whole line is merely a slightly raised erythematous thread-like formation, most pronounced at its extending part, and fading away at the older traversed part: The parasite travels at the rate of a fraction of an inch to several inches daily. It may take a tortuous, irregular, or erratic course, and even traverse a great part of the body. Exceptionally, there is more than one parasite present (rarely more than two), as in one of my cases, giving rise to a similar corresponding extending burrow. The formation is due to a minute migrating larva, which Sokolow and Samson-Himmelstjerna claim to have found. According to the latter it is more readily detected by pressing the blood out of the part by means of a flat piece of glass, through which, with the aid of a magnifying lens, the parasite can be seen as a black speck. In

one of my cases I was able to corroborate this, but I did not succeed in getting possession of the parasite.

This malady is met with most commonly in Southern Russia; it is rare with us, but during the last several years cases have been recorded, in the order named, by Van Harlingen, myself, Hamburger, and Shelmire. In almost all cases the starting-point of the lesion is on those parts most exposed to inoculation and invasion-hands or lower part of the forearm, the feet or lower part of the leg, and the buttocks or adjacent part of the back, In all of my 4 cases, and also in some instances reported by others, the malady began at or after a visit to the sea or seashore. According to Sokolow, the parasite, resembling the larva of a fly, is I mm. in length, with ten segments, and hooklets, with, at the head-end apparently, two suckers; he considered it the larva of a botfly, or œstreus, of the genus gastrophilus, probably of the species hæmorrhoidal. It was also stated by this observer that black nits could be found adherent to the hairs in the neighborhood of the bur

row.

In

Treatment usually advised consisted in excising or cauterizing an area around or just beyond the advancing part. my cases I applied cataphoretically a solution of mercuric chlorid 2 grains to the ounce (0.13 32.) to an inch-and-a-half area around the advancing end of the burrow, and applied a minute quantity of nitric acid to the suspected site of the parasite, just beyond the extreme end of the line; a magnifying glass should be employed to discover this point, as it is slightly in advance of where it appears to be by unaided vision. These cases were all cured within a week by this method, the cataphoretic application being repeated two to four times. Hutchins had marked success with the injection of a few drops of chloroform.

Craw-craw is a malady observed chiefly on the west coast of Africa, having to some extent the aspects of scabies, which is caused by nematodes, according to Nielly, a species of the genus leptodera and family anguillulidæ, and in Corre's and O'Neill's opinion to a kind of filaria. The fingers and forearms are always

1 Neilly, Bull. de l'acad. de med. de Paris, 1882, p. 395.

2 O'Neill, Lancet, 1875, i., p. 265.

predominantly, and sometimes exclusively, affected. The eruption, as to be inferred from its resemblance to scabies, consists of papules, vesicles, and pustules, discrete or crowded, and frequently with considerable crusting, and is exceedingly itchy. There are no cuniculi, however, as in scabies, nor the same peculiar distribution. The parasites in craw-craw can be found in the scrapings and in the seropurulent liquid.

The disease is rebellious to treatment, consisting of thorough cleanliness, baths, removal of the crusts, and sometimes the curetting-out of the underlying soft tissue, together with the use of parasiticides.

The echinococcus larva, while usually found affecting the internal organs, exceptionally gives rise (echinococcus cutis) to a softish, fluctuating, semitranslucent, projecting tumor, somewhat larger than those of the cysticercus. It is seated in the subcutaneous tissue, and has been found more frequently in women. The covering integument is unchanged. Encapsulation of the parasite takes place; it perishes in one or two years, the tumor undergoing calcification. There are no subjective symptoms except a sensation of tension and heaviness. According to Geber, the semitranslucent character of the tumor, its superficial seat, and projection without alteration of the skin, and the fluctuation are the features of diagnostic value; supplemented by exploratory incision and finding the hooklets of the parasite. Treatment consists of extirpation.

The distoma hepaticum, or liver-fluke, has, according to Küchenmeister, been found in the subcutaneous tissues of human beings in three instances, —one woman and two men,—giving rise to a tumor-like formation. In one the site was the region of the ear, another the lower extremities, and the third the trunk. The subjective symptoms varied, being practically nil, in one instance painful, suggestive of the pain of a developing abscess. Diagnosis was possible only by finding the distoma.

