SIGNS & SYMPTOMS
What skin manifestation is commonly associated with anaphylaxis?
Urticaria (hives), often accompanied by itching and flushing.
Which immune cells release histamine during anaphylaxis?
Mast cells and basophils.
What is the first-line medication for anaphylaxis?
Intramuscular epinephrine.
What respiratory sound may occur when anaphylaxis causes lower airway bronchoconstriction?
Wheezing.
What happens to systemic vascular resistance during anaphylactic shock?
It decreases due to widespread vasodilation.
Which receptors does epinephrine stimulate to reverse bronchoconstriction and increase vascular resistance?
Beta-2 receptors cause bronchodilation, while alpha-1 receptors cause vasoconstriction.
A patient experiencing anaphylaxis presents with inspiratory stridor, hoarseness, and difficulty swallowing. What life-threatening complication do these findings indicate?
Upper airway edema (particularly laryngeal edema), which can rapidly progress to complete airway obstruction.
What two vascular changes contribute to hypotension during anaphylactic shock?
Systemic vasodilation and increased capillary permeability, which causes fluid to shift into the interstitial space.
What is the preferred route and anatomical location for administering epinephrine to a patient experiencing anaphylactic shock?
Intramuscular (IM) injection into the vastus lateralis muscle, located on the anterolateral (outer middle) thigh.