Transcript
Neal Bhatia (00:04):
Hi, I'm Dr. Neal Bhatia. I'm Chief Medical Editor of Practical Dermatology. And this is another installment of the Type 2 Journal Club. And I'm with my best friend, Dr. Larry Green. So, Larry, let's talk about some updates on prurigo nodularis and figure out what's going on.
Lawrence Green (00:19):
Well, I think this is a perfect article for the Type 2 Inflammation Journal Club because prurigo nodularis, and they also include chronic prurigo, are both conditions where you see Type 2 inflammation. And this article showed an elevated risk of lymphoma in patients who have prurigo nodularis as well as chronic pruritus of undetermined origin.
Neal Bhatia (00:37):
So, it's interesting, right? We think of CTCL, we think of cutaneous lymphoma, we think of all these other diseases as non-specific spongiotic dermatosis or whatever else. Tell me about what your spectrum is for understanding that diagnosis.
Lawrence Green (00:53):
So, for me, this is really interesting and it makes sense. It follows that you would have an increased risk of lymphoma in patients with prurigo nodularis and conditions like that. Because you think about it, whenever you have chronic inflammation, whether it's Type 2 or even Type 1 chronic inflammation, it's a task on the immune system. It's very hard for the immune system to keep up. Chronic inflammation is a stress on the body. And when the body has stresses, like we see in other conditions like psoriasis, which is Type 1, but we also have an increased risk of lymphoma. So, my theory is that, and I think we see this panning out in chronic inflammatory conditions, risks of lymphoma will be increased because the body's immune system is constantly stressed and revved up and the body can't cope. This is what happens.
Neal Bhatia (01:36):
Which makes perfect sense. And then you go back to a dendritic cell surveillance of everything else. You would think about Type 2 inflammation, but also Type 1 and IL-17 and all the overlap. But talk about itching as a precursor. What do you see in your patient population that says, "I have non-specific itching. I don't know what's going on. When do I follow that pathway?"
Lawrence Green (01:57):
Non-specific itching is so non-specific, unfortunately. And a lot of times it's in the elderly. And in the elderly it can be for a myriad of reasons, renal failure or renal insufficiency being one of them, but that leads to more inflammation. So, it just pends to the whole course of chronic inflammation leading to stress on the immune system, et cetera. But these people who are itching have to be worked up. We want to know why they're itching. And sometimes we don't find the answer. But that said, I think it's important to work them up. And then the more they itch, the more they're going to have immune system activation, the more the process can get going to have chronic inflammation.
Neal Bhatia (02:31):
No. I think that's actually the perspective we need to take. And it's funny because you think about dermatologists and itching. And we often dismiss it with antihistamines and everything else, but we need to get under the hood and make sure we're not missing diagnosis like this.
Lawrence Green (02:45):
100%. Antihistamines are really... When you think about it, how much of itch is usually due to histamine? Unless it's urticarial, antihistamines are a waste of time. So, we really do need to get under the hood to look for causes. And there's neuropathic itch, et cetera, which goes with inflammatory itch, lots of times hand in hand. And we have to look in the causes, not just for inflammatory itch, but also neuropathic itch. So, things like prurigo nodularis have a big component of neuropathic itch.
