Fig. 27.—Bacillus of Anthrax in section of skin, from a case of malignant pustule; shows vesicle containing bacilli. × 400 diam. Gram's stain.Fig. 27.—Bacillus of Anthrax in section of skin, from a case of malignant pustule; shows vesicle containing bacilli. × 400 diam. Gram's stain.
Fig. 27.—Bacillus of Anthrax in section of skin, from a case of malignant pustule; shows vesicle containing bacilli. × 400 diam. Gram's stain.
Clinical Varieties of Anthrax.—In man, anthrax may manifest itself in one of three clinical forms.
It may be transmitted by means of spores or bacilli directly from a diseased animal to those who, by their occupation or otherwise, are brought into contact with it—for example, shepherds, butchers, veterinary surgeons, or hide-porters. Infection may occur on the face by the use of a shaving-brush contaminated by spores. The path of infection is usually through an abrasion of the skin, and the primary manifestations are local, constituting what is known asthe malignant pustule.
In other cases the disease is contracted through the inhalation of the dried spores into the respiratory passages. This occurs oftenest in those who work amongst wool, fur, and rags, and a form of acute pneumonia of great virulence ensues. This affection is known aswool-sorter's disease, and is almost universally fatal.
There is reason to believe that infection may also take place by means of spores ingested into the alimentary canal in meat or milk derived from diseased animals, or in infected water.
Clinical Features of Malignant Pustule.—We shall here confine ourselves to the consideration of the local lesion as it occurs in the skin—the malignant pustule.
The point of infection is usually on an uncovered part of the body, such as the face, hands, arms, or back of the neck, and the wound may be exceedingly minute. After an incubation period varying from a few hours to several days, a reddish nodule resembling a small boil appears at the seat of inoculation, the immediately surrounding skin becomes swollen and indurated, and over the indurated area there appear a number of small vesicles containing serum, which at first is clear but soon becomes blood-stained (Fig. 28). Coincidently the subcutaneous tissue for a considerable distance around becomes markedly œdematous, and the skin red and tense. Within a few hours, blood is extravasated in the centre of the indurated area, the blisters burst, and a dark brown or black eschar, composed of necrosed skin and subcutaneous tissue and altered blood, forms (Fig. 29). Meanwhile the induration extends, fresh vesicles form and in turn burst, and the eschar increases in size. The neighbouring lymph glands soon become swollen and tender. The affected part is hot and itchy, but the patient does not complain of great pain. There is a moderate degree of constitutional disturbance, with headache, nausea, and sometimes shivering.
If the infection becomes generalised—anthracæmia—the temperature rises to 103° or 104° F., the pulse becomes feeble and rapid, and other signs of severe blood-poisoning appear: vomiting, diarrhœa, pains in the limbs, headache and delirium, and the condition proves fatal in from five to eight days.
Differential Diagnosis.—When the malignant pustule is fully developed, the central slough with the surrounding vesicles and the widespread œdema are characteristic. The bacillus can be obtained from the peripheral portion of the slough, from the blisters, and from the adjacent lymph vessels and glands. The occupation of the patient may suggest the possibility of anthrax infection.
Fig. 28.—Malignant Pustule, third day after infection with Anthrax, showing great œdema of upper extremity and pectoral region (cf. Fig. 29).Fig. 28.—Malignant Pustule, third day after infection with Anthrax, showing great œdema of upper extremity and pectoral region (cf.Fig. 29).
Fig. 28.—Malignant Pustule, third day after infection with Anthrax, showing great œdema of upper extremity and pectoral region (cf.Fig. 29).
Fig. 29.—Malignant Pustule, fourteen days after infection, showing black eschar in process of separation. The œdema has largely disappeared. Treated by Sclavo's serum (cf. Fig. 28).Fig. 29.—Malignant Pustule, fourteen days after infection, showing black eschar in process of separation. The œdema has largely disappeared. Treated by Sclavo's serum (cf.Fig. 28).
Fig. 29.—Malignant Pustule, fourteen days after infection, showing black eschar in process of separation. The œdema has largely disappeared. Treated by Sclavo's serum (cf.Fig. 28).
Prophylaxis.—Any wound suspected of being infected with anthrax should at once be cauterised with caustic potash, the actual cautery, or pure carbolic acid.
Treatment.—The best results hitherto obtained have followed the use of the anti-anthrax serum introduced by Sclavo. The initial dose is 40 c.c., and if the serum is given early in the disease, the beneficial effects are manifest in a few hours. Favourable results have also followed the use of pyocyanase, a vaccine prepared from the bacillus pyocyaneus.
