In: Biology
clinical signs of each types of hypersensitivity
Soln- There are four types of hypersensitivity.
1. IgE mediated Type I hypersensitivity- this hypersensitive reaction is induced by certain types of antigens called allergens. The clinical signs are systemic anaphylaxis and localized anaphylaxis such as hay fever, asthma, hives, food allergies and eczema.
2. Antibody mediated Cytotoxic Type II hypersensitivity- involves antibody mediated destruction of cells. The clinical signs are blood transfusion reactions, erythroblastosis fetalis, and autoimmune hemolytic anaemia.
3. Immune complex mediated Type III hypersensitivity- The reaction of antibody with antigen generates immune complexes. The clinical signs are localized Arthur's reaction and generalized reactions such as serum sickness, necrotizing vasculitis, rheumatoid arthritis and systemic lupus erythematosus.
4. Cell mediated Type IV hypersensitivity- it develops when antigen activates sensitized Tdth cells that releases cytokines resulting in macrophage activation mediating direct cellular damage. The clinical signs are contact dermititis, tubercular lesions and graft rejection.