department of athletics policies & procedures - UNC Wilmington ...

Definition of Anaphylaxis:
Anaphylaxis is a systemic, immediate hypersensitivity reaction caused by
immunoglobulin (Ig) E-dependent activation of effector cells of the immune system,
predominantly mast cells and basophils. It can be triggered by exposure to various
antigens from foods, drugs, or insect stings, and also by latex, exercise, or other
diagnostic agents. Mediators elaborated by these effector cells are responsible for the
symptoms of anaphylaxis, which may involve the cutaneous, respiratory, gastrointestinal,
or cardiovascular systems. Anaphylactoid reactions are clinically similar to anaphylactic
reactions but are not mediated by IgE-dependent activation. Thus, regardless of triggering
cause, anaphylactic or anaphylactoid reactions occur as a consequence of inappropriate
and overwhelming mast cell or basophil activation.
Common Signs/Symptoms of Anaphylaxis:
After exposure to an antigenic trigger, symptoms generally develop within 5 to 30
minutes, although, less commonly, symptoms can occur up to several hours after the
exposure (see table below). Five percent to 20% of patients who suffer an initial
anaphylactic event can experience biphasic anaphylaxis, in which symptoms recur up to 8
hours after the initial event, presumably due to a late-phase reaction triggered by the
recruitment of inflammatory cells after the initial hypersensitivity response. Up to 6% of
patients with anaphylaxis may experience biphasic symptoms. Protracted anaphylaxis
occurs at a rate of less than 1% in patients who experience persistent symptoms for up to
48 hours after initial exposure. Biphasic or protracted anaphylaxis occurs more
commonly in patients who develop delayed symptoms upon antigen exposure or who
received the antigen by the oral route (PO).
Organ
Common Organ Symptoms
Skin
Respiratory
Urticaria and angioedema, flushing,
pruritis
Dyspnea, wheezing, airway
angioedema, rhinitis
Nausea, vomiting, diarrhea, cramping,
Gastrointestinal
pain
Cardiovascular
Neurologic
Tachycardia, hypotension, cardiac
arrest, chest pain
Headache, dizziness, seizures, "sense
of impending doom"
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