By some it is recommended that the local lesion should be freely excised; others advocate cauterisation of the affected part with solid caustic potash till all the indurated area is softened. Gräf has had excellent results by the latter method in a large series of cases, the œdema subsiding in about twenty-four hours and the constitutional symptoms rapidly improving. Wolff and Wiewiorowski, on the other hand, have had equally good results by simply protecting the local lesion with a mild antiseptic dressing, and relying upon general treatment.
The general treatment consists in feeding and stimulating the patient as freely as possible. Quinine, in 5 to 10Â grain doses every four hours, and powdered ipecacuanha, in 40 to 60Â grain doses every four hours, have also been employed with apparent benefit.
Glanders is due to the action of a specific bacterium, thebacillus mallei, which resembles the tubercle bacillus, save that it is somewhat shorter and broader, and does not stain by Gram's method. It requires higher temperatures for its cultivation than the tubercle bacillus, and its growth on potato is of a characteristic chocolate-brown colour, with a greenish-yellow ring at the margin of the growth. The bacillus mallei retains its vitality for long periods under ordinary conditions, but is readily killed by heat and chemical agents. It does not form spores.
Clinical Features.—Both in the lower animals and in man the bacillus gives rise to two distinct types of disease—acute glanders, andchronic glandersorfarcy.
Acute Glanders is most commonly met with in the horse and in other equine animals, horned cattle being immune. It affects the septum of the nose and adjacent parts, firm, translucent, greyish nodules containing lymphoid and epithelioid cells appearing in the mucous membrane. These nodulessubsequently break down in the centre, forming irregular ulcers, which are attended with profuse discharge, and marked inflammatory swelling. The cervical lymph glands, as well as the lungs, spleen, and liver, may be the seat of secondary nodules.
In man, acute glanders is commoner than the chronic variety. Infection always takes place through an abraded surface, and usually on one of the uncovered parts of the body—most commonly the skin of the hands, arms, or face; or on the mucous membrane of the mouth, nose, or eye. The disease has been acquired by accidental inoculation in the course of experimental investigations in the laboratory, and proved fatal. The incubation period is from three to five days.
Thelocalmanifestations are pain and swelling in the region of the infected wound, with inflammatory redness around it and along the lines of the superficial lymphatics. In the course of a week, small, firm nodules appear, and are rapidly transformed into pustules. These may occur on the face and in the vicinity of joints, and may be mistaken for the eruption of small-pox.
After breaking down, these pustules give rise to irregular ulcers, which by their confluence lead to extensive destruction of skin. Sometimes the nasal mucous membrane becomes affected, and produces a discharge—at first watery, but later sanious and purulent. Necrosis of the bones of the nose may take place, in which case the discharge becomes peculiarly offensive. In nearly every case metastatic abscesses form in different parts of the body, such as the lungs, joints, or muscles.
During the development of the disease the patient feels ill, complains of headache and pains in the limbs, the temperature rises to 104° or even to 106° F., and assumes a pyæmic type. The pulse becomes rapid and weak. The tongue is dry and brown. There is profuse sweating, albuminuria, and often insomnia with delirium. Death may take place within a week, but more frequently occurs during the second or third week.
Differential Diagnosis.—There is nothing characteristic in the site of the primary lesion in man, and the condition may, during the early stages, be mistaken for a boil or carbuncle, or for any acute inflammatory condition. Later, the disease may simulate acute articular rheumatism, or may manifest all the symptoms of acute septicæmia or pyæmia. The diagnosis is established by the recognition of the bacillus. Veterinarysurgeons attach great importance to the mallein test as a means of diagnosis in animals, but in the human subject its use is attended with considerable risk and is not to be recommended.
Treatment.—Excision of the primary nodule, followed by the application of the thermo-cautery and sponging with pure carbolic acid, should be carried out, provided the condition is sufficiently limited to render complete removal practicable.
When secondary abscesses form in accessible situations, they must be incised, disinfected, and drained. The general treatment is carried out on the same lines as in other acute infective diseases.
Chronic Glanders.—In the horsethe chronic form of glanders is known asfarcy, and follows infection through an abrasion of the skin, involving chiefly the superficial lymph vessels and glands. The lymphatics become indurated and nodular, constituting what veterinarians callfarcy pipesandfarcy buds.
In manalso the clinical features of the chronic variety of the disease are somewhat different from those of the acute form. Here, too, infection takes place through a broken cutaneous surface, and leads to a superficial lymphangitis with nodular thickening of the lymphatics (farcy buds). The neighbouring glands soon become swollen and indurated. The primary lesion meanwhile inflames, suppurates, and, after breaking down, leaves a large, irregular ulcer with thickened edges and a foul, purulent or bloody discharge. The glands break down in the same way, and lead to wide destruction of skin, and the resulting sinuses and ulcers are exceedingly intractable. Secondary deposits in the subcutaneous tissue, the muscles, and other parts, are not uncommon, and the nasal mucous membrane may become involved. The disease often runs a chronic course, extending to four or five months, or even longer. Recovery takes place in about 50Â per cent. of cases, but the convalescence is prolonged, and at any time the disease may assume the characters of the acute variety and speedily prove fatal.
