Anaphylaxis Flashcards
potentially life-threatening systemic allergic reaction involving one or more organ systems that typically occurs within seconds to minutes of exposure to the anaphylactic trigger, most often a drug, food, or hymenoptera sting.
Anaphylaxis
While 80–90% of anaphylactic episodes are uniphasic, about 10–20% of cases are biphasic in which anaphylactic symptoms return about an hour or longer after resolution of initial symptoms
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microscopic findings in the bronchi, however, are
limited to luminal secretions, peribronchial congestion, submucosal edema, and eosinophilic infiltration, and the acute emphysema is attributed to intractable bronchospasm that subsides with death.
Findings due to death
the acute emphysema is attributed to intractable bronchospasm that subsides with death.
Angioedema
microscopic examination, there is wide separation of the collagen fibers and the glandular elements; vascular congestion and eosinophilic infiltration
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Gastrointestinal manifestations represent another severe presentation of anaphylaxis, and include nausea, vomiting, crampy abdominal pain, and/or fecal incontinence. Angioedema of the bowel wall may also cause sufficient intravascular volume depletion to precipitate cardiovascular collapse.
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Cutaneous manifestations are among the most common presentations of anaphylaxis
(>90% of cases).
Atopy is not generally thought to be a risk factor for anaphylaxis from drug reactions or hymenoptera stings,
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signal transduction events leading to hypersensitivity syndromes including anaphylaxis.
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IgE-mediated drug allergies are most common with——- and certain chemotherapy drugs,
antibiotics
case of allergy to carboplatin, the incidence of hypersensitivity is 27% in patients who have had ≥7 lifetime infusions and as high as 46% in patients who have had ≥15 lifetime infusions.
27%, 7
46% 15 infusions
derived from a mouse cell line expressing a transferase that tags the Fab’ portion of the ———heavy chain with alpha-gal.
Cetuximab
patients with a history of multiple bites from Amblyomma americanum ticks commonly found in the Carolinas, Arkansas, and Tennessee are more likely to have anti-alpha-gal IgE
Amblyomma americanum has
In a process known as ————
Mast cells and basophils c tain preformed granules comprised of histamine, proteases (tryptase, chymase), proteoglycans (heparin, chondroitin sulfate), and TNF-α, which are rapidly released into surrounding tissue upon cell activation, a process known as degranulation.
Cysteinyl leukotrienes and prostaglandin D 2 cause bronchoconstriction and increased microvascular permeability.
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——— levels correlate with anaphylaxis severity and are inversely proportional to the constitutive level of PAF acetylhydrolase, which is necessary for PAF inactivation
SERUM PAF
This dorectly activates the complement c cade, resulting in complement-dependent induced histamine release from mast cells and basophils.
Cremophor oil of paclitaxel
exception is delayed anaphylaxis to meats in alpha-gal sensitized patients
MEAT
The most obvious serum biomarker to assay, histamine, has an extremely short half-life with a measurable time-window that expires <1 h from the onset of anaphylaxis
Histamine
peaks 60–90 min after the onset of anaphylaxis and can be m sured as long as 5 h after the onset of anaphylaxis
Serum tryptase
treatment of first choice is intramuscular a tration of 0.3–0.5 mL of 1:1000 (1 mg/mL) epinephrine, with repeated doses at 5–20 min intervals as needed for a severe reaction.
IM EPI
The failure to use epinephrine within the first 20 min of symptoms is a risk factor for poor clinical outcomes in various studies of anaphylaxis.
20min
Another important variable that may affect anaphylaxis survival is body posture, as an upright or sitting posture may lead to the “empty heart syndrome” in which there is insufficient venous return to the heart from sudden onset hypotension secondary to intravascular volume depletion.
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For this reason, it is recommended that patients who suffer from anaphylaxis be placed in the supine position before receiving epinephrine.
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In the case of hymenoptera allergy, patients receive VIT extracts containing actual hymenoptera venom with a maintenance dose equivalent to 2–5 stings.
VIR of 2-5 atongs in 3-5 years
tendency to manifest asthma, rhinitis, u caria, and atopic dermatitis alone or in combination, in association with the presence of allergen-specific IgE
Atopy
key effector cells in allergic rhinitis and asthma, and the dominant effector in urticaria, anaphylaxis, and systemic mastocytosis, its developmental biology, activation pathway, product profile, and target tissues will be considered in the introduction to these clinical disorders
Key effector cells
binding of IgE to human mast cells and basophils, a process termed
sensitization,