Ground itch or uncinarial dermatitis, observed in certain tropical countries (also called water-itch, water-pox, water-sores, sore feet of coolies, panighao; and in Porto Rico, also, "mazamorro ''), consists primarily of an erythematous or an erythemato-papular and papulo- vesicular eruption of the feet due to the irritation of these parts by the larvæ of the hookworm. Uncinariasis, ankylostomiasis, or hookworm disease (also known as dochmiasis, tropical chlorosis), is, as known, a serious, and when untreated, often fatal, constitutional malady characterized by depression of the vital forces, profound anemia and inertia. It is due to the intestinal parasite (probably of several varieties) known variously as uncinaria duodenalis, ankylostoma duodenalis, dochmius duodenalis, uncinaria americana, necator americanus, and belonging to the nematode family Strongylidæ (Stiles). It was formerly thought that the larvæ of the uncinaria found entrance by the mouth in food or water, but it is now known, through the observations and experiments of Looss, Schaudinn, Sandwith and Smith, and others that a common mode of entrance is by way of the skin of the lower extremities in those going barefooted in moist or wet, muddy and sandy soil, the eggs of the parasites finding their way here in the alvine discharges from affected persons. The cutaneous disturbance begins commonly as reddish spots or macules which soon show papulation or vesicles; the latter may coalesce and form small and large blebs, which rupture and expose raw, oozing surface, and often with considerable underlying swelling of the parts. In some instances there is a tendency to pustulation, and even sometimes to the development of ulceration. The eruption, which is usually

1 Recent literature of Ground itch: Stiles, "The Significance of the Hookworm Disease for the Texas Practitioner," Trans. State Med. Assoc. of Texas, 1903, p. 353 (an excellent, clear, and complete exposition and review); C. A. Smith, "Remarks on the Mode of Infection in Uncinariasis," Jour. Amer. Med. Assoc., 1905, vol. xlv., p. 1142 and ibid., 1906, vol. xlvii., p. 1693; Leonard, "Ankylostomiasis or Uncinariasis," Jour. Amer. Med. Assoc., 1905, vol. xlv., p. 588; Dubreuilh, "L'Ankylostomiase Cutanée," La Presse Med., Apr. 15, 1905; Ashford, "The Problem of Epidemic Uncinariasis in Porto Rico," Jour. Assoc. of Military Surgeons, Jan. 1907, p. 40. These various papers refer to the observations of Looss, Sandwith, Bently, and others. Cole, "Necator Americanus in Natives of the Philippines," Philippine Jour. of Sci., Manila, Aug., 1907.

intensely itchy, is frequently first observed between the toes.

It may be limited to a part of one foot or may involve both extensively; the toes and lateral parts are the favorite localities. With good management the cutaneous disturbance subsides in a few weeks, but in those cases in which scratching and secondary coccic infection occur, the eruption lasts much longer and may extend somewhat beyond its usual regional limit, and occasionally lead to obstinate ulcerations, and exceptionally to gangrene. It is not uncommon for a person to have several attacks, each due to exposure to a fresh invasion of the larvæ.

The treatment of the cutaneous irritation consists in cleanliness, the use of mild antiseptic lotions and ointments, such as are used in the acute types of eczema and other types of acute dermatitis; the opening of vesicles, blebs, and pustules, and their cleansing and disinfection. Long soaking of the parts in antiseptic solution, such as boric acid solution and weak corrosive sublimate lotions, is commended. The avoidance of going barefooted in the warm, rainy season is a positive preventive measure. It is thought by some observers that in some of the cases of so-called ground itch the malady may be due to bacterial infection other than that of the hookworm larvæ.

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66

Trypanosomiasis, in its advanced stages known as sleeping sickness," results from the invasion of the body by a minute flagellate parasite through the intermediary of a certain insect, belonging probably to the species glossina palpalis. There is usually a variable irritation at the points of cutaneous puncture made by the insect, through which the trypanosome gains entrance to the body; and later at the point or points of irritation there may arise a red or violaceous, furunculoid, slightly elevated swelling. After several days these formations may have disappeared, leaving behind pigmented spots which gradually fade away. In other instances the reaction may be more intense, sometimes with markedly inflammatory symptoms and edema. Apparently suppuration does not occur. In these more violent cases there is considerable constitutional disturbance, with lymphangitis and adenitis. The nucha, limbs, knees, flanks, and axillary regions are the favorite sites. Later, when the systemic malady is developed, the eruptive phenomena may consist of itchy vesicopapular lesions, polymorphous urticarial erythemas, and the more or less diagnostic polymorphic erythemas, which assume the type of erythema circinata, the ring-like patches being sometimes several inches or more in diameter. The constitutional involvement gradually becomes severe, anemia, nervous and other like symptoms present, with mental and physical lassitude, and the patient may succumb. The malady was for a time thought to be more or less limited to the dark race in portions of Africa, but is now known to occur elsewhere, and also among the whites. In the treatment much stress has been placed on arsenic. Prophylaxis is, however, the important part in the control of the malady, protection from insects, etc. For the cutaneous symptoms, antiparasitic and mildly antiseptic lotions may be employed when required.

