Research revealed that the itching experienced by patients with atopic dermatitis may not be due to inflammation but instead caused by the bacterium Staphylococcus aureus and its impact on nerve cells. This novel finding challenges the common assumption that inflammation is the primary cause of itch in these patients. The study used a mouse model to test various bacteria and found that S. aureus caused itch, leading to an itch-scratch cycle, skin damage, and alloknesis, a hypersensitive response to gentle stimuli. The researchers discovered that the serine protease V8 from S. aureus triggers itch by activating the protein PAR1 on skin neurons, proposing that inhibiting V8-PAR1 signaling could be a new treatment strategy for itch.

The study’s findings suggest that PAR1 inhibitors, currently used for atherothrombosis, could potentially be developed into topical creams to control itch in patients with chronic skin conditions. This discovery is significant as it indicates that itch can occur independently of inflammation, although it can exacerbate skin inflammation. This research work opens new avenues for understanding and treating itch in atopic dermatitis and other chronic skin conditions.

Reference: Olmstead S. Atopic Dermatitis Itch May Be Caused by Microbes, Not Inflammation. Dermatology Times. Published February 23, 2024. Accessed May 29, 2024. https://www.dermatologytimes.com/view/atopic-dermatitis-itch-may-be-caused-by-microbes-not-inflammation