a and like diseases.

#Pruritus.#

#What do you understand by pruritus?#

Pruritus is a functional disease of the skin, the sole symptom of which
is itching, there being no structural change.

#Describe the symptoms of pruritus.#

The sole and essential symptom is itchiness, usually more or less
paroxysmal, and worse at night. There are no primary structural lesions,
but in severe and persistent cases the parts become so irritated by
continued scratching that secondary lesions, such as papules and slight
thickening and infiltration, may result. It is much more common in
advanced life--_pruritus senilis_. In such cases, as well as in those
cases in younger and middle-aged individuals in which the itchiness
develops at the approach of cold weather and disappears upon the coming
of the warm season (_pruritus hiemalis_), the pruritus is usually more
or less generalized, although not infrequently in the latter the legs
are specially involved.

In some individuals an attack of pruritus, of variable intensity,
lasting from five to thirty minutes, comes on immediately after a bath
(_bath-pruritus_). It is usually confined to the legs from the hips
down.

#Is pruritus always more or less generalized?#

No; not infrequently the itching is limited to the genital region
(_pruritus scroti_, _pruritus vulvae_) or to the anus (_pruritus ani_).

#To what may pruritus often be ascribed?#

To digestive and intestinal derangements, hepatic disorders, the uric
acid diathesis, gestation, diabetes mellitus, and a depraved state of
the nervous system.

Pruritus vulvae is at times due to irritating discharges, and pruritus
ani occasionally to hemorrhoids and seat-worms.

#Is there any difficulty in the diagnosis of pruritus?#

No. The subjective symptom of itching without the presence of structural
lesions is diagnostic. In those severe and persistent cases in which
excoriations and papules have resulted from the scratching, the history
of the case, together with its course, must be considered. Care should
be taken not to confound it with pediculosis. In this latter the
excoriations usually have a somewhat peculiar distribution, being most
abundant on those parts of the body with which the clothing lies closely
in contact. (See Pediculosis corporis.)

In pruritus of the genitocrural region the possibility of pediculi being
the cause must be kept in mind; an examination of the parts fo