Urticaria and Angioedema Flashcards
definition of acute vs chronic urticaria
acute < 6 weeks and chronic > 6 weeks
*1% may develop chronic
gender predominance urticaria
F»_space; M for chronic, dermatographism, and cold urticaria and M > F for pressure urticaria
primary cell type responsible for urticaria
Mast cells
what are the inflammatory mediators produced by mast cells
Preformed: HISTAMINE, proteases, heparin
Newly formed: PROSTAGLANDIN D2, LEUKOTRIENES C4/D4/E4
What is the pathogenesis of urticaria?
- Immunologic: autoAbs against FCER1 or IgE dependent allergic response; drug induced
- Non-immunologic: opiate mediated release of C5a anaphylatoxin, substance P and VIP
- Immune complex deposition (urticarial vasculitis)
- vasoactive stimuli:
What vasoactive stimuli/meds can cause urticaria
nettle, ASA/NSAIDS, radiocontrast media, polymyxin B, ACEi (due to inc bradykinin)
3 MC acute urticaria
idiopathic > URIs > betalactams/drug
diseases a/w chronic urticaria
autoimmune thyroid disease vitiligo IDDM RA H pylori gastritis
how long does chronic urticaria last
3-5 years
urticaria at waistline
delayed pressure urticaria (can occur up to 12 hrs after stimuli)
difference between heat induced urticaria and cholinergic urticaria
heat = more localized
cholinergic: generalized papular wheals
blanched vasocontricted halos around pink wheal
adrenergic urticaria
*induced by stress
disease a/w aquagenic urticaria
cystic fibrosis
+ ice cube test in ___ and - ice cube test in
+ in primary cold contact (usu young adults, exposure to cold weather, holding cold objects)
- in reflex cold urticaria (results from generalized cooling of body)
what activity do pts with cold urticaria have to be counsled about
can never swim alone (can get hypotensive from massive inflammatory mediator release)
