Hypersensitivity: Summary Type I Hypersensitivity: • Immunological Mediator: lgE • Immunological Target: Allergen Molecules • Ex: Antibiotic allergies (ex. penicillin & cephalosporin), Food allergies (ex. peanuts), Hay fever, Urticaria, Allergic conjunctivitis Type II Hypersensitivity: • Immunological Mediator: IgM + IgG • Immunological Target: Modified cell surfaces • Ex: Autoimmune thrombocytic purpura, Heparin induced thrombocytopenia, Autoimmune Hemolytic anemia, Penicillin-induced drug reaction, Myasthenia Gravis, Graves' Disease Type III Hypersensitivity: • Immunological Mediator: IgG • Immunological Target: Antigen-Ab immune complexes • Ex: Systemic Lupus Erythematosus, Reactive Arthritis, Post-infectious glomerulonephritis, Serum sickness Type IV Hypersensitivity: • Immunological Mediator: Th Cells • Immunological Target: Allergen molecules • Ex: Stevens-Johnson Syndrome, Contact Dermatitis (ie. reaction to poison ivy) #Hypersensitivity #Allergy #Allergic #Reactions #Types #Classification #Diagnosis #Definitions
