Scientists have discovered a specific type of immune cell, called GD3 cells, that plays a crucial role in determining how itchy a person gets after an allergic reaction, such as a mosquito bite. These cells release a signaling molecule called interleukin 3 (IL-3), which activates sensory neurons in the skin, making them more likely to trigger an itch. The research, conducted in mice, offers potential new targets for treating chronic itch disorders.