Etiology.- Scabies is one of the few diseases of which we can say that we absolutely know the cause; and yet there is no chapter in medical history more interesting that that which concerns the etiology of this affection.
The acarus is exceedingly minute, and when first hatched has but six legs. It soon assumes its adult form, however, with eight legs; and the sexes are easily distinguished by the fact that in the female the four posterior legs are furnished with projecting hairs, while in the male two of these legs terminate in suckers instead of hairs.
Diagnosis.- The diagnosis of scabies should not in most cases be difficult. The early vesicles on the hands are either to be found, or the patient may tell you that the affection commenced with small “watery pimples.” Next, examine the penis, and you will rarely miss finding papules on the glans or papules or vesicles on the cutaneous surface. Rather good-sized isolated pustules about the wrists are commonly present, and in women you usually find an eczematous eruption around the nipple. If on inquiry you find that one or the other of the patient’s associates is suffering from a similar trouble, and that he has slept with him or worn his clothes, you may be fully confident of the diagnosis.
The mere presence or the intensity of the itching can not be relied on to establish the nature of the disease, as in several other affections, intense pruritus is a marked feature; and this is notably the case in phthiriasis, produced by the pediculus corporis, or body louse. The papules or other lesions on the penis should not be mistaken for lesions of venereal origin.
To briefly sum up, then, the diagnostic points are:
1. A history of contagion.
2. the development of minute papulo-vesicles or vesicles, spreading on contiguous portions of the skin or on parts habitually handled by the patient (never in patches but in rather a scattered manner.)
3. Itching, worse at night and becoming progressively worse as larger areas become invaded by the itch-mite.
4. Sites of predilection shown by the disease. They are the webs of the fingers, the front of the wrists, the anterior edges of the axillae, the mamma, the penis, the abdomen and groins, the toes and feet. Flexor surfaces are more involved than extensor.
5. That the face remains free from the disease, except in the case of infants at the breast.
6. That it has taken about three weeks for the disease to involve the whole surface.
7. That old cases show all the lesions that can possibly be produced by disease of the skin, expressed by the term multiformity of lesions.
8. Incidentally-numerous scratch-marks.
9. The itch-mite and its canaliculi.
Treatment – However distressing the present symptoms, the patient may be confidently assured of speedy relief. This may be most promptly brought about by adopting the following somewhat vigorous treatment: Put the patient into a warm bath and let him soak for fifteen or twenty minutes. Then let him be rubbed thoroughly all over with soft soap, assisted with a fleshbrush. Every part of the body from the neck down should receive a thorough application of the soft-soap and water and brush, in order to break over the burrows of the insects. The soap is then washed off and the surface rubbed dry. Then rub the entire surface with alkaline sulphur ointment to each ounce of which a drachm of iodide of potassium has been added. After a thorough inunction the patient should go to bed and stay there until the following morning. When morning comes a warm bath should be given to remove the ointment, and the patient should put on new under- clothes. The under-clothes and bedding that have been in use should be thoroughly disinfected by boiling or baking, in order to destroy any wandering acari. This treatment is effective but harsh, and for a day or two the patient’s skin will be far from comfortable, and the eczematous and other secondary lesions will be greatly aggravated. Emollient treatment, therefore, will in almost every instance be needed for a few days longer, and the use of the oxide of zinc ointment is as good as any.
One of the following Rx’s is, I think, far preferable, and less annoying to the patient:
Rx Beta naphtholi,
Balsam Peru, aa gm. x
Sapon, kalini viridis,
Cretae albae pulveris, aa gm. xx
Vasogen. Sulph (3 per cent.) spiss. gm. x L. M. f. unguentum.
Twenty-four hours’ covering of the affected parts is sufficient in most cases.
Or, Rx Sapon. med., 100.
Ol. petrae., Alcohol, aa 50.
Cerium alb., 40.
M. sig.: soap the whole body with this three or four times daily and the itch-mite will be destroyed.
Another, which has proved very efficacious in destroying the acarus scabiei, is: Rx Naphthol, 15.
Lard, 100.
Green soap, 50.
Prepared chalk, 10.
