Arthropoda

Leptus autumnalis (Grass, Harvest, or Gooseberry Mite).

In the hot season of the year, that is, during the months of July and August, it is noticed that those people who stray amongst syringa bushes or who pick gooseberries or kidney beans are attacked by the Leptus autumnalis. On the uncovered parts of the body there appear numerous red spots and papules, which itch and burn smartly. The itching does not commence diffusely, as in the case of scabies (MacLennars), but is limited to the particular points where the parasite is situated. There are especial outbreaks of itching in the morning, arising perhaps from the hatching of ova in the host after lying in the warmth of the bed. Leptus frequently provokes general erythema, eczematization or severe feverish urticaria, which in France is known by the name of fièvre de grain (Mégnieu, Besnier). If the individual efflorescences be carefully examined, there will be noticed almost without exception a minute boss towards the centre, noticeable by its yellowish-red colour. If an attempt is made to remove it with the point of a needle or to scrape it off the surface, one can often perceive, even with the naked eye, a small reddish creature moving actively about. The treatment of these very troublesome symptoms consists in warm baths with soapy lavages, also lavages with alcohol, spirit salmiac (G. P.), 5 per cent. carbol or creolin solution, diluted vinegar, benzine, emulsions of balsam of Peru, rubbing in sulphur ointment (Sandwith); ointments of creosote or eucalyptus are recommended. Other grass and grain mites also occasionally penetrate the skin of man and produce transitory but sometimes very severe eruptions, urticaria and eczema papulosum, as Geber and subsequent to him Josai have reported of the barley mite. In sensitive individuals the skin becomes bright red, to a greater or less extent their temperature is raised and frequently slight febrile affections are present. If the inflammatory skin symptoms have reached their culminating point after three or four days and no fresh complications arise, they only remain for a short while, the effects of scratching and pigment spots being left.

Kedani, Akaneesch (The Japanese River or Inundation Disease).

This disease is only known in Japan, and is limited to the neighbourhood of some great rivers on the west coast. The people mostly attacked are those who cut the hemp harvest in the infected localities, occasionally those who transport it or come into contact with it (Looss). The disease is frequently manifested in the form of indefinite disturbances of the general condition; it commences generally on the sixth day after the presumed infection with rigors, headaches, feeling of weakness, swelling of the lymphatic glands in the loin or in the arm-pits; in the periphery a black dry scab is formed. In addition there is an intense conjunctivitis, and added to symptoms of fever an exanthema resembling measles that lasts from four to seven days. There is frequent delirium and difficulty of hearing which persist for a long while. Obstinate constipation is a striking symptom. At the end of a fortnight, earlier in slighter cases, the fever commences to abate and a rapid convalescence sets in. In pregnant women abortion with fatal issue is frequent. With regard to prophylaxis, Baelz recommends as rapid a cultivation of the soil as possible, which has led to a speedy disappearance of the disease in districts where it was once dreaded. Treatment is symptomatic. Japanese do not tolerate antipyretic drugs as well as Europeans.

Dermanyssus gallinæ (avium).

During the day the resort of bird mites is in the droppings and in the woodwork, etc., of cages in which canaries, crossbills and parrots are kept; in the crevices of doors, in the chinks between the board planks of bedsteads, so that at night they may seek some domestic animal to suck the blood and so satisfy their hunger. It is by no means rare for young animals, chickens and unfledged pigeons, etc., to perish in consequence of the great loss of blood. This nocturnal habit of life explains why no mites can be found during the day in spite of the most careful examination of the human body, to which they may be transmitted. On the uncovered parts of the body they not only cause severe irritation, but also severe diffuse itching erythema and eczema. Thorough disinfection of the cages by hot solution of caustic potash, in addition, sprinkling over with tar, red carbolic acid or petroleum, thoroughly powdering over the birds with flores pyrethræ, washing with water containing oleum anisi, washing the walls, doors and bedsteads with soap, disinfection of the mattresses, linen and clothes, will protect against further infection. In the case of man the disease needs no special treatment, as the eruptions generally disappear after some days. Heinecke recommends lavages with 1 per cent. carbolic acid solution. [Vide also p. 492 in body of this work.—F. V. T.]

