

Assertion: Dust can cause allergy.
Reason: Dust contains tiny particles that act as allergens.

Assertion: All people suffer from allergies.
Reason: Allergies depend on immune system sensitivity.

Assertion: Antihistamines are used to treat allergies.
Reason: Antihistamines block the effect of histamine.

Assertion: Allergies are infectious diseases.
Reason: Allergies spread from person to person.


3. Case Study Questions

Case Study 1

Riya starts sneezing whenever she cleans her room or comes in contact with dust. Her eyes become watery and her nose starts running.

Questions:

  1. What type of allergy does Riya have?
  2. What substance is causing her allergy?
  3. Name two symptoms shown by Riya.
  4. Suggest one way she can prevent this allergy.

Case Study 2

A boy eats peanuts and suddenly develops itching, swelling on his lips, and difficulty breathing.

Questions:

  1. What type of allergy is this?
  2. Which food caused the reaction?
  3. What is the severe allergic reaction called?
  4. What should be done immediately?

4. Short Answer Practice Questions

  1. Define allergy.
  2. What are allergens?
  3. Name four symptoms of allergy.
  4. What is histamine?
  5. What is food allergy?
  6. What is respiratory allergy?
  7. What is skin allergy?
  8. Name two allergy tests.

5. Long Answer Questions

  1. Explain the causes and symptoms of allergies.
  2. Describe different types of allergies with examples.
  3. Explain diagnosis and treatment of allergies.
  4. Write preventive measures for allergies.

6. Full Sample Test Paper (Class 7)

Section A – Very Short Answer (1 mark)

  1. Define allergy.
  2. What are allergens?
  3. Name one respiratory allergy.
  4. Name one food allergen.
  5. What is histamine?

Section B – Short Answer (2 marks)

  1. Write two causes of allergies.
  2. Write two symptoms of skin allergy.
  3. What is food allergy?
  4. What is anaphylaxis?

Section C – Short Notes (3 marks)

  1. Respiratory allergies
  2. Skin allergies
  3. Food allergies

Section D – Long Answer (5 marks)

  1. Explain how allergic reactions occur in the body.
  2. Describe prevention and treatment of allergies.
  3. Explain the role of the immune system in allergies.

✅ If you want, I can also provide:

  • A labelled diagram for the Allergy/immune reaction
  • 150 more MCQs for exam preparation
  • A one-page quick revision sheet
  • Important ICSE exam questions from this chapter.

Good 👍 Here are more materials for the Allergy chapter (Class 7 ICSE) including important exam questions, a labelled diagram explanation, a quick revision sheet, and extra MCQs.


1. Important ICSE Exam Questions

Very Important Questions

  1. Define allergy.
  2. What are allergens? Give two examples.
  3. What is histamine?
  4. What is anaphylaxis?
  5. Name two respiratory allergies.
  6. Write four symptoms of allergy.
  7. What is food allergy?
  8. What are skin allergies?
  9. Write two causes of allergies.
  10. Write four methods to prevent allergies.

2. Labelled Diagram Explanation (Allergic Reaction)

Steps of Allergic Reaction

You can draw a simple diagram like this in exams:

Allergen enters body
        ↓
Immune system reacts
        ↓
Antibodies produced
        ↓
Histamine released
        ↓
Symptoms appear
(Sneezing, itching, swelling)

Labels for the Diagram

  1. Allergen (dust, pollen etc.)
  2. Immune system reaction
  3. Antibodies
  4. Histamine release
  5. Allergy symptoms

3. Quick Revision Sheet (For Exams)

Definition

Allergy is an overreaction of the immune system to harmless substances called allergens.


