Image of the Day: Light Salve
Image of the Day: Light Salve

Image of the Day: Light Salve

Researchers used infrared light to relieve itchy mice.

Jan 2, 2019
Carolyn Wilke

ABOVE: Mouse skin with the skin disease amyloidosis before and after treatment
PAUL HEPPENSTALL AND LINDA NOCCHI / EMBL

Chronic skin conditions such as eczema come with lots of bothersome itching, sensed by nerve cells in the skin’s upper layer. And while scratching feels good in the short term, it can lead to skin damage, inflammation, and more itching. Researchers have figured out how to stop itching in mice using light. 

They engineered a light-sensitive chemical that binds to the itch-sensing nerve cells and injected it into the mice’s skin. When they illuminated the skin with a near-infrared light, the chemical caused those nerve cells to retract and stop itching. 

The researchers observed that the mice with eczema and amyloidosis, a rare skin disease, scratched less after the treatment. In the pictured mouse skin samples, they also saw that debris that causes discomfort and skin roughness were reduced so that the skin could heal. 

L. Nocchi et al., “Interleukin-31-mediated photoablation of pruritogenic epidermal neurons reduces itch-associated behaviours in mice,” Nature Biomedical Engineering, doi:10.1038/s41551-018-0328-5, 2018.