Thedifferential diagnosisis often difficult, especially in the chronic nodules, in which it may be impossible to demonstrate the bacillus. The ulcerated lesions of farcy have to be distinguished from those of tubercle, syphilis, and other forms of infective granuloma.
Treatment.—Limited areas of disease should be completely excised. The general condition of the patient must be improved by tonics, good food, and favourable hygienic surroundings. In some cases potassium iodide acts beneficially.
Actinomycosis is a chronic disease due to the action of an organism somewhat higher in the vegetable scale than ordinary bacteria—thestreptothrix actinomycesorray fungus.
Fig. 30.—Section of Actinomycosis Colony in Pus from Abscess of Liver, showing filaments and clubs of streptothrix actinomyces. × 400 diam. Gram's stain.Fig. 30.—Section of Actinomycosis Colony in Pus from Abscess of Liver, showing filaments and clubs of streptothrix actinomyces. × 400 diam. Gram's stain.
Fig. 30.—Section of Actinomycosis Colony in Pus from Abscess of Liver, showing filaments and clubs of streptothrix actinomyces. × 400 diam. Gram's stain.
Etiology and Morbid Anatomy.—The actinomyces, which has never been met with outside the body, gives rise in oxen, horses, and other animals to tumour-like masses composed of granulation tissue; and in man to chronic suppurative processes which may result in a condition resembling chronic pyæmia. The actinomyces is more complex in structure than other pathogenic organisms, and occurs in the tissues in the form of small, round, semi-translucent bodies, about the size of a pin-head or less, and consisting of colonies of the fungus. On account of their yellow tint they are spoken of as “sulphur grains.†Each colony is made up of a series of thin, interlacing, and branchingfilaments, some of which are broken up so as to form masses or chains ofcocci; and around the periphery of the colony are elongated, pear-shaped, hyaline,club-like bodies(Fig. 30).
Infection is believed to be conveyed by the husks of cereals, especially barley; and the organism has been found adhering to particles of grain embedded in the tissues of animals suffering from the disease. In the human subject there is often a history of exposure to infection from such sources, and the disease is said to be most common during the harvesting months.
Around each colony of actinomyces is a zone of granulation tissue in which suppuration usually occurs, so that the fungus comes to lie in a bath of greenish-yellow pus. As the process spreads these purulent foci become confluent and form abscess cavities. When metastasis takes place, as it occasionally does, the fungus is transmitted by the blood vessels, as in pyæmia.
Clinical features.—In man the disease may be met with in the skin, the organisms gaining access through an abrasion, and spreading by the formation of new nodules in the same way as tuberculosis.
The region of the mouth and jaws is one of the commonest sites of surgical actinomycosis. Infection takes place, as a rule, along the side of a carious tooth, and spreads to the lower jaw. A swelling is slowly and insidiously developed, but when the loose connective tissue of the neck becomes infiltrated, the spread is more rapid. The whole region becomes infiltrated and swollen, and the skin ultimately gives way and free suppuration occurs, resulting in the formation of sinuses. The characteristic greenish-grey or yellow granules are seen in the pus, and when examined microscopically reveal the colonies of actinomyces.
Less frequently the maxilla becomes affected, and the disease may spread to the base of the skull and brain. The vertebræ may become involved by infection taking place through the pharynx or œsophagus, and leading to a condition simulating tuberculous disease of the spine. When it implicates the intestinal canal and its accessory glands, the lungs, pleura, and bronchial tubes, or the brain, the disease is not amenable to surgical treatment.
Differential Diagnosis.—The conditions likely to be mistaken for surgical actinomycosis are sarcoma, tubercle, and syphilis. In the early stages the differential diagnosis is exceedingly difficult. In many cases it is only possible when suppuration has occurred and the fungus can be demonstrated.
The slow destruction of the affected tissue by suppuration, the absence of pain, tenderness, and redness, simulate tuberculosis, but the absence of glandular involvement helps to distinguish it.
Syphilitic lesions are liable to be mistaken for actinomycosis, all the more that in both diseases improvement follows the administration of iodides. When it affects the lower jaw, in its early stages, actinomycosis may closely simulate a periosteal sarcoma.
Fig. 31.—Actinomycosis of Maxilla. The disease spread to opposite side; finally implicated base of skull, and proved fatal. Treated by radium. (Mr. D.P.D. Wilkie's case.)Fig. 31.—Actinomycosis of Maxilla. The disease spread to opposite side; finally implicated base of skull, and proved fatal. Treated by radium.(Mr. D. P. D. Wilkie's case.)
