Dr. Richard Thomas interviews Dr. Martin Steinhoff about his lecture on pruritus or itch, at the inaugural Stuart Maddin Lecture Series at Dermatology Update 2016.
Although itch is such a central symptom to many of the diseases that dermatologists encounter, our understanding of its mechanisms has been lacking. Dr. Steinhoff discusses the complexities of itch, and the importance of differentiating different types of itch, which may require different therapies. Various cytokines and receptors may be involved, with different diseases dysregulating different receptors–it’s isn’t a singular problem and this is why antihistamines are effective for certain types of itches.
Dr. Thomas: Martin, you recently gave a talk on itching–pruritus. What are the key messages from that talk?
Dr. Steinhoff: The main message is that itch or pruritus is the most frequent symptom which family physicians and dermatologists see among patients. To recognize as a physician that we have on one hand, very frequent disease, on the other hand, a poor understanding of the pathophysiology, about the diagnostic tools, about the therapeutic algorithms. We need to understand that the disease is very important for physicians to deal with on a daily basis.
We had made substantial progress in the last 10 years in the pathophysiology of itch, compared to pain, which is probably 30 to 40 years ahead. This has led to significant progress in identifying new therapeutic targets. This can explain why histamine is not the only target, and why antihistamine don’t work in several subtypes of itch and that cytokines, proteases, neuropeptides, are very important mediators in peripheral itch, and also in central itch. Peripheral and central itch has to be differentiated.
Also, with respect to future therapies, and that it’s exciting now to live in this time as a dermatologist because we probably have, in the next 5 to 10 years, several new therapeutics that will help itch patients and to treat this debilitating symptom.
Dr. Thomas: What are the targets for new therapies? Tell us more about peripheral and central itch.
Dr. Steinhoff: There are several itch receptors which have been identified on peripherals, sensory nerve, which are cytokine receptors like IL-4 receptors, IL-13 receptors, IL-31 receptors, TSLP receptors, and protease receptor, neuropeptide receptors, even tall-like receptors, so a huge amount of receptors plus iron channel. The next substantial question will be, which of these receptors will be dysregulated in which disease? In atopic dermatitis that it’s different from CTECL, different from Lichen Planus, different from other inflammatory pruritic diseases. That will be a very important future task to deal with. On the central level there are several neuropeptide receptors and neuropeptides identified which could also be targets for future therapy like brain derived natural peptide, custome using peptide, and like opioids, and again, in the human system it’s very poorly understood in which diseases they are dysregulated.
Dr. Thomas: Thank you very much for that summary. Thank you for the work that you, personally have done, for making progress and pushing the field forward. We certainly look forward, and there’s a huge need, from a patient point of view, for new therapies, so thank you.
Dr. Steinhoff: Thank you very much. Great pleasure.