Allergy

Question 1

Types of hypersensitivity reactions:

Answer 1

Type-I: IgE immediate
Type-II: IgM,IgG antibody dependent
Type-III: Immune complex
Type-IV: T-cell mediated

Question 2

Type-I: Immediate Anaphylactic reaction

Answer 2

IgE
Symp: hives, rash, wheezing, red man syndrome

Mediators: Histamine, Serotonin, Bradykinin, prostaglandins, Leukotrienes

Question 3

Type-II: Cytotoxic reaction, Ab dependent

Answer 3

IgG, IgM
Ab reacting with Ag (either intrinsic or extrinsic) to induce cell lysis

Example:
Rh incompatibility,
incompatible blood donor &
autoimmune diseases (hemolytic anemia)

Question 4

Type-III: Immune complex

Answer 4

1-3 weeks

Formation Ag-Ab complex leading to tissue damage

Example: SLE, Leprosy

Question 5

Type-IV: Cell mediated (delayed)

Answer 5

T-lymphocyte and macrophages

Produces cytokines affecting function of cells

Example: SJS,TB