allergy Flashcards
what is the definition of allergy?
hypersensitive disorder of the immune system
what is the name for substances that trigger allergies?
allergens
what is an allergic reaction?
an exaggerated or inappropriate immune response to an allergen which causes damage to the host
what is the pathophysiology of an allergic reaction?
IgE mediated triggering of mast cells and subsequemt accumulation of inflammatory cells at sites of antigen deposition
what are some of the products that are released during degranulation of mast cells?
histamine cytokines interleukins leukotrines prostaglandins
what are some systemic effects of allergic reactions?
vasodilation
mucous secretion
nerve stimulation
smooth muscle contraction
how long after the initial reaction does the late phase response take effect?
2-4 hours
what kinds of leukocytes are involved in the late phase response?
neutrophils
lymphocytes
eosinophils
macrophages
what are some host risk factors for allergy?
heredity
race
age
what are some environmental risk factors for allergy?
exposure to infectious diseases in childhood
environmental pollution
allergen levels
dietary changes
how is allergy diagnosed?
skin test - response to known allergens
RAST - presence and levels of allergen specific IgE
what are some treatment modalities for allergies?
avoidance of allergens
pharmacotherapy
immunotherapy
what are some different classes of drugs used to treat allergic reactions?
antihistamines
glucocorticoids
epinephrine
theophylline
what is immunotherapy?
controlled exposure to known allergens to reduce the severity of allergy
what is allergic rhinitis?
allergic inflammation of the nasal airways