[Dermanyssus hirundinis, Hermann, is identical with this species. By far the best treatment is with paraffin or kerosene oil applied to the places where they pass the day.—F. V. T.]

Ixodes reduvius (ricinus).

The female is occasionally transmitted to the human skin, and bores its proboscis deep into it and sucks itself full of blood. At sensitive points of the cutaneous surface—for example over the skin of the penis—a feeling of severe pain is produced. Buy’s observations as to the geographical distribution of the Ixodinæ show that in all lands in which cattle, horses, sheep and dogs exist, Ixodinæ are to be found. Recent observations show that the Ixodinæ play an important part in the transmission of Hæmosporidia (vide body of work, pp. 493, 494). Sprinkling with oil, vaseline, benzine, ether, petroleum, naphtha, turpentine (Jelgenum), will easily lead to the removal of the parasite; if the body is torn away with violence and the proboscis is left sticking in the skin, the presence of the latter will give rise to inflammation and suppuration.

Sarcoptes scabiei (Scabies).

The disease produced by Sarcoptes scabiei shows itself in polymorphous areas, such as accompany eczema, and are produced on the one hand by the Sarcoptes alone and on the other hand by the scratching with the nails. The localization of both kinds of efflorescences is different from those which are produced by the Sarcoptes; they occur as papules, vesicles, pustules and mite-tracks, and their usual situation is between the fingers, on the ulnar border of the hand, on the wrist, on the palm of the hand, on the anterior border of the axilla, on the penis and at the base of the thorax. The excoriations are situated on the forearm, over the thigh, over the abdomen, and may be distributed in greater or less degree over the whole body; the back and the face only remain free. The symptoms consist in violent itching, the onset of which specially takes place at night.

The mite-tracks are fine curving lines, curved like a, u, c, or s, which appear as if they had been scratched with a fine needle. Upon closer examination with the magnifying glass one sees in their course small openings. These openings, in persons who keep themselves clean, are scarcely coloured; but in patients whose occupations necessitate their being associated with coloured or dirty substances, they are dark. The length of the tracks varies from some millimetres to 1 1/2 to 2 cm. They are at the one end, where the Sarcoptes is embedded in the epidermis, widened like a funnel and slightly exfoliated. The track at this point is sharply defined; the mite shows through the epidermis as a yellowish round point. In the course of the track there develop papulæ, vesicles or pustules, which raise the level of the track. The intensity of these inflammatory appearances depends upon the susceptibility of the human individual and upon the capability of the reaction of the skin. There are people in whom scarcely any inflammatory symptoms make their appearance; on the other hand there are some, especially children and lymphatic individuals, in whom severe impetiginous ecthymatous pustules, together with their sequelæ, are set up.

The results produced by scratching consist in papules, which usually bear a small scab of blood, and are arranged in the form of striæ, in eczematous surfaces, weeping or sanguineous scabs, vesicles, pustules, etc. The complications that set in are frequently urticaria and even furuncles, lymphangitis and inflammation of the glands, which now and then is followed by the formation of abscesses in the glands.

The duration of the disease is unlimited; when untreated it leads to a form of rare occurrence, that of scabies norvegica; in this the collection of crusts and scales, in which a quantity of dead mites, larvæ and ova are present, may become colossal.

The symptoms of scabies abate in the presence of intercurrent acute diseases and reappear after the malady is over. The fact has for long contributed to the idea of scabies being regarded as a disease capable of being “driven in” upon the internal organs and forming metastases.

The diagnosis is rendered certain upon the discovery of a track. Traces of scratching on the extremities and on the abdomen, papular or pustular efflorescences between the fingers, toes, in the neighbourhood of the wrist, of the elbow, on the anterior border of the arm-pit, on the tuber ischii, in the girdle region, and especially the presence of disintegrated tracts over the penis (prepuce and glans), will allow of the diagnosis being made. Certain occupational eczemas (grocers, lime-workers, maltsters, bakers and others), also prurigo, must be borne in mind when diagnosing this disease.