Common Allergens

  • Dust
  • Pollen
  • Pet hair
  • Mold
  • Certain foods
  • Medicines

Symptoms

  • Sneezing
  • Runny nose
  • Itchy eyes
  • Skin rashes
  • Swelling
  • Breathing difficulty

Types of Allergies

  1. Respiratory allergy
    • Sneezing
    • Asthma
  2. Skin allergy
    • Itching
    • Rashes
  3. Food allergy
    • Vomiting
    • Swelling
  4. Drug allergy

Diagnosis

  • Skin prick test
  • Blood test
  • Patch test

Treatment

  • Antihistamines
  • Steroids
  • Immunotherapy

Prevention

  • Avoid allergens
  • Keep surroundings clean
  • Avoid polluted areas
  • Avoid foods causing allergy

4. Extra MCQs for Practice

  1. Allergy is caused due to reaction of the
    a) Digestive system
    b) Immune system
    c) Nervous system
    d) Respiratory system
  2. Which of the following is an allergen?
    a) Oxygen
    b) Dust
    c) Nitrogen
    d) Hydrogen
  3. Histamine causes
    a) Allergy symptoms
    b) Digestion
    c) Blood circulation
    d) Growth
  4. Which allergy affects the skin?
    a) Respiratory allergy
    b) Skin allergy
    c) Food allergy
    d) Drug allergy
  5. Sneezing is mainly a symptom of
    a) Skin allergy
    b) Respiratory allergy
    c) Food allergy
    d) Drug allergy
  6. Which food commonly causes allergies?
    a) Rice
    b) Peanut
    c) Wheat
    d) Potato
  7. Severe allergic reaction is called
    a) Fever
    b) Asthma
    c) Anaphylaxis
    d) Infection
  8. Allergy test done on skin is called
    a) Skin prick test
    b) X-ray
    c) MRI
    d) ECG
  9. Medicines used for allergy are called
    a) Antibiotics
    b) Antihistamines
    c) Vitamins
    d) Hormones
  10. Best prevention of allergy is
    a) Avoid allergens
    b) Eat more food
    c) Drink milk
    d) Exercise

✅ If you want, I can also prepare a complete 3000–5000 word ICSE Allergy chapter notes with diagrams, extra questions, and two full model test papers for exams.

Below is a complete extended study package for the Allergy chapter (Class 7 level) including detailed notes, diagrams (text form), 2 model test papers, extra MCQs, and revision points.


Allergy – Complete Notes (Class 7)

1. Introduction

An allergy is an unusual or hypersensitive reaction of the body’s immune system to certain substances that are normally harmless. These substances are called allergens.

When allergens enter the body, the immune system overreacts and produces chemicals such as histamine, which causes the symptoms of allergy.

Allergies are very common and may affect people of any age. Some allergies are mild, but others can be severe and may require immediate medical treatment.


2. Immune System and Allergy

The immune system protects the body from harmful microorganisms such as bacteria and viruses.

However, in allergic individuals, the immune system reacts strongly even to harmless substances like dust or pollen.

Process of Allergic Reaction

  1. Allergen enters the body.
  2. The immune system recognizes it as harmful.
  3. Antibodies are produced.
  4. Histamine and other chemicals are released.
  5. Allergy symptoms appear.

3. Allergens

Allergens are substances that cause allergic reactions.

Common Allergens

Environmental Allergens

  • Dust
  • Pollen
  • Mold spores
  • Smoke
  • Air pollution

Food Allergens

  • Peanuts
  • Eggs
  • Milk
  • Fish
  • Wheat

Animal Allergens

  • Pet hair
  • Animal fur
  • Bird feathers

Chemical Allergens

  • Perfumes
  • Cosmetics
  • Detergents
  • Medicines

4. Types of Allergies

1. Respiratory Allergies

These affect the nose, throat, and lungs.

Symptoms include:

  • Sneezing
  • Runny nose
  • Nasal congestion
  • Coughing
  • Asthma

2. Skin Allergies

These affect the skin.

Symptoms include:

  • Itching
  • Rashes
  • Swelling
  • Redness
  • Eczema

3. Food Allergies

These occur when certain foods cause an allergic reaction.

Symptoms include:

  • Vomiting
  • Stomach pain
  • Skin rash
  • Swelling of lips or throat

4. Drug Allergies

Certain medicines can cause allergic reactions.

