MCQs on “Allergic Reactions: Mechanisms and Treatments”

1. What is the primary immune cell involved in an allergic reaction?
   a) Neutrophils
   b) Eosinophils
   c) Mast cells
   d) T lymphocytesAnswer: c) Mast cells

2. Which antibody is primarily responsible for triggering allergic reactions?
   a) IgA
   b) IgM
   c) IgG
   d) IgEAnswer: d) IgE

3. Which of the following is a common symptom of an allergic reaction?
   a) Fever
   b) Sneezing
   c) Coughing
   d) VomitingAnswer: b) Sneezing

4. Which type of hypersensitivity is associated with allergic reactions?
   a) Type I
   b) Type II
   c) Type III
   d) Type IVAnswer: a) Type I

5. What does histamine do during an allergic reaction?
   a) Increases heart rate
   b) Causes blood vessel dilation
   c) Reduces inflammation
   d) Decreases mucus productionAnswer: b) Causes blood vessel dilation

6. What is the main treatment for severe allergic reactions such as anaphylaxis?
   a) Antihistamines
   b) Epinephrine
   c) Steroids
   d) AntibioticsAnswer: b) Epinephrine

7. Which of the following is NOT a common trigger for allergic reactions?
   a) Pollen
   b) Dust mites
   c) Cold weather
   d) Food allergensAnswer: c) Cold weather

8. Which of the following medications is used to block the action of histamine in allergic reactions?
   a) Antihistamines
   b) Beta-blockers
   c) NSAIDs
   d) AntibioticsAnswer: a) Antihistamines

9. What is the condition known as when the body has an allergic reaction to food?
   a) Asthma
   b) Hay fever
   c) Food allergy
   d) EczemaAnswer: c) Food allergy

10. In which organ does the IgE-mediated allergic reaction primarily occur during an asthma attack?
    a) Skin
    b) Lungs
    c) Heart
    d) StomachAnswer: b) Lungs

11. Which of the following is a common treatment for allergic rhinitis?
    a) Insulin
    b) Antihistamines
    c) Antibiotics
    d) Antiviral drugsAnswer: b) Antihistamines

12. Anaphylaxis is most commonly caused by which of the following?
    a) Bee stings
    b) Cold air
    c) Sunlight exposure
    d) Physical exerciseAnswer: a) Bee stings

13. Which of the following is a characteristic of a Type I hypersensitivity reaction?
    a) Delayed response
    b) Immediate response
    c) Tissue necrosis
    d) Tissue destructionAnswer: b) Immediate response

14. Which of the following is NOT a symptom of anaphylaxis?
    a) Difficulty breathing
    b) Swelling of the throat
    c) Skin rash
    d) Excessive thirstAnswer: d) Excessive thirst

15. What is the role of mast cells in allergic reactions?
    a) Secrete histamine
    b) Release toxins
    c) Produce antibodies
    d) Destroy pathogensAnswer: a) Secrete histamine

16. Which of the following allergens commonly causes allergic rhinitis?
    a) Cat dander
    b) Bee venom
    c) Milk
    d) WheatAnswer: a) Cat dander

17. Which of the following treatments can help prevent allergic reactions in the long term?
    a) Immunotherapy
    b) Steroids
    c) Antihistamines
    d) Antiviral drugsAnswer: a) Immunotherapy

18. Which of the following is an example of a Type II hypersensitivity reaction?
    a) Hay fever
    b) Rheumatic fever
    c) Blood transfusion reactions
    d) AsthmaAnswer: c) Blood transfusion reactions

19. What is the primary function of IgE antibodies in allergic reactions?
    a) Promote inflammation
    b) Bind to allergens
    c) Facilitate phagocytosis
    d) Neutralize toxinsAnswer: b) Bind to allergens

20. Which of the following is a common treatment option for allergic skin reactions like hives?
    a) Antihistamines
    b) Antibiotics
    c) Antipyretics
    d) CorticosteroidsAnswer: a) Antihistamines

21. What can trigger an asthma attack in individuals with asthma allergies?
    a) Exercise
    b) Dust mites
    c) Pollen
    d) All of the aboveAnswer: d) All of the above

22. Which of the following is a common food allergen?
    a) Bananas
    b) Peanuts
    c) Apples
    d) CarrotsAnswer: b) Peanuts

23. What is the mechanism of action of corticosteroids in allergic reactions?
    a) They block histamine release
    b) They suppress inflammation
    c) They promote the production of IgE
    d) They reduce the production of eosinophilsAnswer: b) They suppress inflammation

24. Which of the following allergic reactions is commonly triggered by exposure to pollen?
    a) Asthma
    b) Hay fever
    c) Eczema
    d) AnaphylaxisAnswer: b) Hay fever

25. Which of the following is a potential complication of untreated severe allergic reactions?
    a) Chronic fatigue syndrome
    b) Organ failure
    c) Autoimmune disease
    d) Nervous system damageAnswer: b) Organ failure

26. What is the immediate response in the body during an allergic reaction?
    a) Immune system activation
    b) Mast cell degranulation
    c) Increased white blood cell count
    d) Antibody productionAnswer: b) Mast cell degranulation

27. Which type of allergy is most commonly associated with hives (urticaria)?
    a) Food allergies
    b) Drug allergies
    c) Insect sting allergies
    d) Pollen allergiesAnswer: a) Food allergies

28. Which of the following is a treatment option for patients with severe allergic asthma?
    a) Oral antibiotics
    b) Inhaled corticosteroids
    c) Antiviral medications
    d) Topical antifungalsAnswer: b) Inhaled corticosteroids

29. Which of the following can be a result of repeated exposure to allergens without proper treatment?
    a) Asthma attacks
    b) Tolerance
    c) Autoimmune response
    d) Chronic infectionsAnswer: a) Asthma attacks

30. Which of the following is NOT considered a preventive measure for allergic reactions?
    a) Allergen avoidance
    b) Use of antihistamines
    c) Immunotherapy
    d) Sun exposureAnswer: d) Sun exposure

These questions and answers provide a comprehensive overview of allergic reactions, their mechanisms, and available treatments.