The prognosis is always a favourable one. Even after such a long duration and after such severe symptoms the disease may completely clear up. There are, however, frequently left behind post-scabious inflammatous and pruriginous conditions which only yield after protracted treatment. Scabiophilia, which persists in certain patients for a long time after the scabies has been cured, must here be mentioned.

In the treatment of scabies four points must be kept in view. (1) The mites and the ova must be killed by the treatment; (2) the treatment must have regard to the intensity of the inflammatory symptoms; (3) the clothes (body-linen) of the patients must be disinfected; the bed-linen, the beds and the bedsteads must be cleansed; (4) when a person suffers from scabies his entourage must be examined, and all diseased conditions treated in the same way as under (3).

The treatment (1) should be preceded by a bath with thorough soap ablution, and when the inflammatory symptoms are not too severe, with green soap. After the bath the skin is dried and the scabies remedy proper applied in warmth. Sulphur preparations receive first consideration; among such Vlemingkz’s mixture occupies a prominent position; this is rubbed in for half an hour by means of a strong camel-hair brush, to be followed by another bath and powder applications after drying. Repeat this method for three days one after the other, or for two days, and a third time eight days later. The latter method is worthy of recommendation as the ova, which perhaps resist the parasiticide action, have by this time developed into larvæ, and the latter can then be destroyed with certainty. The remaining sulphur preparations, which are specially employed in the form of ointments, are more complex, as the ointment should remain on the skin. Helmerisch’s and Wilkinson’s ointments are the kinds specially employed. Nagelschmidt recommends thiopinol as a very suitable sulphur preparation in the form of baths or as a 10 or 5 per cent. ointment in the following way: Upon his reception the patient is given a thiopinol bath, in which he remains for thirty minutes. Immediately afterwards 30 to 40 grm. 10 per cent. thiopinol vaseline is carefully rubbed in. The rubbing is repeated daily, and the treatment is concluded on the second to fourth day with a second thiopinol bath. Thiopinol produces no more irritation than the ordinary sulphur ointments; it is, however, much more penetrative and more capable of absorption.

We frequently make use of Kaposi’s naphthol ointment, as it renders the skin supple, causes proportionately little irritation, and has but little smell. Treatment with balsam of Peru is certainly expensive, but in the slighter attacks it is relatively the simplest. We give the patient a bath, have him thoroughly dried and rub in 30 to 40 to 50 grm. balsam of Peru carefully and evenly all over, wrap him in a covering of wool, and make him rest in bed for twelve to fifteen hours, to be followed by a bath with careful cleansing with soap; this treatment need rarely be repeated. The balsam of Peru can be applied undiluted for the rubbings or mixed with ung. glycerini, or resorbin or glycerine in equal parts. [Norman Walker uses balsam of Peru 1/2 oz. dissolved in rectified spirit; to be painted on with a brush.]—J. P. S. The manufacturers name the undiluted product of the active constituent of balsam of Peru, benzoic acid benzyl-ester, Peruscabin. For the treatment of scabies it is recommended by Sachs that it should only be administered when mixed with ricinus oil, under the name of Peru oil, in applications repeated three times within thirty-six hours.

Sack also considers Peru oil a non-irritant, effectual, pleasant, inodorous and non-staining drug. But he only allows the applications to be used every twelve hours for three to four consecutive days (altogether 200 to 300 grm. of Peru oil are requisite), and after the sixth or seventh rubbing a bath should be taken with the use of Dutch soap. Juliusberg considers this treatment specially suited for private practice. Another modern drug is epicarin ([Beta]-oxy-naphthyl-ortho-oxy-meta-tolyol acid); this is applied in 10 to 20 per cent. ointments (Pfeiffenberger), epicarin 7·0 grm., cretæ alb. 2·0 grm., vasel. flavi 30·0 grm., lanolin 15·0 grm., axungia poric. 45·0 grm. (Rille); epicarin 15·0 grm., sapon. virid. 5·0 grm., axung. poric. 100·0 grm., cretæ alb. 10·0 grm. (Kraus); for children, epicarin 5·0 grm., lanolin 90·0 grm., ol. olivar. 10·0 grm. (Kaposi). Siebert lays stress upon the odourlessness and colourlessness of epicarin ointment as a strong reason for its use, and points out that it is a harmless drug, the action of which is certain. Endermol (salicylic acid ointment) has a destructive action on the mites even in a 0·1 per cent. ointment (Wolters, Demitsch); it is, however, very expensive and not wholly free from danger; and the same applies to nicotiana soap (Taenzer, Schumann).