Fig. 31.—Actinomycosis of Maxilla. The disease spread to opposite side; finally implicated base of skull, and proved fatal. Treated by radium.
(Mr. D. P. D. Wilkie's case.)
The recognition of the fungus is the crucial point in diagnosis.
Prognosis.—Spontaneous cure rarely occurs. When the disease implicates internal organs, it is almost always fatal. On external parts the destructive process gradually spreads, and the patient eventually succumbs to superadded septic infection. When, from its situation, the primary focus admits of removal, the prognosis is more favourable.
Treatment.—The surgical treatment is early and free removal of the affected tissues, after which the wound is cauterised by the actual cautery, and sponged over with pure carbolic acid. The cavity is packed with iodoform gauze, no attempt being made to close the wound.
Success has attended the use of a vaccine prepared from cultures of the organism; and the X-rays and radium, combined with the administration of iodides in large doses, or with intra-muscular injections of a 10Â per cent. solution of cacodylate of soda, have proved of benefit.
Mycetoma, or Madura Foot.—Mycetoma is a chronic disease due to an organism resembling that of actinomycosis, but not identical with it. It is endemic in certain tropical countries, and is most frequently met with in India. Infection takes place through an abrasion of the skin, and the disease usually occurs on the feet of adult males who work barefooted in the fields.
Clinical Features.—The disease begins on the foot as an indurated patch, which becomes discoloured and permeated by black or yellow nodules containing the organism. These nodules break down by suppuration, and numerous minute abscesses lined by granulation tissues are thus formed. In the pus are found yellow particles likened to fish-roe, or black pigmented granules like gunpowder. Sinuses form, and the whole foot becomes greatly swollen and distorted by flattening of the sole and dorsiflexion of the toes. Areas of caries or necrosis occur in the bones, and the disease gradually extends up the leg (Fig. 32). There is but little pain, and no glandular involvement or constitutional disturbance. The disease runs a prolonged course, sometimes lasting for twenty or thirty years. Spontaneous cure never takes place, and the risk to life is that of prolonged suppuration.
If the disease is localised, it may be removed by the knife or sharp spoon, and the part afterwards cauterised. As a rule, amputation well above the disease is the best line of treatment. Unlike actinomycosis, this disease does not appear to be benefited by iodides.
Fig. 32.—Mycetoma, or Madura Foot. (Museum of Royal College of Surgeons, Edinburgh.)Fig. 32.—Mycetoma, or Madura Foot.(Museum of Royal College of Surgeons, Edinburgh.)
Fig. 32.—Mycetoma, or Madura Foot.
(Museum of Royal College of Surgeons, Edinburgh.)
Delhi Boil.—Synonyms—Aleppo boil, Biskra button, Furunculus orientalis, Natal sore.
Delhi boil is a chronic inflammatory disease, most commonly met with in India, especially towards the end of the wet season. The disease occurs oftenest on the face, and is believed to be due to an organism, although this has not been demonstrated. The infection is supposed to be conveyed through water used for washing, or by the bites of insects.
Clinical Features.—A red spot, resembling the mark of a mosquito bite, appears on the affected part, and is attended with itching. After becoming papular and increasing to the size of a pea, desquamation takes place, leaving a dull-red surface, over which in the course of several weeks there develops a series of small yellowish-white spots, from which serumexudes, and, drying, forms a thick scab. Under this scab the skin ulcerates, leaving small oval sores with sharply bevelled edges, and an uneven floor covered with yellow or sanious pus. These sores vary in number from one to forty or fifty. They may last for months and then heal spontaneously, or may continue to spread until arrested by suitable treatment. There is no enlargement of adjacent glands, and but little inflammatory reaction in the surrounding tissues; nor is there any marked constitutional disturbance. Recovery is often followed by cicatricial contraction leading to deformity of the face.
Thetreatmentconsists in destroying the original papule by the actual cautery, acid nitrate of mercury, or pure carbolic acid. The ulcers should be scraped with the sharp spoon, and cauterised.
Chigoe.—Chigoe or jigger results from the introduction of the eggs of the sand-flea (Pulex penetrans) into the tissues. It occurs in tropical Africa, South America, and the West Indies. The impregnated female flea remains attached to the part till the eggs mature, when by their irritation they cause localised inflammation with pustules or vesicles on the surface. Children are most commonly attacked, particularly about the toe-nails and on the scrotum. The treatment consists in picking out the insect with a blunt needle, special care being taken not to break it up. The puncture is then cauterised. The application of essential oils to the feet acts as a preventive.
Poisoning by Insects.—The bites of certain insects, such as mosquitoes, midges, different varieties of flies, wasps, and spiders, may be followed by serious complications. The effects are mainly due to the injection of an irritant acid secretion, the exact nature of which has not been ascertained.
