Trying to Diagnose Chronic Urticaria - Medical Student-Style

Why do you need to check CMP (complete metabolic panel) in chronic urticaria? Please read this excerpt from the blog post below:

"On our third year clinical rotations, she developed hives. It was strange. We immediately assumed the role of medical student detective, trying to determine the source. She tried the non-latex gloves in the OR, to no avail. I remember one weekend, we decided to put all of the plants in her apartment on her back porch, to see if they were the culprit. We regarded her fish Kumar, named after the author of our second year pathology text, suspiciously - even though he was an unlikely candidate for her troubles.

The hives worsened, and became a chronic problem. She visited an allergy-immunology expert, and was loaded up on a triple-drug regimen, in order to try to gain relief on a Christmas visit with her parents to visit her brother in Italy. One night, shortly after returning from Christmas vacation, she called me frantically from the grocery store.

"I am standing in the aisles, looking at the signs for aisle content, and I can't read them. They're blurry. I've always been able to read the signs. What can this mean? I'm scared."

She went to an ophthalmologist, the next week. The ophthalmologist listened to her history, gave her an eye exam, and told her - let's look at your sugar. I am worried. It was sky high. She was diagnosed, in her early twenties, with Type 1 diabetes, about six months after her hives presented. As soon as her diabetes was treated, her hives disappeared."

Diagram (mind map) of acute urticaria (click to enlarge the images).

Diagram (mind map) of chronic urticaria (click to enlarge the images).

Trying to Diagnose Disease - Med Student Style. Mothers in Medicine, 2010.
Anti-FceR1 Autoantibodies in Chronic Urticaria
Image source: Urticaria, Wikipedia, public domain.


  1. Anonymous5/19/2010

    excellent post. While Alan Kaplan in his NEJM article suggested obtaining only TSH, thyroid antibodies,and CU index for chronic urticaria workup, there is a need to get CMP, and CBC with diff.

  2. Anonymous5/19/2010

    Don't forget IgG for Helicobacter pylori.

  3. Anonymous9/07/2011

    interesting post here .. does it also apply to other chronic allergy or only for urticaria ?

  4. Anonymous5/01/2012

    Another reason for a CBC. First Immunologist chalked up my daughter's light headiness, nausea, and other symptoms to reactions to anti-histamines for CAU. With each new drug we tried she seemed to feel worse. After asking for a larger work-up from that Doctor and being sent away with a recommendation that we seemed stressed out and could benefit from yoga, the second opinion ran a CBC and other tests which showed she was severely iron anemic. Been 4 months and she is still anemic, but feeling better. (Although CAU is always there if she is late with her antihistamines.)