anaphylaxis Flashcards
what is a hypersensitivity reaction?
what is anaphylaxis?
what is the pathophysiology of anaphylaxis?
is an inappropriate immune response to generally harmless antigens,
Anaphylaxis
represents the most dramatic and severe form of immediate hypersensitivity
any agent capable of producing a sudden degranulation of mast cells or
basophils can induce anaphylaxis
2 arises from activation of mast cells and basophills throgh a mechanism involving ige and ige mediated receptors
what are the chemicals released from activation of basophils and mast cells ?
histamine ,tryptase carboxypeptidaseA and proteoglycans …down stream activation of phospholipase A2, followed by
cyclooxygenases and lipoxygenases, produces arachidonic acid metabolites,including prostaglandins, leukotrienes, and platelet-activating factor.
what are the classic presentations of anaphylaxis ??
pruritus, cutaneous flushing, and urticaria followed by a sense of fullness in the throat, anxiety, a sensation of chest tightness, shortness of breath, and lightheadedness.
These major symptoms may be accompanied
by abdominal pain or cramping, nausea, vomiting, diarrhea, bronchospasm, rhinorrhea, conjunctivitis, and/or hypotension.
when does anaphylaxis starts to occur after exposure
signs and symptoms begin suddenly, often immediately and usually within 60 minutes of exposure.50% of anaphylactic fatalities occur within the 1st hour.
recurrence of symptoms caused by a second phase of mediator release, peaking 8 to 11 hours after the initial exposure and manifesting symptoms and signs 3 to 4 hours after the initial clinical manifestations have cleared mediated by cysteinyl leukotrienese.
diagnosis of anaphylaxis ?
what are the limitations of measuring serum histamine and tryptase level ?
when involvement of any two or more body systems is observed, with or without hypotension or airway compromise.
serum histamine elevated only for 5 to 30 minutes
tryptase have low sensetivity
what are treatment steps ?
what are the second line therapies?
ABC,epinephrine,iv crystalloids
2 corticosteroids, antihistamines, inhaled bronchodilators, vasopressors, and glucagon
what are the disposition plans of patients with anaphylaxis ?
and who needs prolonged observation
what are the discharge medications and instructions that should be given before discharge ?
2 patients with prior history and patients an beta blockers
3 anti histamine and corticsteroids for 3-5 days
may be prologed for 1-2 weeks for idiopathic anaphylaxis patients
prescribe an epinephrine autoinjector
MedicAlert® bracelets
what is urticaria or hives and what are the treatments ?
cutaneous reaction marked by acute onset of pruritic, erythemic wheals of varying size that generally are described as “fleeting.”
treatment is generaly supportive
what is angioedema
2 what is the management of ACE inhibitor-induced angioedema?
3 what are the effective agents
deeper involvement characterized by edema formation in the dermis, generally involving the face and neck and distal extremities.
ACE inhibitor is a common trigger occurring in 0.1-0.7% of patients
2pathophysiology is complex, involving both bradykinin and substance P
management is supportive, with special attention to the airway, which can become occluded rapidly and unpredictably.
epinephrine, antihistamines, and corticosteroids, are not benefecial because it is not mediated by ige
3 icatibant and c1 esterase inhibitor
what is hereditary angioedema?
2 managment options ?
rare autosomal dominant disorder due to deficiency in C1 esterase inhibitor, either low levels (type I) or a dysfunctional enzyme (type II).
characterized by acute edematous reactions involving the upper respiratory system, soft tissue of extremities or trunk, or gastrointestinal tract.
A C4 level <30% of normal suggests the diagnosis
2 C1 esterase inhibitor the bradykinin-2 receptor antagonist icatibant, or the kallikrein inhibitor ecallantide ,FFP
Prophylaxis with attenuated androgens, such as stanozolol 2 milligrams PO TID or danazol 200 milligrams PO TID.
