The history, neurophysiology, clinical aspects and treatment
of pruritus are reviewed in this article. The different
forms of pruritus in dermatological and systemic
diseases are described, and the various aetiologies and
pathophysiology of pruritus in systemic diseases are discussed.
Lack of understanding of the neurophysiology
and pathophysiology of pruritus has hampered the development
of adequate therapies. Nevertheless, the discovery
of primary afferent neurons and, presumably,
second-order neurons with typical histamine responses
mediating pruritic sensations can be regarded as a
breakthrough in our understanding of the mechanisms
behind pruritus. The number of experimental and
therapeutic studies has greatly increased during the
past few years, reflecting an increased interest in this
topic. However, further effort is needed to develop new
therapeutic concepts and clarify some confusion arising
from promising case reports and uncontrolled clinical
studies. A precise work-up for evaluating patients
with pruritus is proposed, which may help the physician
to identify the underlying causes and thus to treat
the patient appropriately.