The local lesion is a puncture, surrounded by a zone of hyperæmia, wheals, or vesicles, and is associated with burning sensations and itching which usually pass off in a few hours, but may recur at intervals, especially when the patient is warm in bed. Scratching also reproduces the local signs and symptoms. Where the connective tissue is loose—for example, in the eyelid or scrotum—there is often considerable swelling; and in the mouth and fauces this may lead to œdema of the glottis, which may prove fatal.
Thetreatmentconsists in the local application of dilute alkalies such as ammonia water, solutions of carbonate or bicarbonate of soda, or sal-volatile. Weak carbolic lotions, or lead and opium lotion, are useful in allaying the local irritation. One of the best means of neutralising the poison is to apply to the sting a drop of a mixture containing equal parts of pure carbolic acid and liquor ammoniæ.
Free stimulation is called for when severe constitutional symptoms are present.
Snake-Bites.—We are here only concerned with the injuries inflicted by the venomous varieties of snakes, the most important of which are the hooded snakes of India, the rattle-snakes of America, the horned snakes of Africa, the viper of Europe, and the adder of the United Kingdom.
While the virulence of these creatures varies widely, they are all capable of producing in a greater or less degree symptoms of acute poisoning in man and other animals. By means of two recurved fangs attached to the upper jaw, and connected by a duct with poison-secreting glands, they introduce into their prey a thick, transparent, yellowish fluid, of acid reaction, probably of the nature of an albumose, and known as thevenom.
Theclinical featuresresulting from the injection of the venom vary directly in intensity with the amount of the poison introduced, and the rapidity with which it reaches the circulating blood, being most marked when it immediately enters a large vein. The poison is innocuous when taken into the stomach.
Locallythe snake inflicts a double wound, passing vertically into the subcutaneous tissue; the edges of the punctures are ecchymosed, and the adjacent vessels the seat of thrombosis. Immediately there is intense pain, and considerable swelling with congestion, which tends to spread towards the trunk. Extensive gangrene may ensue. There is no special involvement of the lymphatics.
Thegeneral symptomsmay come on at once if the snake is a particularly venomous one, or not for some hours if less virulent. In the majority of viper or adder bites the constitutional disturbance is slight and transient, if it appears at all. Snake-bites in children are particularly dangerous.
The patient's condition is one of profound shock with faintness, giddiness, dimness of sight, and a feeling of great terror. The pupils dilate, the skin becomes moist with a clammy sweat, and nausea with vomiting, sometimes of blood, ensues. High fever, cramps, loss of sensation, hæmaturia, and melæna are among the other symptoms that may be present. The pulse becomes feeble and rapid, the respiratory nerve centres are profoundly depressed, and delirium followed by coma usually precedes the fatal issue, which may take place in from five to forty-eight hours. If the patient survives for two days the prognosis is favourable.
Treatment.—A broad ligature should be tied tightly round the limb above the seat of infection, to prevent the poison passing into the generalcirculation, and bleeding from the wound should be encouraged. The application of an elastic bandage from above downward to empty the blood out of the infected portion of the limb has been recommended. The whole of the bite should at once be excised, and crystals of permanganate of potash rubbed into the wound until it is black, or peroxide of hydrogen applied with the object of destroying the poison by oxidation.
The general treatment consists in free stimulation with whisky, brandy, ammonia, digitalis, etc. Hypodermic injections of strychnin in doses sufficiently large to produce a slight degree of poisoning by the drug are particularly useful. The most rational treatment, when it is available, is the use of theantiveninintroduced by Fraser and Calmette.
Tuberculosis occurs more frequently in some situations than in others; it is common, for example, in lymph glands, in bones and joints, in the peritoneum, the intestine, the kidney, prostate and testis, and in the skin and subcutaneous cellular tissue; it is seldom met with in the breast or in muscles, and it rarely affects the ovary, the pancreas, the parotid, or the thyreoid.
Tubercle bacillivary widely in their virulence, and they are more tenacious of life than the common pyogenic bacteria. In a dry state, for example, they can retain their vitality for months; and they can also survive immersion in water for prolonged periods. They resist the action of the products of putrefaction for a considerable time, and are not destroyed by digestive processes in the stomach and intestine. They may be killed in a few minutes by boiling, or by exposure to steam under pressure, or by immersion for less than a minute in 1 in 20 carbolic lotion.
