Hypersensitivities Flashcards
2 subgroups of Type 1
Atopy
Anaphylaxis
Type I mediated by?
IgE…
Immediate reactions
Urticaria and angioedema
Hives and facial/neck swelling
Usually acute
Only 10% angiogram alone (ace inhibitors)
Urticaria and angioedema management
Avoidance
Avoidance of ASA, NSAIDS, ETOH , ACE inhibitors
Anaphylaxis vs. anaphylactoid
Phylaxis is IgE mediated and phylactoid is not, but presentation and treatment are identical
Examples of type I
Anaphylaxis, urticaria, angioedema, bronchospasm, allergic rhinitis, drug allergies
Type II mediated by
Antibody dependent cytotoxicity
IgG or IgM is made against normal self antigens OR foreign antigen resembles host cell, and antibodies begin to act on host
Examples of type II
AB and Rh blood group reactions ITP (platelet destruction) Hashimoto's thyroiditis Grave's disease Myasthenia Gravis (antibodies bind to muscle) Goodpasture's syndrome (antibodies against oligodendrocytes) Some drug rxns Hemolytic anemia Interstitial nephritie
Febrile non-hemolytic transfusion rxn
Most common, fever and dyspnea
Clinically benign
Type III hypersensitivity
Antigen-antibody complexes form and circulate, deposited in vessel walls or small spaces causing inflammation, neutrophils and monocytes recruited and cause tissue damage
Favorite sites of Type III
Glomeruli, joints, ski , heart, serosal surfaces, small blood vessels
Examples of Type III
Serum sickness
Glomerulonephritis
Rheumatoid arthritis
SLE (lupus)
Type IV is mediated by…
Antigen activated T cells
2 different types of Type IV hypersensitivity
Type 1: CD4 secrete cytokines which recruit leukocytes to stimulate phagocytosis
Type 2: CD8 directly kills tissues
Examples of Type IV
Contact dermatitis
Temporal Arthritis
Celiac sprue
