s or ointments employed in acute
eczema are to be prescribed.

#Is a dermatitis due to too active and prolonged treatment ever mistaken
for persistence of the scabies?#

Yes.

#Pediculosis.#
(_Synonyms:_ Phtheiriasis; Lousiness.)

#Define pediculosis.#

Pediculosis is a term applied to that condition of local or general
cutaneous irritation due to the presence of the animal parasite, the
pediculus, or louse.

#Name the several varieties met with.#

Three varieties are presented, named according to the parts involved,
pediculosis capitis, pediculosis corporis, and pediculosis pubis; the
parasite in each being a distinct species of pediculus.

#Pediculosis Capitis.#

#Describe the symptoms of pediculosis capitis.#

Pediculosis capitis (_pediculosis capillitii_), due to the presence of
the pediculus capitis, occurs much more frequently in children than in
adults. It is characterized by marked itching, and the formation of
various inflammatory lesions, such as papules, pustules and
excoriations--resulting from the irritation produced by the parasites
and from the scratching to which the intense pruritus gives rise. In
fact, an eczematous eruption of the pustular type soon results, attended
with more or less crust formation. In consequence of the cutaneous
irritation the neighboring lymphatic glands may become inflamed and
swollen, and in rare cases suppurate. The occipital region is the part
which is usually most profusely infested, more especially in young girls
and women. In those of delicate skin, especially in children, scattered
papules, vesico-papules, pustules, and excoriations may often be seen
upon the forehead and neck. In some instances, however, especially in
boys, there may be many pediculi present, with but little cutaneous
disturbance, the itching being the sole symptom.

[Illustration: Fig. 79.
Pediculus Capitis x 25. (_After Duhring._) Female. Dorsal surface.]

In addition to the pediculi, which, as a rule, may be readily found, their
_ova_, or _nits_, are always to be seen upon the shaft of the hairs,
quite firmly attached.

#Describe the appearance of the ova.#

They are dirty-white or grayish looking, minute, pear-shaped bodies,
visible to the naked eye, and fastened upon the shaft of the hairs with
the small end toward the root.

[Illustration: Fig. 80.
Ova of the head-louse attached to