Methods of Infection.—In marked contrast to what obtains in the infective diseases that have already been described, tuberculosis rarely results from theinfection of a wound. In exceptional instances, however, this does occur, and in illustration of the fact may be cited the case of a servant who cut her finger with a broken spittoon containing the sputum of her consumptive master; the wound subsequently showed evidence of tuberculous infection, which ultimately spread up along the lymph vessels of the arm. Pathologists, too, whose hands, before the days of rubber gloves, were frequently exposed to the contact of tuberculous tissues and pus, were liable to sufferfrom a form of tuberculosis of the skin of the finger, known asanatomical tubercle. Slight wounds of the feet in children who go about barefoot in towns sometimes become infected with tubercle. Operation wounds made with instruments contaminated with tuberculous material have also been known to become infected. It is highly probable that the common form of tuberculosis of the skin known as “lupus†arises by direct infection from without.
Fig. 33.—Tubercle Bacilli in caseous material × 1000 diam. Z. Neilsen stain.Fig. 33.—Tubercle Bacilli in caseous material × 1000 diam. Z. Neilsen stain.
Fig. 33.—Tubercle Bacilli in caseous material × 1000 diam. Z. Neilsen stain.
In the vast majority of cases the tubercle bacillus gains entrance to the body by way of the mucous surfaces, the organisms being either inhaled or swallowed; those inhaled are mostly derived from the human subject, those swallowed, from cattle. Bacilli, whether inhaled or swallowed, are especially apt to lodge about the pharynx and pass to the pharyngeal lymphoid tissue and tonsils, and by way of the lymph vessels to the glands. The glands most frequently infected in this way arethe cervical glands, and those within the cavity of the chest—particularly the bronchial glands at the root of the lung. From these, infection extends at any later period in life to the bones, joints, and internal organs.
There is reason to believe that the organisms may lie in a dormant condition for an indefinite period in these glands, and only become active long afterwards, when some depression of the patient's health produces conditions which favour their growth. When the organisms become active in this way, the tuberculous tissue undergoes softening and disintegration, and the infective material, by bursting into an adjacent vein, may enter the blood-stream, in which it is carried to distant parts of the body. In this way ageneral tuberculosismay be set up, or localised foci of tuberculosis may develop in the tissues in which the organisms lodge. Many tuberculous patients are to be regarded as possessing in their bronchial glands, or elsewhere, an internal store of bacilli, to which the disease for which advice is sought owes its origin, and from which similar outbreaks of tuberculosis may originate in the future.
The alimentary mucous membrane, especially that of the lower ileum and cæcum, is exposed to infection by swallowed sputum and by food materials, such as milk, containing tubercle bacilli. The organisms may lodge in the mucous membrane and cause tuberculous ulceration, or they may be carried through the wall of the bowel into the lacteals, along which they pass to the mesenteric glands where they become arrested and give rise to tuberculous disease.
Relationship of Tuberculosis to Trauma.—Any tissue whose vitality has been lowered by injury or disease furnishes a favourable nidus for the lodgment and growth of tubercle bacilli. The injury or disease, however, is to be looked upon as determining thelocalisationof the tuberculous lesion rather than as an essential factor in its causation. In a person, for example, in whose blood tubercle bacilli are circulating and reaching every tissue and organ of the body, the occurrence of tuberculous disease in a particular part may be determined by the depression of the tissues resulting from an injury of that part. There can be no doubt that excessive movement and jarring of a limb aggravates tuberculous disease of a joint; also that an injury may light up a focus that has been long quiescent, but we do not agree with those—Da Costa, for example—who maintain that injury may be a determining cause of tuberculosis. The question is not one of mere academic interest, but one that may raise important issues in the law courts.
Human and Bovine Tuberculosis.—The frequency of the bovine bacillus in the abdominal and in the glandular and osseous tuberculous lesions of children would appear to justify the conclusion that the disease is transmissible from the ox to the human subject, and that the milk of tuberculous cows is probably a common vehicle of transmission.
Changes in the Tissues following upon the successful Lodgment of Tubercle Bacilli.—The action of the bacilli on the tissues results in the formation of granulation tissue comprising characteristic tissue elements and with a marked tendency to undergo caseation.
The recognition of the characteristic elements, with or without caseation, is usually sufficient evidence of the tuberculous nature of any portion of tissue examined for diagnostic purposes. The recognition of the bacillus itself by appropriate methods of staining makes the diagnosis a certainty; but as it is by no means easy to identify the organism in many forms of surgical tuberculosis, it may be necessary to have recourse to experimental inoculation of susceptible animals such as guinea-pigs.
The changes subsequent to the formation of tuberculous granulation tissue are liable to many variations. It must always be borne in mind that although the bacilli have effected a lodgment and have inaugurated disease, the relation between them and the tissues remains one of mutual antagonism; which of them is to gain and keep the upper hand in the conflict depends on their relative powers of resistance.
