Hives (Urticaria)

00:03 Let's talk about Urticaria (Hives).

00:06 So what urticaria (hives), what does this mean to you? The IgE-mediated.

00:10 As soon as you hear IgE-mediated what does that mean to you? It means that now you've been exposed to a particular antigen, in which you have now elicited a Type 1 hypersensitivity.

00:20 Isotype switching, IgE then lands upon your IgE receptors of the mast cell.

00:25 And what did you release? Ah, histamine. Histamine, histamine.

00:30 Histamine has what can effect on your blood vessels? Vasodilation. Good.

00:36 Welcome to Hives.

00:38 Now once you have vasodilation taking place with the histamine being released by the mast cell You have an area that appears what? Maybe a little edematous.

00:50 Erythematous caused by food, medication, exercise, temperature, vibration, stress.

00:56 Those things that you can expect in which hives are going to develop.

01:00 And two to three episodes per week, for six weeks is a chronic urticaria.

01:06 Be familiar to define, or how to define chronic urticaria, which is two to three episodes per week for six weeks.

01:14 That is extremely cumbersome.

01:18 Morphology: Rapid development of edematous enie Edematous, why? Histamine, vasodilation, edema.

01:27 Erythematous, wheal formation.

01:30 There are three terms here that you want to keep in mind: urticaria, hives, and wheal formation.

01:35 To you, it's a type 1 hypersensitivity, with vasodilation, edema, and erythema.

01:44 These lesions evolve and dissipate rapidly within 24 hours.

01:49 And there's every possibility that if you were to take a glass slide, for example, and apply pressure, apply pressure on this hive or wheal formation with vasodilation, press upon that wheal please W-H-E-A-L, what's going to happen? Blanching.

02:07 Because when you press upon that wheal, the fluid edema is going to then disperse.

02:14 So that erythema that you found upon what's known as a diascopic type of examination is then going to give you your blanch type of appearance.

02:28 Diagnosis: Rapidly evolution, clinically distinctive, and biopsy rarely performed.

02:35 A history is going to tell you what's going to happen.

02:37 Take a look at the image here, high formation on the thigh and the leg of this individual.

03:08 Management: You need to identify what's actually causing the type I hypersensitivity.

03:13 Antihistamines obviously sedating, such as maybe diphenhydramine.

03:18 Moderately sedating will be cetirizine and non-sedating, if at all required based on the patient's habits and behavior, Maybe you're thinking about loratadine.

03:27 but anti-histamine, you are going after the histamine, so that you can take care of the hives.