Term
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Definition
urticaria: mediated by cutaneous mast cells in superficial dermis
angioedema: bast cells deeper in dermis and scubcut tissues; extravasation of fluid into interstitial tissues |
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Term
| acute v chronic urticaria |
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Definition
acute: new onset, present less than 6 weeks
chronic: recurrent, present > 6 weeks |
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Term
| urticaria characteristics |
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Definition
raised, well circumscribed, erythematous
pruritic
blanch w/pressure
fleeting: appear over minutes, enlarge and coalesce w/other lesions, disappear over a few hours, do not leave residual marks/scars
can occur anywhere on the body |
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Term
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Definition
due to rapid changes in temperature
erythematous papule-like hives
burning sensation |
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Term
raised streaks where skin has been scratched or stroked
usually lasts 1/2 hour |
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Definition
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Term
| angioedema characteristics |
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Definition
localized deep swelling/edema of skin or mucosal tissues
no discoloratin of skin
asymmetric
primarily affects face, mouth, kips, throat, larynx, genitals, bowels
onset in minutes to hours
may have burning sensation
often accompanied by urticaria and/or a component of anaphylaxis |
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Term
| Pathogenesis of urticaria and angioedema |
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Definition
IgE mediated
non-IgE mediated: direct mast cell activation, complement mediated, autoimmune |
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Term
| What is the most common medication that causes IgE mediated urticaria? |
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Definition
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Term
| What is the most common food causing urticaria in children and adults? |
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Definition
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Term
| What is the most common cause of acute urticaria in kids? |
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Definition
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Term
| What is responsible for the angioedema caused by ACE-inhibitors? |
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Definition
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Term
| How is urticaria treated? |
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Definition
usually self-limited/resolves spontaneously
H1 antihistamines: improve symptoms and QOL (2nd gen = DOC)
Adding H2 antag may be more effective
corticosteroids do not inhibit mast cell degran but can reduce itching via supressing inflamm mechanism |
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Term
| What are symptoms of anaphylaxis |
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Definition
pruritis
airway edema
bronchospasm
vascular permeability
cardiac depression |
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Term
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Definition
no evidence of involvement of IgE
presumably direct activation of mast cells and basophils |
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Term
| common causes of non-IgE mediated anaphylaxis |
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Definition
radiocontrast media
physical factors
idiopathic |
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Term
| What labs can you look at to help diagnose anaphylaxis? |
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Definition
plasma histamine: elevated soon after onset but declines within 1 hour
plasma tryptase: increases within 3 hours of symptom onset but not elevated with food-induced anaphylaxis |
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Term
| What are the types of anaphylaxis (based on clinical coures)? |
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Definition
uniphasic (most common): symptom onset, peaks 30min-1hour, resolves spontaneously or w/treatment within 30min-1hour
biphasic: uniphasic response>resolution>asymptomatic period >1hr>return of symtoms w/out further exposure to antigen
protracted: symptoms last hours to days without resolving completely |
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Term
| What are the most common causes of fatal anaphylaxis? |
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Definition
| foods, medications, insect stings |
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Term
| Causes of anaphylaxis fatalities |
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Definition
food-induced: resp arrest
venom/medication: CV collapse/schock |
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Term
| What are risk factors for poor outcome after anaphylaxis? |
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Definition
asthma
CV disease
B-adrenergic blockers (may decrease effects of epi)
failure to administer epinephrine rapidly |
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