Peter Lio, MD: Classifying Itch

Although a singular sensation, itch can originate from various underlying causes.

In order for dermatologists to properly treat the symptom—which can have an impact on quality of life—they must be sure to classify it accordingly.

In the latest episode of Derm Discussions, Peter Lio, MD, Clinical Assistant Professor of Dermatology & Pediatrics, Northwestern University Feinberg School of Medicine, explained the different ways itch can be categorized.

He cited Gil Yosipovitch, MD, of the University of Miami, or the proclaimed “Godfather of Itch.”

As such, itch can be classified in the following ways:

• Dermatological causes (i.e. atopic dermatitis)
• Neuropathic itch (small fiber polyneuropathies, brachioradial pruritis)
• Psychogenic itch (stress, anxiety)
• Systemic itch (renal disease)

Itch can also be identified as either acute or chronic—which, of course, will inform how a clinician proceeds with treatment.

Furthermore, Lio emphasized the importance of maintaining distinction between the 2 different types of itch-sensitive neurons.

“First, there are those that are the histaminergic pathway,” he said.

“But then there is an entirely independent of pathway of non-histaminergic mediators of itch. I think this is so confusing, especially for diseases like atopic dermatitis where people say, ‘well, put them on an anti-histamine.' But it really makes sense that it’s not going to work if it’s a different pathway.”

Lio further acknowledged that research into different itch-causing pathways is ongoing, but investigators and clinicians are continuing to learn more each day about these complexities and classifications.

Listen to the full podcast epiosde below: