SCABIES

Synonyms.—Itch; Fr., Gale; Ger., Krätze.

Definition.—A contagious disease due to the invasion of the skin
by the acarus scabiei_; characterized by itching and lesions of a papular,
vesicular, and pustular type, predominantly upon the fingers, hands,
wrists, axillary folds, lower abdomen, and genital and anal regions.

Symptoms.—The first evidence of the disease is itchiness, caused
by the presence of the itch-mite within the cutaneous tissue, at first
being limited to the region where the parasites have gained access.
On examination a few papules or vesicles may be discovered. The
malady is one of steady progression, getting, unless held in check by
daily washings, worse and worse as regards itching and the amount of
eruption. As a rule, when the patient seeks advice, the affection has
lasted for several weeks; the itching is more or less general, but more
pronounced on certain situations. Inspection discloses the presence
of papules, vesicles, and often pustules, in scant or great number upon
the hands, especially the fingers, the wrist, about the region of the
elbow, at the axillae, the lower abdomen, the genitalia, cleft of the nates,
inside of the thighs, and frequently about the ankles and feet. The
region of the nipple in women is also a favorite situation. Scattered
excoriations are to be seen here and there. Other parts of the body in
well-marked cases likewise show lesions, but they are always predomi­
nantly present on the situations just named. The head, except in infants
and very young children, rarely shares in the eruption. In addition to
these various lesions the burrow, or cuniculus, is usually to be found,
the common situations for it being the interdigital spaces, the flexor
surface of the wrist, about the mammæ in the female, and on the shaft
and glans of the penis in the male. It consists of a tortuous, straight, or
zigzag, dotted, slightly elevated, dark-gray or blackish, thread-like, linear
formation, varying in length from ¹/₈ to ¹/₂ inch; at one end slightly more
elevated, and appearing as a minute whitish or dark grayish dot is the
contained female mite.

The eruptive phenomena may be quite pronounced, especially in the
careless and uncleanly; and in such there may be an abundance of
variously sized blebs and pustules, in addition to vesicles, papules, ex­
coriations, and burrows. The inflammatory lesions are also always most
marked as regards development in those of irritable skin, and in such
individuals the burrows, except evidences on the vesicle, pustule, or
bleb-wall, are usually scanty in number and hard to find; the reactive
irritation of the tissue giving rise to a papule, vesicle, or bleb, the
mite thus being so soon disturbed the burrow cannot be formed or is

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1189

and neglected, and particularly in those predisposed to true eczema, in
addition to the multiform eruption of scabies, an eczematous aspect is
presented, especially about the hands, forearms, and axillary folds.
Impetiginous lesions and crusts are also often interspersed. Among the
lepers in Norway and in others, from neglect and long duration, more or
less massive crusting and calloused formations are sometimes noted—
Norwegian itch. In other instances, in those who are bathing daily, the
eruption is always scanty, and generally consists of scarcely more than
several or more insignificant papules or vesicles upon the various favorite
regions, with, as a rule, burrows likewise sparse. The itching of scabies,
as may be inferred from the common name, “the itch,'’ is usually of an
intense character. It is not so marked or violent during the day-time
as when the patient gets in bed and the skin becomes thus warmed up,
the parasites being apparently more active under such influence. In some
cases there is but little, if any, suffering during the day. The degree of
pruritus varies somewhat, too, in different cases.

Fig. 320.—Acarus scabiei (ventral surface): 1, Female; 2, male (X 100) courtesy of

Dr. L. A. Duhring).

The course of the disease, as already stated, is, as a rule, steadily
progressive, but in many instances, owing to frequent baths or soap-
and-water washings, the development is only of moderate character.
In fact, in many patients as met with in our dispensaries, and in the
majority in private practice, the malady never reaches the extent and
severity of the cases so common in the European clinics. Nor with most
of our patients are the hands ordinarily so predominantly involved as in
those seen in the latter countries. In those of certain occupations,
such as stone-cutters, bricklayers, polishers, pasters, etc., the hands,
from the character of the work and the frequent washing necessitated,
are, as a rule, the seat of but sparsely scattered lesions. With private
patients, many of whom as soon as they first notice itching begin to wash
diligently and frequently, the eruption is almost always scanty, consist­
ing of but a few lesions on wrists, axillary folds, lower abdomen, and
penis, and possibly between the fingers.

1190                          PARASITIC AFFECTIONS

Except as to the depression consequent upon, the distress and wake-
fulness produced by the itching, the general health does not seem affected,
although albumin has been occasionally found in the urine of patients
while subjects of the disease;¹ sometimes, possibly, due to the remedies
applied. Kolmer,² Schamberg³ and Strickler found an increase in the
eosinophiles.

Animal Scabies (of domestic animals) may be conveyed to man,
usually by more or less intimate contact, and provoke lesions similar
to those in the human variety; burrows are, however, seldom seen; and
apparently in the eruption produced by scabies of the cat⁴ the lesions
are mostly papular, later with apex vesiculation, papular excoriations
with crusting, and accidental coccic infection lesions. The distribution,
especially from cat scabies, is more largely truncal, rarely affecting, to
any great extent, the lower parts of the extremities.

Etiology and Pathology.—The disease is due to an animal
parasite, the acarus scabiei, sarcoptes scabiei, sarcoptes hominis, be­
longing to the class arachnidæ, in the subdivision acarinæ, and family
sarcoptidæ. It is contagious to a marked degree. It is most commonly
contracted by sleeping with those affected, or by occupying a bed with
unchanged linen in which an affected person has slept. It may, doubtless,
be also contracted in many other ways, which will readily suggest them­
selves. Its contraction is possible, although not so probable, from the
use of common towels and other toilet articles, tools, etc., and even from
shaking hands. For obvious reasons it occurs usually among the poor,
although it is occasionally met with among the better classes. It is seen
at all ages and in both sexes. It is much more common in Europe and
other countries than with us, but of late our dispensary and private
practice records show a marked increase over former years.⁵ It is not
infrequent in our own country to see many cases among the foreign-
born laborers, especially the Italians, Hungarians, and Poles, who, from
the natural flocking together and intimate contact, are soon, as the result
of the introduction of one or two fellows with the disease, largely affected
—hence the names sometimes heard, of “Italian itch,'’ “Hungarian itch,”
“Polish itch.” There are the same opportunities for its spread in
closely quartered armies, hence the term “army itch.” Some of the cases
reported as “prairie itch,” “swamp itch,” “lumberman’s itch,” etc., were

¹ Nicolas and Jambon, “L’albuminurie chez les galeux,” Annales, 1908, p. 65, con­
tribute the latest paper on this point, also fully reviewing the subject (with references).

² Kolmer, Jour. Cutan. Dis., 1911, p. 339, found in a series of cases (18) the disease
accompanied by a mild leukocytosis; the eosinophilia varied from 3 to 11 per cent., and
two­thirds of the cases were over 5 per cent., an average of 5.9 per cent.

³ Schamberg and Strickler, “Report of Eosinophilia in Scabies with a Discussion of
Eosinophilia in Various Diseases of the Skin,” ibid., 1912, p. 53, found in an examination
of 47 cases of scabies, 38, or more than 80 per cent., showed 5 or more per cent, of eosino-
philes; the maximum was 19 per cent., and the average 7 per cent., the patients exhibit­
ing no increase were for the most part those with scant eruption; this paper contains
a valuable review, with tabulations, of the important papers on eosinophilia and blood-
counts in the various skin diseases, with bibliography.

⁴ Thibiérge, “Sur l’eruption provoquée chez l’homme par la gale du chat,” Gaz.
des Hôpitaux, Jan. 31, 1911.

⁵ See following papers bearing on this point: Greenough, Boston Med. and Surg.
Jour., Sept. 23, 1886; J. C. White, ibid., Feb. 14, 1889; Stelwagon, Med News, Sept.
23, 1893-

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1191

cases of scabies, and some, doubtless, of pruritus hiemalis, although most
of them were probably examples of grain-mite dermatitis.

The eruptive lesions are the result of the irritation produced by
the presence and products of the parasite in the cutaneous tissue, reaction­
ary inflammation invoked, papules and vesicles and blebs resulting.
Purulent lesions are also produced, doubtless due to secondary inoculation
of pus cocci. The constant scratching gives rise to favorable opportuni­
ties for integumentary coccus infection.

The female mite is the one which invades the integument, the male
never being found in the cutaneous tissue, but in excavations in the skin,
and apparently takes no direct part in the production of the symp­
toms. The general appearances and characters of both are shown in the

Fig. 321.—Scabies, section of skin showing: B,B,B, Burrow; C, C, corneous layer; R,
rete mucosum; Cm, corium (courtesy of Dr. M. B. Hartzell).

annexed cuts. It is observed that the male is much smaller than the
female; the latter is about ¹/₇₀ inch long, and ¹/₃ less in width. They have
an oval body, the upper surface convex and transversely corrugated,
with some spinous projections; the lower or ventral surface is flat, with
four anterior and four posterior claws, the former being each provided
with a sucker and several hairs, the latter with long bristles. There is
a short, projecting head. The male differs from the female only in having
suckers also in the two inner posterior claws; it is provided with rather
conspicuous genital organs. The parasite does not invade the rete,
as has been commonly believed, but, as both Török¹ and Schischa²

¹ Török, “Zur Anatomie der Scabies,” Monatshefte, 1889, vol. viii, p. 360.

² Schischa, “Zur Anatomie der Scabies, nebst Beitrag zur Histologie der Horn-
schicht,” Archiv, 1900, vol. liii, p. 313 (with 3 plates and 11 cuts; with review of the
opinions of others).

1192                              PARASITIC AFFECTIONS

have shown, as previously indicated by Riehl, it penetrates the corneous
layer and traverses the middle or lower part of it. This is also well
shown in the annexed cut (Hartzell). As the mite burrows it deposits
ova, in variable number, finally perishing in the skin. The burrow or
cuniculus contains therefore the female parasite, ova, and excrementi-
tious matter; by snipping off this formation and placing under a magnify-
ing-glass or microscope with low power, the mite, ova, and products can
be readily seen. The mite can, if one is expert and has good sight, be
caught in the blind end of the burrow, where it reposes as a grayish or
grayish-black dot, by quickly transfixing it with a pin or needle. The
ova gradually hatch out, and thus the malady is continued and its extent
increased. It takes, on an average, about five or six days for the larva
to develop from the egg, and about twelve to fourteen days more to reach
full adult growth; at first the larva has only six legs.

Diagnosis.—But little difficulty need be experienced in the diag­
nosis of this disease if its characters are borne in mind: these are the
distribution, the multiformity of the eruption (papules, vesicles, excoria­
tions, and often blebs and pustules), the itching, usually marked at night
when the patient warms up in bed, and quite frequently a history of con­
tagion. The burrow, if carefully looked for between the fingers, in the
palms, on the wrist, and on the penis, can usually be found, and when
present is diagnostic The peculiar distribution is likewise commonly
sufficient to lead to a correct conclusion. The history of an itching mal­
ady, of progressive character, with eruptive evidences, such as described,
between the fingers and other parts of the hand, on the wrist, about the
elbow­ joint, axillæ, lower abdomen, genitalia, buttocks, and in women
also about the nipples, is always strongly suggestive, and generally con­
clusive. As the hands share in the eruption this factor, as well as the
other distribution, will serve to differentiate it from pediculosis corporis.
In this latter the irritation and consequent lesions are found upon cov­
ered parts only, especially those regions with which the clothing comes
closely in contact, as around the neck, across the upper part of the back
and shoulders, about the waist, and down the outside of the thighs—a dis­
tribution quite different from that in scabies. Moreover, in pediculosis
the parasite can generally be easily found in the clothing, especially in or
about the seam of the neck­band. Scabies bears some resemblance
to eczema, but with care can usually be readily distinguished from it
(see Eczema for differentiation), as well as from other itchy diseases.¹

²Luck has reported (Med. Record, Aug. 5, 1899) a curious mucor dermatosis,
with some resemblance to scabies, affecting chiefly the fingers, arms, and axillæ. The
eruption was of itchy character, was made up of small elevations connected by channels
running under the horny layer of the epidermis, and some small, dark-red pustules and
crusted spots. Small filaments protruded from some of the pustules, which on examina­
tion were found to consist of fragments of mycelia of a species of mucor, probably the
mucor corymbifer. Mercurial, chrysarobin, and ichthyol applications were unsuccess­
ful, but a 3 per cent, ointment of menthol and salol proved curative.

Castellani (Brit. Jour. Derm., Jan., 1913, p. 19) describes under the name of copra
itch an eruption very similar to that of scabies, both in character and distribution, ex­
cept that no burrows or cuniculi are present; it is observed in those working in copra
mills in Ceylon (copra being derived from cocoanuts); he found acari-like parasites in
the copra dust; Hirst (ibid., p. 21) found the parasite to be an acarus, belonging to the
genus Tyroglyphus, resembling and probably a variety of Tyroglyphus longior Gerv.—

SCABIES

1193

Prognosis.—The disease is readily and usually promptly cured
if the treatment is thoroughly and vigorously carried out. There is
no tendency to spontaneous disappearance. As soon as the parasites
and their ova are destroyed, the itching and the eczematoid or secondary
eruptive lesions as a rule rapidly disappear. In those predisposed to true
eczema this latter, which may have been provoked by the parasites and
scratching, may occasionally tend to persist even after the scabies proper
has been cured. Generally, however, such cases yield to continued sooth­
ing applications.

Treatment.—The treatment of scabies is purely external. There
are three remedies which have a special reputation in promptly curing
it. These are sulphur, balsam of Peru, and ß-naphthol. The first is
the one upon which chief reliance is placed, or at least that most fre­
quently prescribed, although either of the others is likewise sufficient
to destroy the parasites. Ointments containing two or all these ingre­
dients are commonly found the most satisfactory. For children and
those of delicate skin the following may be used:

R. Sulphur sublimat.,

Bals. Peruv.,                                                  ää 3-J-vj (8.-24.);

Adipis benzoinat.,

Petrolati,                                           ää q. s. ad 3iv (128.).

In those of the average dispensary or hospital class, this same com­
bination of full strength can also be satisfactorily employed, or one con­
taining ß-naphthol, as in the following:

R. Sulphur, sublimat.,                                            3-J-vj (16.-24.);

Bals. Peruv.,                                                      3-v (16.);

ß-naphthol,                                                        3j-ij (4-8.);

Adipis benzoinat.,

Petrolati,                                           ää q.s. ad 3iv (128.).

Before the ointment is applied the patient takes a hot bath, using plenty
of soap, and if the skin is not oversensitive, sapo viridis. All parts
should be thoroughly washed with a coarse wash­cloth, or in those of
rather tough skin with a brush; in this way the horny layer is softened
and the burrows and other lesions opened up for full action of the reme­
dial application. The ointment is then rubbed in vigorously over the
entire surface, below the chin line, rubbing in particularly well in those
situations where the eruption is most marked. In infants and very
young children in whom the face and possibly other parts of the head
may share in the parasitic invasion, these places must also receive atten­
tion. The ointment is rubbed in night and morning for two to four days,
the patient wearing the same underwear continuously. Ten or twelve
hours after the last application the patient takes a bath, changes his un­
derwear, and also the bed-linen. Thoroughly done, one such course
will suffice. Itching usually lessens or wholly abates after the first

the latter being of rather wide distribution and found on dried or preserved animal and
vegetable matter; Castellani states if the patient abstains from his work for some time
the condition disappears spontaneously; he found a 5 to 10 per cent. ß-naphthol oint­
ment useful.