M. ft. Unguent.
For obstinate cases the following is excellent: Rx Petroleum, 50 parts.
White wax, 40 parts.
Alcohol, 50 parts.
Soap, 100 parts. M. Sig.: apply locally.
Remedies indicated:
Arsen. alb.- Inveterate cases; eruption in the bends of the knee; pustular eruption, burning and itching; better from external warmth.
Carbo veg.- Eruption dry and fine, almost over the whole body, worst on extremities; itching worse after undressing; dyspeptic symptoms, belching of wind and passing flatus; after abuse of mercurial salves.
Causticum.- After abuse of sulphur or mercury; yellowish color of face; warts on the face; involuntary urination when coughing, sneezing, or walking; sensitive to cold air.
Croton tig.- Itching and painful burning, with redness of skin; formation of vesicles and pustules; desiccation, desquamation, and falling off of the pustules.
Hepar.- Fat, pustular, and crusty itch; also after previous use of mercury.
Lobelia.- Pricking itching of the skin all over the body.
Lycopodium.- Humid suppurating eruption, full of deep fissures; itching violently, when becoming warm through the day.
Mercurius.- Fat itch, especially in the bends of the elbows, if some of the vesicles become pustular; itching all over, worse at night when warm in bed; sleepless at night from the itching; diarrhoea.
Psorinum.- Inveterate cases, with symptoms of tuberculosis; also, in recent cases, with eruptions in the bend of the elbows and around the wrists; repeated outbreak of single pustules after the main eruption seems all gone.
Sepia.- After previous abuse of sulphur; itching worse evenings, especially in females.
Sulphur.- Main remedy; voluptuous tingling, itching with burning and soreness after scratching; worse in warm bed; disposition to excoriation; glandular swellings.
Acid Sulphuricum- When itchiness of skin and single pustules appear every spring; after imperfectly cured itch.
VEGETABLE PARASITIC DISEASES.
Favus.
Favus is a parasitic disease of the skin caused by a minute vegetable fungus.
This disease may affect any portion of the body where there are hairs; but it prefers the scalp, especially the scalps if scalps of children. The fungus on which the disease depends is called Achorion Schonleinii, and falling on a congenial soil, gains access to the hair follicles, where it spreads and multiplies. In a short time it is perceived on the surface as a whitish speck, and later forms a very light-yellow umbilicated crust, the centre of which is perforated by a hair. A number of contiguous cups may coalesce, forming a crusty patch. The fungus, by its development and increase, presses on the follicular contents, and interferes with the nutrition of the hairs, and in time insures their destruction and permanent disappearance. Favus of the scalp usually makes its first appearance in childhood. Spontaneous cure rarely, if ever, occurs; and the affection lasts indefinitely-that is, as long as there is a hair follicle left for the achorion to lodge in. In this way the affection may be prolonged for twenty years or more. The most striking features of a long-standing case are the sparseness of the hairs over the affected area, the appearance presented being entirely different form that of any of the commoner forms of alopecia. The peculiar crusts may be present to aid the diagnosis, but not infrequently they are entirely absent from the surface, as various ointments, or even plenty of soap and water, are sufficient to prevent their development on the surface to an extent to prevent them to be visible to the naked eye.
The progress of the affection is extremely slow, and, when not checked by efficient treatment, may last for twenty years or more.
Favus on the body – that is, on the trunk or extremities first exhibits its presence by a small erythematous patch like a commencing ringworm; this spreads until it has a diameter of an inch or more, when the characteristic crusts appear.
Etiology.- The disease is due to a vegetable parasite, and is communicable from on to another. This disease is not infrequent in the common domestic mouse, from which animal it is sometimes conveyed to the household cat, who in turn transmits it to the children of the family.
Diagnosis.-In most cases the diagnosis is easy. If the affection is in full efflorescence, it can hardly be mistaken for anything else, as there is no other disease that presents the characteristic umbilicated, light yellow, and dry crusts. In an advanced case the peculiar alopecia, marked by the presence of a few, scattered, lustreless hairs, distinguishes it from every other form of baldness. In doubtful cases the microscope will reveal the parasite, which consists of minute spores and mycelium.