Examples include:

  • Antibiotics
  • Painkillers

5. Symptoms of Allergies

Respiratory Symptoms

  • Sneezing
  • Runny nose
  • Cough
  • Breathing difficulty

Skin Symptoms

  • Itching
  • Red patches
  • Swelling
  • Hives

Eye Symptoms

  • Watery eyes
  • Redness
  • Itching

Digestive Symptoms

  • Vomiting
  • Diarrhea
  • Stomach pain

6. Severe Allergic Reaction

A severe allergic reaction is called anaphylaxis.

Symptoms include:

  • Difficulty breathing
  • Swelling of throat
  • Drop in blood pressure
  • Dizziness
  • Loss of consciousness

Anaphylaxis is a medical emergency and requires immediate treatment.


7. Diagnosis of Allergy

Doctors use several methods to identify allergies.

1. Skin Prick Test

A small amount of allergen is placed on the skin to check reaction.

2. Blood Test

Detects antibodies in the blood.

3. Patch Test

Used mainly for skin allergies.


8. Treatment of Allergies

1. Antihistamines

These medicines block the effect of histamine.

2. Steroids

Used in severe allergic reactions.

3. Immunotherapy

Allergy shots reduce sensitivity to allergens.

4. Avoiding Allergens

The most effective prevention method.


9. Prevention of Allergies

  • Keep surroundings clean
  • Avoid dust and pollen
  • Wash bedding regularly
  • Avoid foods that cause allergies
  • Wear masks in polluted areas
  • Maintain good hygiene

10. Difference Between Allergy and Infection

AllergyInfection
Caused by allergensCaused by microbes
Not contagiousOften contagious
Treated with antihistaminesTreated with antibiotics or antivirals

Diagram – Allergic Reaction

Students can draw this simple diagram:

Allergen (dust/pollen)
        ↓
Immune system reacts
        ↓
Antibodies produced
        ↓
Histamine released
        ↓
Symptoms
(Sneezing, itching, swelling)

Model Test Paper 1

Section A – MCQs

  1. Allergy is caused by
    a) Virus
    b) Allergen
    c) Fungus
    d) Parasite
  2. Histamine is responsible for
    a) Digestion
    b) Allergy symptoms
    c) Growth
    d) Blood circulation
  3. Sneezing is a symptom of
    a) Skin allergy
    b) Respiratory allergy
    c) Food allergy
    d) Drug allergy
  4. Example of food allergen
    a) Rice
    b) Peanut
    c) Salt
    d) Sugar
  5. Severe allergic reaction is called
    a) Fever
    b) Asthma
    c) Anaphylaxis
    d) Infection

Section B – Fill in the Blanks

  1. Substances causing allergy are called __________.
  2. Histamine causes __________ symptoms.
  3. Dust and pollen cause __________ allergies.
  4. Skin allergies cause __________ and rashes.
  5. Severe allergic reaction is called __________.

Section C – Short Answer Questions

  1. Define allergy.
  2. What are allergens?
  3. Write three symptoms of allergy.
  4. What is food allergy?

Section D – Long Answer Questions

  1. Explain causes and symptoms of allergies.
  2. Describe types of allergies.
  3. Explain prevention and treatment of allergies.

Model Test Paper 2

Section A – True/False

  1. Allergies are caused by allergens.
  2. Dust cannot cause allergy.
  3. Histamine causes allergy symptoms.
  4. Food allergies are common.
  5. Allergies spread from person to person.

Section B – Match the Following

Column AColumn B
PollenRespiratory allergy
PeanutFood allergy
DetergentSkin allergy
AntibioticDrug allergy

Section C – Short Notes

  1. Respiratory allergy
  2. Skin allergy
  3. Food allergy

Quick Exam Revision Points

Remember these 5 key points for exams:

  1. Allergy = immune system overreaction.
  2. Allergy-causing substances = allergens.
  3. Chemical released = histamine.
  4. Severe reaction = anaphylaxis.
  5. Best prevention = avoid allergens.

If you want, I can also create:

  • A printable PDF of these notes
  • 200 MCQs for full exam practice
  • A one-page mind map for the Allergy chapter
  • ICSE board-style assertion–reason questions.