1194

PARASITIC AFFECTIONS

application. Toward the last rubbing, slight itching may have again
appeared, due to the irritation excited by the sulphur, but this quickly
subsides as soon as treatment is discontinued. Not infrequently the
eczematoid eruption provoked by the malady or by the sulphur applica­
tions requires soothing remedies, such as named under Eczema. Some­
times the irritation excited by the sulphur is mistaken by the overzealous
for a continuance of the scabies, and the irritating application still
further, but unnecessarily, continued, the dermatitis or eczema being
thus kept up.

In exceptional instances of tough skin and marked development of
the malady the Helmerich ointment, as modified by Hardy, and in com­
mon use in Saint Louis Hospital in Paris, can be resorted to. It consists
of 2 parts of sublimed sulphur, 1 part of potassium carbonate, and 12
parts of lard. It is preceded by a prolonged washing or bath with hot
water and sapo viridis. Sulphur treatment is sometimes given in the
form of a bath, using 3 to 6 ounces (96.-192.) of potassium sulphuret
to 30 gallons of water, the patient soaking in this for from fifteen to thirty
minutes, rubbing himself thoroughly with a coarse wash­cloth or a scrub-
brush; one to three baths are usually necessary. The bath may also
be made with liquor calcis sulphuratæ; or this, weakened or full strength,
can be rubbed in the skin after an ordinary soap-and-water washing.
Sherwell¹ strongly lauds a plan of treatment with sulphur used as a pow­
der as being efficacious and much more cleanly than the ointment method,
although somewhat slower. After a bath the powdered sulphur, in small
quantity, is lightly rubbed in over the surface; a small quantity is also
sprinkled between the bed-sheets. This is repeated every two or three
nights, the bed-linen and underwear changed each time. Cure is effected,
it is stated, in a week or ten days.

The balsam of Peru itself, as already remarked, is sufficient, and
might be employed in those exceptional instances in which the skin
is extremely sensitive or predisposed to eczema. It is a routine method
in certain foreign centers, and has been warmly commended by Peters,
Burckhardt, Nothnagel, Jullien and Descouleurs,² and others. Ex­
perimentally it has been shown to be much more rapidly fatal to the itch-
mite than sulphur. It is brushed over the entire surface, and allowed to
remain on over night; in extreme examples somewhat longer, and, if
necessary, a fresh application made.

An important point in the management of scabies is the care of
the clothing, otherwise the patient is reinfected over and over again.
The underwear, as well as the bed-linen, should be boiled, or, if the
former is woolen, in order to avoid shrinking, a thorough baking can
be given instead. The outer clothing and any other wearing apparel
that has had a chance at harboring the parasites must also be baked
or ironed with a very hot iron. Moreover, as there are often several
members of a family affected before the nature of the malady has been
ascertained, it is a matter of course that all should receive attention,

¹ Sherwell, Jour. Cutan. Dis., 1899, p. 494.

² Jullien and Descouleurs, “Trois cents cas de gale traités par le baume de Pérou,”
Annales, 1896, p. 577.

DRACUNCULUS

1195

otherwise the disease, through constant reinfection, may continue in
such a household indefinitely.

The treatment of animal scabies in man is to be much less vigorous.
The human skin is not a favorite habitat for the animal sarcoptes, and
often the removal of the infecting animal, along with soothing anti-
pruritic applications, such as a 1 to 2 per cent, carbolated Lassar paste,
with 1 to 3 grains of menthol incorporated, will suffice. A weak sul­
phur ointment may be used in some cases, but as Thibiérge points out
in cases in which the parasites do not get into the human tissues, as
apparently in scabies from the cat, sulphur preparations are apt to
irritate.

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