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Health and Hygiene - Symptoms of Allergies

Grade 7ICSE

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

An allergy is an exaggerated or hypersensitive immune response to substances that are generally harmless to most people, known as allergens.

The chemical substance released by mast cells during an allergic reaction is Histamine (C5H9N3C_5H_9N_3), which is responsible for the symptoms.

Common respiratory symptoms include sneezing, running nose (rhinitis), and coughing due to the inflammation of the mucous membranes.

Skin-related symptoms include Urticaria (hives), which are red, itchy welts, and Eczema (atopic dermatitis) characterized by dry, itchy skin.

Gastrointestinal symptoms of food allergies may include nausea, vomiting, abdominal pain, and diarrhea.

Anaphylaxis is a severe, life-threatening systemic reaction characterized by a sudden drop in blood pressure and difficulty in breathing.

The immune system produces a specific type of antibody called Immunoglobulin E (IgEIgE) to fight against allergens.

📐Formulae

Allergen+IgEMast Cell ActivationHistamine Release\text{Allergen} + IgE \rightarrow \text{Mast Cell Activation} \rightarrow \text{Histamine Release}

Chemical formula of Histamine:C5H9N3\text{Chemical formula of Histamine}: C_5H_9N_3

💡Examples

Problem 1:

A child consumes peanuts and immediately develops swelling of the lips (Angioedema) and difficulty breathing. Identify the type of reaction and the primary chemical involved.

Solution:

This is a severe allergic reaction (potentially Anaphylaxis). The primary chemical involved is Histamine (C5H9N3C_5H_9N_3).

Explanation:

Peanut proteins act as allergens, triggering IgEIgE antibodies to release massive amounts of Histamine, leading to rapid tissue swelling and constriction of airways.

Problem 2:

During the spring season, a student suffers from repeated sneezing and watery eyes. What is this condition called in medical terms?

Solution:

The condition is called Allergic Rhinitis, commonly known as Hay Fever.

Explanation:

Pollen grains enter the nasal passage, causing inflammation and fluid secretion as part of the body's hypersensitive defense mechanism.