[Pruritus--pathophysiology, clinical features and therapy--an overview].

Pruritus is an unpleasant sensory perception of the skin associated with the desire to scratch. As a physiological nociception, pruritus leads to the removal of harmful agents such as parasites and plants from the skin surface. More often, pruritus occurs as a severe and therapy-refractory symptom of various underlying dermatological and systemic diseases. Comparable to chronic pain, chronic pruritus worsens the general condition and may lead to physical and psychological exhaustion. Until the 1990s, pruritus had been regarded as an incomplete pain sensation. Only recently, itch was defined as a separate, pain-independent sensation with its own mediators, spinal neurons and cortical areas. These observations led to the development of new therapeutic modalities. This paper gives an overview of itch pathophysiology, clinical types and therapies.