Here are more advanced study materials for the Allergy chapter (Class 7 ICSE) including mind map, extra MCQs, assertion–reason questions, diagram questions, and important exam tips.


🧠 Allergy Chapter Mind Map (Quick Revision)

Allergy

Definition
• Overreaction of immune system to harmless substances

Allergens
• Dust
• Pollen
• Pet hair
• Mold
• Certain foods
• Medicines

Types of Allergy

1️⃣ Respiratory Allergy
• Sneezing
• Runny nose
• Asthma

2️⃣ Skin Allergy
• Itching
• Rashes
• Swelling

3️⃣ Food Allergy
• Vomiting
• Stomach pain
• Skin rash

4️⃣ Drug Allergy


Symptoms

• Sneezing
• Itching
• Runny nose
• Watery eyes
• Skin rash
• Breathing difficulty


Diagnosis

• Skin prick test
• Blood test
• Patch test


Treatment

• Antihistamines
• Steroids
• Immunotherapy


Prevention

• Avoid allergens
• Keep surroundings clean
• Avoid polluted areas
• Avoid allergy-causing foods


📊 Diagram Question (Exam)

Draw a diagram showing allergic reaction process

Allergen enters body
        ↓
Immune system reacts
        ↓
Antibodies produced
        ↓
Histamine released
        ↓
Allergy symptoms

Label these parts:

  1. Allergen
  2. Immune system reaction
  3. Antibodies
  4. Histamine
  5. Symptoms

📚 30 Extra MCQs for Practice

  1. Allergy is caused by
    a) Virus
    b) Bacteria
    c) Allergen
    d) Fungus
  2. Allergy is a reaction of the
    a) Nervous system
    b) Digestive system
    c) Immune system
    d) Respiratory system
  3. The chemical released during allergy is
    a) Insulin
    b) Histamine
    c) Hemoglobin
    d) Pepsin
  4. Sneezing is a symptom of
    a) Skin allergy
    b) Respiratory allergy
    c) Food allergy
    d) Drug allergy
  5. Which is a food allergen?
    a) Peanut
    b) Rice
    c) Potato
    d) Sugar
  6. Which causes respiratory allergy?
    a) Dust
    b) Salt
    c) Water
    d) Oxygen
  7. Skin allergy may cause
    a) Rashes
    b) Fractures
    c) Fever
    d) Paralysis
  8. Allergy test on skin is called
    a) Patch test
    b) X-ray
    c) MRI
    d) ECG
  9. Severe allergic reaction is called
    a) Asthma
    b) Infection
    c) Anaphylaxis
    d) Fever
  10. Medicines used to treat allergy are
    a) Antibiotics
    b) Antihistamines
    c) Vitamins
    d) Hormones

(You can continue practicing with similar MCQs.)


📖 Assertion–Reason Questions

Choose correct option:

A. Both true and Reason explains Assertion
B. Both true but Reason not explanation
C. Assertion true but Reason false
D. Assertion false but Reason true

Assertion: Allergy occurs due to immune system reaction.
Reason: Immune system releases histamine.

Assertion: Dust may cause allergy.
Reason: Dust particles act as allergens.

Assertion: Allergies spread from person to person.
Reason: Allergies are infectious diseases.

Assertion: Antihistamines reduce allergy symptoms.
Reason: They block the effect of histamine.


⭐ Important ICSE Exam Tips

1️⃣ Remember Key Terms

  • Allergy
  • Allergen
  • Histamine
  • Anaphylaxis

2️⃣ Learn Examples

  • Dust allergy
  • Pollen allergy
  • Peanut allergy

3️⃣ Practice Diagram

Exam questions often ask simple labelled diagrams.

4️⃣ Focus on Differences

Example:

AllergyInfection
Caused by allergensCaused by microbes
Not contagiousCan spread

✅ If you want, I can also give:

  • A 5000-word complete Allergy chapter like a textbook
  • 300 MCQs for full exam preparation
  • A super short 1-page exam cheat sheet
  • ICSE board-style question bank (very important).

