Urticaria 1

Published on April 27, 2016   31 min

Other Talks in the Series: Skin Biology

Hi, my name is Lauren Fine. I'm an Assistant Clinical Professor of Internal Medicine in the Department of Pulmonary, Allergy, Critical Care, and Sleep Medicine at the University of Miami, Miller School of Medicine in Miami, Florida. Today, we're going to be talking about topic of Urticaria.
At the conclusion of this activity, you should be able to do the following: One, define the current classification of urticaria. Next, understand the impact of urticaria on your patients' quality of life. Three, explain the pathophysiology of urticaria and proficiently recognize the symptoms associated with urticaria. You should be able to describe different conditions related to chronic urticaria populations. You should be able to also describe the appropriate treatment for chronic urticaria, according to the clinical guidelines and international standard. And lastly, you should be able to interpret the results of research on old and new, and emerging treatments for chronic urticaria to make appropriate and personalized treatment decisions based on the current evidence.
I'd like you to take a look at these three photos and ask yourself if your patient came in with one of these rashes, would you recognize any of these as urticaria? Or would you wonder if any of these could be urticaria? And next, I like you to think about whether A, B, C, or more than one represents urticaria. In reality, the first is a photo of Bullous Pemphigoid. Bullous Pemphigoid, although it is a blistering skin condition, can present with an urticarial phase, where initially, the skin has an urticarial appearance prior to the presentation of the blistering. The second of photos does represent urticaria. So if you choose this, you're absolutely correct. And the last is a photo of urticarial vasculitis, which is a comic mimic of urticaria. We are going to go over some of the other conditions such is bullous pemphigoid and urticarial vasculitis later on in further detail.
This is larger photo of the photo on the previous slide, as well as picture of a patient's back where urticaria has affected the majority of a surface area of his back. And the trunk is one of the most common places to see urticaria. Urticaria can appear in different morphologies, because urticaria does not always take on the same morphology in every patient or every time that it appears even in the same patient. It's most important to recognize the edema that occurs with urticaria, and that it often appears on erythematous base. Sometimes the urticarial lesions will actually coalesce with one another and create a larger area, which you can see in the photo on this slide.
The features of urticaria are very important to understand, the appearance is very similar to a skin response with a histamine prick, such as when we do skin testing in an allergy clinic. And the photo on this slide is actually a photo of my colleague, after she had a skin prick with histamine. But this is the exact appearance that urticaria can take on and the classic appearance of urticaria. Classically, you'll see it in erythematous elevation in a circumscribed or coalescent wheal. And the wheal can be blanched and may not appear erythematous. The lesions are typically pruritic. But sometimes, they can be painful or burning. And in that case, you would consider urticarial vasculities or erythema multiforme in your differential diagnosis.
As I mentioned, the urticarial wheals may be blanched, but if they are not, they should blanch with pressure, which indicates the presence of dilated blood vessels and edema. Each lesion should resolve in about 24 to 36 hours. However, urticaria may be present on the skin for a constant basis for weeks, months, or even years. So it's important to understand when you're asking your patient this history, whether each lesion is resolving fairly quickly within about 24 hours or whether each lesion is persistent for days or even weeks. For example, in urticarial vasculitis, each lesion will remain there for days or weeks, and the patient may be under the impression, when they have urticaria, that it's a constant problem. And it is, but each lesion should come and go. So that's something that you should understand and help your patients understand. One thing I typically like to do is ask a patient whether a lesion would disappear within 24 hours, if they were to circle it and watch it. And that can be very helpful in differentiating urticaria from other skin conditions when the patient isn't sure and the morphology isn't as clear as it should be.
Approximately 25 percent of people will experience acute urticaria and/or angioedema at some time in their life. So the point of this is that urticaria is extremely common and when patients come in to our clinics and they're very concerned about the rash that they are experiencing, we need to reassure them that it's a very common condition, and also reassure them that it very frequently goes away pretty quickly. Even if it's not something that will go away quickly, such as if it becomes chronic urticaria, we need to explain to them, also that it's not something dangerous and it's something that we can usually control very easily.