If the tissues prevail, there ensues a process of repair. In the immediate vicinity of the area of infection young connective tissue, and later, fibrous tissue, is formed. This may replace the tuberculous tissue and bring about repair—a fibrous cicatrix remaining to mark the scene of the previous contest. Scars of this nature are frequently discovered at the apex of the lung after death in persons who have at one time suffered from pulmonary phthisis. Under other circumstances, the tuberculous tissue that has undergone caseation, or even calcification, is only encapsulated by the new fibrous tissue, like a foreign body. Although this may be regarded as a victory for the tissues, the cure, if such it may be called, is not necessarily a permanent one, for at any subsequent period, if the part affected is disturbed by injury or through some other influence, the encapsulated tubercle may again become active and get the upper hand of the tissues, and there results a relapse orrecrudescence of the disease. Thistendency to relapseafter apparent cure is a notable feature of tuberculous disease as it is met with in thespine, or in the hip-joint, and it necessitates a prolonged course of treatment to give the best chance of a lasting cure.
If, however, at the inauguration of the tuberculous disease the bacilli prevail, the infection tends to spread into the tissues surrounding those originally infected, and more and more tuberculous granulation tissue is formed. Finally the tuberculous tissue breaks down and liquefies, resulting in the formation of a cold abscess. In their struggle with the tissues, tubercle bacilli receive considerable support and assistance from any pyogenic organisms that may be present. A tuberculous infection may exhibit its aggressive qualities in a more serious manner by sending off detachments of bacilli, which are carried by the lymphatics to the nearest glands, or by the blood-stream to more distant, and it may be to all, parts of the body. When the infection is thus generalised, the condition is calledgeneral tuberculosis. Considering the extraordinary frequency of localised forms of surgical tuberculosis, general dissemination of the disease is rare.
The clinical featuresof surgical tuberculosis will be described with the individual tissues and organs, as they vary widely according to the situation of the lesion.
The general treatmentconsists in combating the adverse influences that have been mentioned as increasing the liability to tuberculous infection. Within recent years the value of the “open-air†treatment has been widely recognised. An open-air life, even in the centre of a city, may be followed by marked improvement, especially in the hospital class of patient, whose home surroundings tend to favour the progress of the disease. The purer air of places away from centres of population is still better; and, according to the idiosyncrasies of the individual patient, mountain air or that of the sea coast may be preferred. In view of the possible discomforts and gastric disturbance which may attend a sea-voyage, this should be recommended to patients suffering from tuberculous lesions with more caution than has hitherto been exercised. The diet must be a liberal one, and should include those articles which are at the same time easily digested and nourishing, especially proteids and fats; milk obtained from a reliable source and underdone butcher-meat are among the best. When the ordinary nourishment taken is insufficient, it may be supplemented by such articles as malt extract, stout, and cod-liver oil. The last is specially beneficial in patients who do not take enough fat in other forms. It is noteworthy that many tuberculous patients show an aversion to fat.
Forthe use of tuberculin in diagnosisand forthe vaccine treatment of tuberculosisthe reader is referred to text-books on medicine.
In addition to increasing the resisting power of the patient, it is important to enable the fluids of the body, so altered, to come into contact with the tuberculous focus. One of the obstacles to this is that the focus is often surrounded by tissues or fluids which have been almost entirely deprived of bactericidal substances. In the case of caseated glands in the neck, for example, it is obvious that the removal of this inert material is necessary before the tissues can be irrigated with fluids of high bactericidal value. Again, in tuberculous ascites the abdominal cavity is filled with a fluid practically devoid of anti-bacterial substances, so that the bacilli are able to thrive and work their will on the tissues. When the stagnant fluid is got rid of by laparotomy, the parts are immediately douched with lymph charged with protective substances, the bactericidal power of which may be many times that of the fluid displaced.
It is probable that the beneficial influence ofcounter-irritants, such as blisters, and exposure to theFinsen lightand other forms ofrays, is to be attributed in part to the increased flow of blood to the infected tissues.
Artificial Hyperæmia.—As has been explained, the induction of hyperæmia by the method devised by Bier, constitutes one of our most efficient means of combating bacterial infection. The treatment of tuberculosis on this plan has been proved by experience to be a valuable addition to our therapeutic measures, and the simplicity of its application has led to its being widely adopted in practice. It results in an increase in the reactive changes around the tuberculous focus, an increase in the immigration of leucocytes, and infiltration with the lymphocytes.
The constricting bandage should be applied at some distance above the seat of infection; for instance, in disease of the wrist, it is put on above the elbow, and it must not cause pain either where it is applied or in the diseased part. The bandage is only applied for a few hours each day, either two hours at a time or twice a day for one hour, and, while it is on, all dressings are removed save a piece of sterile gauze over any wound or sinus that may be present. The process of cure takes a long time—nine or even twelve months in the case of a severe joint affection.
