Scratching the Surface of Severe Itching


By Kylie Wolfe

What if all it took to cause an intolerable itching sensation was a gentle touch? Some people experience this problem daily. Unfortunately, there are no existing medications or anti-itch creams that can relieve this discomfort.

What should feel like an ordinary physical sensation is instead perceived as an itch, making normal day-to-day interactions and activities uncomfortable. Some types of clothing can even trigger this response, making it impossible to wear certain fabrics.

Itching for a Cure

Itching is linked to the number of mechanoreceptors in a person’s skin, according to a recent study conducted by researchers at Washington University School of Medicine in St Louis, Missouri. These receptors are formed by an interaction between nerve endings and tactile epithelial cells called Merkel cells near the skin’s surface.  s people age, they may experience a decrease in the number of these cells, causing them to lose their ability to block itching sensations.

In this study, scientists used a thin, nylon tool to spark a sensory response in mice. As mice age, the number of Merkel cells in their skin decreases, causing an increased itch response. Mice with dry skin experience this problem as well because they also lack the proper number of these cells.

Researchers also tested mice whose Merkel cells were genetically engineered to react to a chemical compound. When treated with the compound, the Merkel cells became activated, which decreased the animal’s desire to scratch when touched with the nylon tool.

Another focus of this study was Piezo2, a protein on the membranes of Merkel cells. Researchers found that this protein helps control Merkel cells, minimizing their response to an itch. This conclusion may lend itself to future treatment discoveries.

Future Studies

To further their understanding, researchers are now examining skin samples from patients who suffer from this problem. If the number of Merkel cells is fewer than normal, activating those cells might serve as a potential solution.

Researchers believe that having the ability to control these cells can help control touch-related itching and lead to more effective treatments in the future.

Discussion Questions

  • Discuss and draw the sensory pathway your body uses to understand messages from stimuli. Include the words stimulus, mechanoreceptor, Merkel cell, nerve ending, neuron, and central nervous system. How is this pathway interrupted as we age?
  • What are the other kinds of sensory receptors and what do they help us detect?


  • Stimulus
  • Mechanoreceptor
  • Nerve Ending