Urticaria Flashcards
what is a urticaria?
vascular reaction of skin leading to a wheal surrounded by a blanchable red halo
what is cardinal symptom or urticaria?
pruritis
what is urticaria caused by?
swelling of the upper dermis
are most cases of urticaria acute or chronic?
acute
name four common classes of things that cause urticaria
idiopathic
post infectious
food
drug
which class of urticaria causes leads to the most chronic urticaria cases?
idiopathic
can urticaria be autoimmune? if so what type of urticaria and what antibody mediates?
chronic urticaria…mediated by IgE
what is dermatographism?
sharply localized edema where skin was rubbed that appears within seconds…most common type of physical urticaria
what are the two pathyphys mechanisms of urticaria?
immuno and non immuno
explain how immuno driven urticaria occurs
antigen binds IgE on mast cell surface leading to degranulation and histamine release that leads to vasodilation
explain how non immune drive urticaria occurs
direct mast cell degranulation by pharmacologic agents or physical mechanism
what is the treatment for urticaria?
anti histamines…1st and 2nd generations
what is the classic 1st gen anti histamine
diphenhydramine
what is the classic 2nd gen anti histamine
loratidine and cetrizine
what is the difference in angioedema and urticaria?
angioedema is caused by the same mechanism as urticaria but angioedema occurs in the deep dermis with subcutaneous swelling