In cases in which a constricting bandage is inapplicable, for example, in cold abscesses, tuberculous glands or tendon sheaths, Klapp's suction bell is employed. The cup is applied for five minutes at a time and then taken off for three minutes,and this is repeated over a period of about three-quarters of an hour. The pus is allowed to escape by a small incision, and no packing or drain should be introduced.
It has been found that tuberculous lesions tend to undergo cure when the infected tissues are exposed to the rays of the sun—heliotherapy—therefore whenever practicable this therapeutic measure should be had recourse to.
Since the introduction of the methods of treatment described above, and especially by their employment at an early stage in the disease, the number of cases of tuberculosis requiring operative interference has greatly diminished. There are still circumstances, however, in which an operation is required; for example, in disease of the lymph glands for the removal of inert masses of caseous material, in disease of bone for the removal of sequestra, or in disease of joints to improve the function of the limb. It is to be understood, however, that operative treatment must always be preceded by and combined with other therapeutic measures.
The caseation of tuberculous granulation tissue and its liquefaction is a slow and insidious process, and is unattended with the classical signs of inflammation—hence the terms “cold†and “chronic†applied to the tuberculous abscess.
In a cold abscess, such as that which results from tuberculous disease of the vertebræ, the clinical appearances are those of a soft, fluid swelling without heat, redness, pain, or fever. When toxic symptoms are present, they are usually due to a mixed infection.
A tuberculous abscess results from the disintegration and liquefaction of tuberculous granulation tissue which has undergone caseation. Fluid and cells from the adjacent blood vessels exude into the cavity, and lead to variations in the character of its contents. In some cases the contents consist of a clear amber-coloured fluid, in which are suspended fragments of caseated tissue; in others, of a white material like cream-cheese. From the addition of a sufficient number of leucocytes, the contents may resemble the pus of an ordinary abscess.
The wall of the abscess is lined with tuberculous granulation tissue, the inner layers of which are undergoing caseation and disintegration, and present a shreddy appearance; the outer layers consist of tuberculous tissue which has not yet undergone caseation. The abscess tends to increase in size by progressive liquefaction of the inner layers, caseation of the outer layers, and the further invasion of the surrounding tissues by tubercle bacilli. In this way a tuberculous abscess is capable of indefinite extension and increase in size until it reaches a free surface and ruptures externally. The direction in which it spreads is influenced by the anatomical arrangement of the tissues, and possibly to some extent by gravity, and the abscess may reach the surface at a considerable distance from its seat of origin. The best illustration of this is seen in the psoas abscess, which may originate in the dorsal vertebræ, extend downwards within the sheath of the psoas muscle, and finally appear in the thigh.
Clinical Features.—The insidious development of the tuberculous abscess is one of its characteristic features. The swelling may attain a considerable size without the patient being aware of its existence, and, as a matter of fact, it is often discovered accidentally. The absence of toxæmia is to be associated with the incapacity of the wall of the abscess to permit of absorption; this is shown also by the fact that when even a large quantity of iodoform is inserted into the cavity of the abscess, there are no symptoms of poisoning. The abscess varies in size from a small cherry to a cavity containing several pints of pus. Its shape also varies; it is usually that of a flattened sphere, but it may present pockets or burrows running in various directions. Sometimes it is hour-glass or dumb-bell shaped, as is well illustrated in the region of the groin in disease of the spine or pelvis, where there may be a large sac occupying the venter ilii, and a smaller one in the thigh, the two communicating by a narrow channel under Poupart's ligament. By pressing with the fingers the pus may be displaced from one compartment to the other. The usual course of events is that the abscess progresses slowly, and finally reaches a free surface—generally the skin. As it does so there may be some pain, redness, and local elevation of temperature. Fluctuation becomes evident and superficial, and the skin becomes livid and finally gives way. If the case is left to nature, the discharge of pus continues, and the track opening on the skin remains as asinus. The persistence of suppuration is due to the presence in the wall of the abscess and of the sinus, of tuberculous granulation tissue, which, so long as it remains, continues to furnish discharge, and so prevents healing. Sooner or later pyogenic organisms gain access to the sinus, and through it to the wall of the abscess. They tend further to depress the resisting power of the tissues, and thereby aggravate and perpetuate the tuberculous disease.This superadded infection with pyogenic organisms exposes the patient to the further risks of septic intoxication, especially in the form of hectic fever and septicæmia, and increases the liability to general tuberculosis, and to waxy degeneration of the internal organs. The mixed infection is chiefly responsible for the pyrexia, sweating, and emaciation which the laity associate with consumptive disease. A tuberculous abscess may in one or other of these ways be a cause of death.
Residual abscessis the name given to an abscess that makes its appearance months, or even years, after the apparent cure of tuberculous disease—as, for example, in the hip-joint or spine. It is called residual because it has its origin in the remains of the original disease.