Question

A girl develops sneezing, watery eyes and difficulty in breathing every time she visits a flower garden.
Identify the condition.
Name the immune component responsible for this condition.
(iii) Name the chemical released.
(iv) State one medicine used to treat such a condition.

Hint:

Think of the cascade as a linear path: Allergen (Pollen) $\rightarrow$ $\text{IgE}$ Antibody $\rightarrow$ Mast Cell Degranulation $\rightarrow$ Histamine Release $\rightarrow$ Antihistamine Blocker. Keeping this sequence in mind covers all parts of this question.

Answer 1

Step 1: Understanding the Question:
The question presents a scenario where a girl consistently develops acute respiratory and ocular symptoms (sneezing, runny eyes, dyspnea) when exposed to a specific outdoor environment (a flower garden). We must identify this physiological condition and its underlying immunological components, signaling molecules, and pharmaceutical treatments.

Step 2: Key Formula or Approach:
An exaggerated hypersensitivity reaction of the immune system to normally harmless environmental substances (allergens like plant pollen) is defined as an allergy. This reaction is mediated by specific immunoglobulins and tissue mast cells.

Step 3: Detailed Explanation:
(i) Identification of the Condition: The acute physical symptoms triggered by pollen grains in the garden indicate an Allergy (Allergic Rhinitis Hay Fever).
(ii) Immune Component Responsible: The specific class of antibodies produced by the immune system in response to allergens is $\text{IgE$ antibodies} (Immunoglobulin E).
(iii) Chemical Released: When allergens cross-link the $\text{IgE}$ molecules bound to tissue mast cells, it causes degranulation and the rapid release of inflammatory chemicals, primarily Histamine and Serotonin.
(iv) Medicine Used for Treatment: To counteract these symptoms, patients are treated with Antihistamines (e.g., Cetirizine), or other emergency medications like adrenaline or steroids.

Step 4: Final Answer:
(i) The condition is an Allergy. (ii) The immune component is $\text{IgE$ antibody}. (iii) The chemical released is Histamine. (iv) The medicine used for treatment is an Antihistamine.