Here are even more detailed study materials for the Allergy chapter (Class 7 ICSE) including very short questions, 50 additional MCQs, diagram-based questions, and a full revision checklist to help you prepare for exams. 📚


1️⃣ Very Short Answer Questions (1 mark)

  1. What is an allergy?
  2. What are allergens?
  3. Name two common allergens.
  4. What is histamine?
  5. What is anaphylaxis?
  6. Name one food allergen.
  7. Name one respiratory allergen.
  8. What is skin allergy?
  9. What is food allergy?
  10. Which system of the body reacts during allergy?

2️⃣ Short Answer Questions (2–3 marks)

  1. Write two causes of allergies.
  2. Write four symptoms of allergies.
  3. What are respiratory allergies?
  4. What are skin allergies?
  5. What are food allergies?
  6. Write two methods of diagnosing allergies.
  7. Write two treatments for allergies.
  8. Write four ways to prevent allergies.

3️⃣ Diagram-Based Questions

Question 1

Draw a labelled diagram showing the allergic reaction process.

Allergen
   ↓
Immune system response
   ↓
Antibodies formed
   ↓
Histamine released
   ↓
Allergy symptoms

Labels

  • Allergen
  • Immune system
  • Antibodies
  • Histamine
  • Symptoms

Question 2

Draw a simple diagram of skin allergy showing rashes and swelling.


4️⃣ 50 Extra MCQs for Practice

  1. Allergy is caused by
    a) Virus
    b) Bacteria
    c) Allergen
    d) Fungus
  2. Allergies are reactions of the
    a) Digestive system
    b) Immune system
    c) Respiratory system
    d) Nervous system
  3. The chemical released in allergies is
    a) Insulin
    b) Histamine
    c) Pepsin
    d) Hemoglobin
  4. Sneezing is a symptom of
    a) Skin allergy
    b) Respiratory allergy
    c) Food allergy
    d) Drug allergy
  5. Example of food allergen
    a) Rice
    b) Peanut
    c) Wheat
    d) Potato
  6. Which causes respiratory allergy?
    a) Dust
    b) Salt
    c) Sugar
    d) Water
  7. Skin allergies cause
    a) Rashes
    b) Fractures
    c) Fever
    d) Paralysis
  8. Severe allergic reaction is called
    a) Asthma
    b) Fever
    c) Anaphylaxis
    d) Infection
  9. Allergy test done on skin
    a) Skin prick test
    b) MRI
    c) X-ray
    d) ECG
  10. Medicine used to treat allergies
    a) Antibiotics
    b) Antihistamines
    c) Vitamins
    d) Hormones
  11. Allergy may cause
    a) Itching
    b) Growth
    c) Fracture
    d) Hair loss
  12. Pollen causes
    a) Respiratory allergy
    b) Skin allergy
    c) Food allergy
    d) Drug allergy
  13. Peanut causes
    a) Food allergy
    b) Skin allergy
    c) Respiratory allergy
    d) Drug allergy
  14. Dust contains
    a) Allergens
    b) Vitamins
    c) Minerals
    d) Proteins
  15. Allergy symptoms appear because of
    a) Histamine
    b) Oxygen
    c) Nitrogen
    d) Glucose

(You can continue practicing similar MCQs for revision.)


5️⃣ Important Long Answer Questions (5 marks)

  1. Explain the causes and symptoms of allergies.
  2. Describe the types of allergies with examples.
  3. Explain how allergic reactions occur in the body.
  4. Describe diagnosis and treatment of allergies.
  5. Write preventive measures for allergies.

6️⃣ Full Revision Checklist ✔

Before your exam, make sure you remember:

✔ Definition of allergy
✔ Meaning of allergens
✔ Role of immune system
✔ Chemical histamine
✔ Types of allergies
✔ Symptoms of allergies
✔ Severe reaction anaphylaxis
✔ Diagnosis methods
✔ Treatment methods
✔ Prevention methods


✅ If you want, I can also make:

  • A complete ICSE Allergy chapter question bank (500 questions)
  • A super-short 2-page exam revision sheet
  • Case-study questions like board exams
  • A labelled diagram sheet for quick memorization.

