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< 6 weeks = Acute Urticaria
| • | no work-up before six weeks and treat empirically with anti-histamines |
IgE (type I hypersensitivity) – food vs. meds vs. latex
non-immunologic – meds vs. contrast
> 6 weeks = Chronic Urticaria
etiologies to consider:
| • | check dermatographism and elicit other physical urticarias |
| • | tap on sinuses and ask travel and dental history - infection? parasite, chronic dental infection, H. pylori, (hepatitis = "urticarial" |
| • | or symptoms - autoimmune etiology – |
| • | = histamine releasing IgG autoantibodies vs. FcεRIα (the high affinity IgE receptor of mast cells) |
| • | ~ 25-45% of chronic idiopathic urticaria (CIU) patients |
lab tests:
| • | CBC eosinophilia - drug, food, parasite infection; leukocytosis - chronic infection |
| • | punch biopsy neutrophilic urticaria resists anti-histamines, but may respond to dapsone or colchicine |
last resort:
| • | stool O&P (if eosinophilia) |
| • | refer to dentist (chronic dental infection) |
| • | refer to GI: 13C Urea breath test for H. pylori treatment = amoxicillin 500mg QID plus omeprazole 40QD X 2week, then omeprazole X 2 weeks |
treatment:
| • | maximize to – zyrtec 40QD and singulair 10QD |
| • | avoid ASA/NSAIDS, opiates, ACE inhibitors, alcohol |
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