To give an account in detail of the drugs and methods—old and new—used in the treatment of scabies would far outrun the limits of this work.

Demodex folliculorum.

It is not yet certain whether the Demodex folliculorum is capable of developing pathological conditions in man. Veiel assumes that the hair follicle mite has no connection either with the formation of comedones or even with sebaceous gland disease. Kaposi considers that they cause no disease in man and cannot be regarded as a cause of acne. Saalfeld clearly adheres to the same standpoint, similarly so Jessner, who, when discussing comedones, makes no mention of acne of hair follicle mites. Weyl and Geber adhere to the opinion that the presence of a Demodex in man in contradistinction to its presence in animals possesses absolutely no pathogenic influence. On the other hand de Amicis, Majochi, and Dubreuilh report single cases of pronounced circumscribed clear brown pigmentations which they attribute to Demodex folliculorum. In all these cases, moreover, as regards localization the affection had a certain resemblance to pityriasis versicolor; nevertheless, in the scales separated off with the scalpel no fungi were found, but on the other hand Demodices in moderate quantity. In his earlier cases Majochi has seen the Demodex in the secretion from meibomian glands and had claimed it to be the excitant of chalazion and, as Mibelli did, considered it to be the cause of some diseases of the eyelids. Ivers found the parasite in 69 per cent. of normal borders of the eyelids, and attributes a pathological signification to it. Hünsche and Mulder arrive at the same conclusions; in the light of their investigations the Demodex is found as a constant accessory—certainly not in the meibomian glands, as it is limited only to the internal part of the hair follicle. Lewandowsky considers that it can hardly be demonstrated at present that the same parasite which in individual specimens causes no symptoms is capable of producing pathological conditions when markedly increased in numbers.

Treatment is by the removal of the comedones, above all, by their mechanical removal by pressure with a watch-key and with the various comedo-compressors, and by subsequent cleansing of the skin with ether, benzine or spirit. If the eyelids should be affected with blepharitis due to the presence of Demodex in large numbers, epilation and administration of a parasiticide is recommended.

Demodex folliculorum canis.

Transmission from dog to man is in any case very rare, and by many its occurrence is generally doubted. Nevertheless Gruby and Remak claim that it is transmissible—an opinion which has also been shared by Neumann and Zürn. The latter saw in the case of a married couple who had the care of mangy dogs the onset of diseased areas on their hands and feet, which were like those on the dogs and contained the same parasites.

A. Babes also reports several observations which go to show that persons who, to some extent, have been shown to have been in contact with mange-stricken dogs have been attacked by a scabies-like eruption localized over the thorax, abdomen, back and extremities; large numbers of Demodices were found in the follicular pustules. Lewandowsky reports one case—that of an Italian workman, who suffered from an outbreak on the face, like impetigo; there was crust formation and at the edge of the crusts the epidermis appeared like a narrow row or border of vesicles. A small portion of the covering of the row of vesicles was lifted off, and after slight warming examined in 40 per cent. liquor potassæ. In this a large number of animal parasites of the Demodex group were found, and without doubt Demodex folliculorum canis alone. Hünsche assumes that Demodex folliculorum penetrates into the tissues and produces abscesses.

Treatment first consisted in dusting with zinc amyl powder, but after four days there was no change. After the regular use of xeroform as a powder application, the affection cleared up within fourteen days.