Pruritis is a symptom of disease that manifests as itching. It is one of the most common dermatological complaints. Disorders causing pruritus may be dermatologic, systemic, neurologic, or systemic.

Why does pruritus occur?

Pruritus functions to respond to cutaneous sensations with the scratch reflex with the intent to remove the substance causing the sensation. This process involves the transmission of signals from peripheral C-nerve fibers to the central nervous system. Substances that stimulate C-fibers are called pruritogens and include:

  • Histamine
  • Serotonin
  • Prostaglandins
  • Substance P
  • Mechanical factors such as heat and dryness

Source: Tivoli, Y. A., & Rubenstein, R. M. (2009). Pruritus: an updated look at an old problem. The Journal of clinical and aesthetic dermatology, 2(7), 30–36.