168

HAIR FOLLICLES

[voi. vi

Clinical
features

Pathogeny

Treatment

6.-INGROWING HAIR

610.] This is a somewhat rare condition; I have scon it only in the
beard region of men, where it causes much discomfort. The patient
complains of "pimples' at the mouths of the hair follicles, as there is
generally some redness there. Some of the hairs run at an acute angle
with the skin surface and do not emerge in the line of the follicle; they
tunnel under the horny layer and in some instances fail to emerge at
all but become wound up like a watch-spring and cause inflammation.
The cause of this complaint is unknown; possibly the natural exit has
been blocked by hyperkeratosis, though scaling is not obvious; or it
may be due to the use of somewhat irritating soap and a blunt razor.

The hair may be released by running a sterile needle under the hori-
zontally lying shaft and hooking it free. If the patient ceases to shave for
a time, the condition ceases to arise. Failing this, the following course
may be advised: first, the use of a very sharp blade; secondly, a change
to a shaving soap that is known to be free from irritating qualities;
and thirdly, the use of salicylic acid 2 per cent in equal parts of alcohol
and glycerin after shaving. This keeps the horny layer soft and appar-
ently cures the condition.

Clinical
features

Morbid
anatomy

Histology and
bacteriology

Aetiology

Treatment

7.-TEIGNE AMJANTACEE (SHEATH PITYRIASIS)
611.] This rare disease, in my view identical with fausse teigne (see
IMPETIGO,), is better known in France than in England and, as it has
not an English name, may be called sheath pityriasis.
The disease affects the scalp of children in patches of various sizes.
At first sight it is liable to be regarded as microsporon ringworm,
because the patch seems to be covered with whitish stumps. On close
examination, however, these whitish cylinders are seen to be not
"stumps' but projections of horny tissue about one-eighth of an inch
long with unbroken hairs running through them. In addition there are
flat scales lying on the skin between the hairs. Occasionally the scaling
is so abundant that the patch looks as if melted wax had been dropped
over the area and had solidified on the skin and around the hairs.
Dubreuilh showed that microscopically the sheath consisted of a chain
of horny cones in close apposition and derived from the mouth of the
follicle. Various micro-organisms have been incriminated, but skilled
observers have failed to find any organisms in the horny growths and
have found them sterile on cultivation.
The cause is unknown. It is important to distinguish the disease from
microsporon. ringworm—which is easy, and also from underlying
endothrix infection—which needs careful investigation. The condition
is apparently not contagious.
Treatment with strong ointment of mercuric nitrate 10 per cent,