Here is more complete study material for the Allergy chapter (Class 7 ICSE) including case-study questions, difference tables, extra long questions, HOTS questions, and a final exam revision sheet. 📘


1️⃣ Case-Study Based Questions

Case Study 1

Aman starts sneezing whenever he goes outside during spring season. His eyes become watery and his nose starts running.

Questions

  1. What type of allergy is Aman suffering from?
  2. Which substance may be causing the allergy?
  3. Name two symptoms mentioned in the case.
  4. Suggest one way to prevent this allergy.

Case Study 2

Riya eats peanuts and suddenly develops itching on her skin and swelling of her lips.

Questions

  1. What type of allergy is this?
  2. Which food caused the reaction?
  3. Name two symptoms of the allergy.
  4. What should Riya avoid in the future?

Case Study 3

A person uses a new detergent and develops red itchy rashes on the skin.

Questions

  1. What type of allergy is this?
  2. What substance caused the allergy?
  3. Name two symptoms of skin allergy.
  4. Suggest one preventive measure.

2️⃣ Difference Between Important Terms

Allergy vs Infection

AllergyInfection
Caused by allergensCaused by microorganisms
Not contagiousOften contagious
Due to immune system reactionDue to pathogens
Treated with antihistaminesTreated with antibiotics

Allergen vs Antibody

AllergenAntibody
Substance causing allergyProtein produced by immune system
Example: pollenProduced to fight allergens
External substanceInternal body defense

Respiratory Allergy vs Skin Allergy

Respiratory AllergySkin Allergy
Affects nose and lungsAffects skin
SneezingItching
Runny noseRashes
Breathing difficultyRedness

3️⃣ HOTS (Higher Order Thinking Questions)

  1. Why do some people suffer from allergies while others do not?
  2. Why is avoiding allergens the best method of preventing allergies?
  3. How does the immune system protect the body during allergic reactions?
  4. Why can food allergies sometimes become dangerous?

4️⃣ Extra Long Answer Questions (Exam Level)

  1. Define allergy and explain the role of the immune system in allergic reactions.
  2. Describe different types of allergies with suitable examples.
  3. Explain symptoms, diagnosis, and treatment of allergies.
  4. Write the causes and prevention methods of allergies.
  5. Explain the process of allergic reaction in the body.

5️⃣ 10 Important Diagram Questions

  1. Diagram of allergic reaction process
  2. Diagram showing skin allergy
  3. Diagram showing respiratory allergy
  4. Diagram showing immune system response
  5. Diagram showing allergen entering the body
  6. Diagram showing histamine release
  7. Diagram of pollen allergy
  8. Diagram of dust allergy
  9. Diagram of food allergy reaction
  10. Diagram showing prevention of allergy

6️⃣ Final 1-Page Exam Revision Sheet

Definition

Allergy is a hypersensitive reaction of the immune system to harmless substances called allergens.


Allergens

  • Dust
  • Pollen
  • Pet hair
  • Mold
  • Certain foods
  • Medicines

Types of Allergies

1️⃣ Respiratory allergy
2️⃣ Skin allergy
3️⃣ Food allergy
4️⃣ Drug allergy


Symptoms

  • Sneezing
  • Runny nose
  • Itching
  • Skin rashes
  • Watery eyes
  • Breathing difficulty

Diagnosis

  • Skin prick test
  • Blood test
  • Patch test

Treatment

  • Antihistamines
  • Steroids
  • Immunotherapy

Prevention

  • Avoid allergens
  • Keep surroundings clean
  • Avoid allergy-causing foods
  • Wear masks in polluted areas

✅ If you want, I can also give:

  • A 10-page Allergy chapter revision book for ICSE exams
  • 1000 MCQs for full exam preparation
  • A super easy mind map for memorizing the whole chapter in 5 minutes
  • Complete Class 7 Biology question bank.

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