1 Some recent literature: Manson, "Tropical Diseases"; Rogers, "Fevers in the Tropics," 1908; and Darré, "Les symptomes cutanés de la trypanosomiase humaine," Annales, 1908, p. 673 (review, with many references).

SUPPLEMENTARY SECTION

FOR PRESENTATION OF A FEW DISEASES OF THE ADJOINING MUCOUS MEMBRANES NOT ELSEWHERE CONSIDERED.

THE mucous membranes in proximity to and adjoining the skin are quite frequently the subject of diseases corresponding to, and existing conjointly with, those of the latter. These have, to a great extent, been already referred to in connection with the individual cutaneous maladies, such as eczema, lichen planus, pemphigus, erythema multiforme, lupus vulgaris, syphilis, and others. It is the purpose to describe here briefly several other affections of the tongue, vermilion of the lips, and contiguous mucous membrane which come from time to time under dermatologic inspection. For other diseases of the tongue and oral cavity the reader is referred to special works on the subject.1

LEUKOPLAKIA.

Synonyms.-Leukoplakia buccalis; Leukokeratosis buccalis; Leukoma; Leukoplasia; Ichthyosis linguæ; Tylosis linguæ ; Psoriasis of the tongue ;

FIG. 280.-Leukoplakia, of slight development, chiefly short streaks and small spots, in a man aged fifty, of several years' duration; also a pale, somewhat diffused, milky color of the main portion of the tongue, and some furrowing; contracted syphilis when aged thirty-five, but has had no manifestations for years.

Smokers' patches; Chronic superficial glossitis; Fr., Leucoplasie; Plaques opalines; Plaques blanches des fumeurs; Plaques blanches de la bouche.

1 Fordyce, "Some Affections of the Oral and Nasal Cavities which Are Related to Skin Diseases," New York Med. Jour., Mar. 6, 1909, p. 465, gives a serial review of these and other various conditions showing mucous membrane involvement.

2 See the admirable and largely illustrated monographs by Butlin and Spencer, Diseases of the Tongue, Cassell and Company; and Mikulicz and Kümmel, Die Krankheiten des Mundes, Jena.

Definition. A disease of the mucous membrane of the buccal cavity, commonly of the tongue, characterized by one, several, or more rounded, irregularly shaped or diffused, whitish patches, often more or less thickened, with sometimes a tendency to fissure. Although this not infrequent malady was occasionally alluded to in older writings, Bazin (1866) and his pupil Debove were the first to give a clear description, followed by the classic presentation by Schwimmer,' Vidal,' Leloir,3 Besnier and Doyon. These and other contributions have firmly established the individuality of the affection, and demonstrated that it is not necessarily a manifestation of psoriasis or a symptom or consequence of syphilis, but that it may often arise and exist independently of these and other maladies.

Symptoms. The earliest evidence of a leukoplakia patch is a slightly increased redness, sometimes with a bluish tinge, which is often so trifling as to be recognizable only on close inspection. Sometimes it has a somewhat thinned or abraded look. Occasionally there is also a scarcely perceptible accentuation of the papillæ, peripherally as well as less commonly on the surface of the spot

FIG. 281.-Leukoplakia of extensive development, in a man aged forty-five, and of eight years' duration; has been subject of psoriasis for twelve years; never had syphilis (Schwimmer).

itself. At this time there is often some sensitiveness to hot and acid foods. This stage of the malady, which lasts a variable time of weeks or months, frequently escapes observation, the first sign recognized being the white or opaline spot into which it slowly evolves. This consists of a rounded, ovalish, or irregularly shaped patch of a faint pearly, bluish-white, or pale milk color,

1 Schwimmer, Archiv, 1877, p. 511 (with review of the subject, references, and 4 colored case illustrations).

2 Vidal, Union méd., vol. xxxv., 1883, pp. 1 and 37.

3 Leloir, Arch. de Physiolog., vol. x., 1887, p. 86 (with 6 colored histologic illustra

tions).