a careful history and examination will be sufficient to make the diagnosis in most of the patients
detailed history - change in diet, medication; illness
examination - characteristic raised areas of the skin (weals) with redness in the surrounding area, blotchy areas can be seen when the weals fade before the surrounding area (1)
dermographism may be evident
the list of possible investigations is vast considering most cases are idiopathic
FBC - Hb, WBC, eosinophils, platelets
ESR
LFT's
Thyroid function test and thyroid autoantibodies
chest and sinus X-ray
urinalysis - bacteria
stool analysis - parasites
complement screen - including C1 esterase inhibitor
antinuclear antibody " skin biopsy - for urticarial vasculitis (2)
a good initial screening investigation is an ESR
the duration of weal's can be used to differentiate the clinical patterns of urticaria:
ordinary urticaria - weals usually lasts from 2 to 24 hours
contact urticaria - upto 2 hours
physical urticaria - disappear within an hour, in delayed pressure urticaria takes upto 2-6 hours to develop and upto 48 hours to fade
urticarial vasculitis - persist for days
angioedema - can last upto 3 days without treatment (2)
Annotations allow you to add information to this page that would be handy to have on hand during a consultation. E.g. a website or number. This information will always show when you visit this page.