Manual of Surgery/Chapter VII

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CHAPTER VII

BACTERIAL AND OTHER WOUND INFECTIONS


_Erysipelas_--_Diphtheria_--_Tetanus_--_Hydrophobia_--_Anthrax_--

   _Glanders_--_Actinomycosis_--_Mycetoma_--_Delhi
   boil_--_Chigoe_--_Poisoning by insects_--_Snake-bites_.


ERYSIPELAS

Erysipelas, popularly known as "rose," is an acute spreading infective disease of the skin or of a mucous membrane due to the action of a streptococcus. Infection invariably takes place through an abrasion of the surface, although this may be so slight that it escapes observation even when sought for. The streptococci are found most abundantly in the lymph spaces just beyond the swollen margin of the inflammatory area, and in the serous blebs which sometimes form on the surface.

  1. Clinical Features.#--_Facial erysipelas_ is the commonest clinical

variety, infection usually occurring through some slight abrasion in the region of the mouth or nose, or from an operation wound in this area. From this point of origin the inflammation may spread all over the face and scalp as far back as the nape of the neck. It stops, however, at the chin, and never extends on to the front of the neck. There is great oedema of the face, the eyes becoming closed up, and the features unrecognisable. The inflammation may spread to the meninges, the intracranial venous sinuses, the eye, or the ear. In some cases the erysipelas invades the mucous membrane of the mouth, and spreads to the fauces and larynx, setting up an oedema of the glottis which may prove dangerous to life.

Erysipelas occasionally attacks an operation wound that has become septic; and it may accompany septic infection of the genital tract in puerperal women, or the separation of the umbilical cord in infants (_erysipelas neonatorum_). After an incubation period, which varies from fifteen to sixty hours, the patient complains of headache, pains in the back and limbs, loss of appetite, nausea, and frequently there is vomiting. He has a chill or slight rigor, initiating a rise of temperature to 103, 104, or 105 F.; and a full bounding pulse of about 100 (Fig. 25). The tongue is foul, the breath heavy, and, as a rule, the bowels are constipated. There is frequently albuminuria, and occasionally nocturnal delirium. A moderate degree of leucocytosis (15,000 to 20,000) is usually present.

Around the seat of inoculation a diffuse red patch forms, varying in hue from a bright scarlet to a dull brick-red. The edges are slightly raised above the level of the surrounding skin, as may readily be recognised by gently stroking the part from the healthy towards the affected area. The skin is smooth, tense, and glossy, and presents here and there blisters filled with serous fluid. The local temperature is raised, and the part is the seat of a burning sensation and is tender to the touch, the most tender area being the actively spreading zone which lies about half an inch beyond the red margin.

[Illustration: FIG. 25.--Chart of Erysipelas occurring in a wound.]

The disease tends to spread spasmodically and irregularly, and the direction and extent of its progress may be recognised by mapping out the peripheral zone of tenderness. Red streaks appear along the lines of the superficial lymph vessels, and the deep lymphatics may sometimes be palpated as firm, tender cords. The neighbouring glands, also, are generally enlarged and tender.

The disease lasts for from two or three days to as many weeks, and relapses are frequent. Spontaneous resolution usually takes place, but the disease may prove fatal from absorption of toxins, involvement of the brain or meninges, or from general streptococcal infection.

  1. Complications.#--_Diffuse suppurative cellulitis_ is the most serious

local complication, and results from a mixed infection with other pyogenic bacteria. Small _localised superficial abscesses_ may form during the convalescent stage. They are doubtless due to the action of skin bacteria, which attack the tissues devitalised by the erysipelas. A persistent form of _oedema_ sometimes remains after recurrent attacks of erysipelas, especially when they affect the face or the lower extremity, a condition which is referred to with elephantiasis.

  1. Treatment.#--The first indication is to endeavour to arrest the spread

of the process. We have found that by painting with linimentum iodi, a ring half an inch broad, about an inch in front of the peripheral tender zone--not the red margin--an artificial leucocytosis is produced, and the advancing streptococci are thereby arrested. Several coats of the iodine are applied, one after the other, and this is repeated daily for several days, even although the erysipelas has not overstepped the ring. Success depends upon using the liniment of iodine (the tincture is not strong enough), and in applying it well in front of the disease. To allay pain the most useful local applications are ichthyol ointment (1 in 6), or lead and opium fomentations.

The general treatment consists in attending to the emunctories, in administrating quinine in small--two-grain--doses every four hours, or salicylate of iron (2-5 gr. every three hours), and in giving plenty of fluid nourishment. It is worthy of note that the anti-streptococcic serum has proved of less value in the treatment of erysipelas than might have been expected, probably because the serum is not made from the proper strain of streptococcus.

It is not necessary to isolate cases of erysipelas, provided the usual precautions against carrying infection from one patient to another are rigidly carried out.


DIPHTHERIA

Diphtheria is an acute infective disease due to the action of a specific bacterium, the _bacillus diphtheriae_ or _Klebs-Loffler bacillus_. The disease is usually transmitted from one patient to another, but it may be contracted from cats, fowls, or through the milk of infected cows. Cases have occurred in which the surgeon has carried the infection from one patient to another through neglect of antiseptic precautions. The incubation period varies from two to seven days.

  1. Clinical Features.#--In _pharyngeal diphtheria_, on the first or

second day of the disease, redness and swelling of the mucous membrane of the pharynx, tonsils, and palate are well marked, and small, circular greenish or grey patches of false membrane, composed of necrosed epithelium, fibrin, leucocytes, and red blood corpuscles, begin to appear. These rapidly increase in area and thickness, till they coalesce and form a complete covering to the parts. In the pharynx the false membrane is less adherent to the surface than it is when the disease affects the air-passages. The diphtheritic process may spread from the pharynx to the nasal cavities, causing blocking of the nares, with a profuse ichorous discharge from the nostrils, and sometimes severe epistaxis. The infection may spread along the nasal duct to the conjunctiva. The middle ear also may become involved by spread along the auditory (Eustachian) tube.

The lymph glands behind the angle of the jaw enlarge and become tender, and may suppurate from superadded infection. There is pain on swallowing, and often earache; and the patient speaks with a nasal accent. He becomes weak and anaemic, and loses his appetite. There is often albuminuria. Leucocytosis is usually well marked before the injection of antitoxin; after the injection there is usually a diminution in the number of leucocytes. The false membrane may separate and be cast off, after which the patient gradually recovers. Death may take place from gradual failure of the heart's action or from syncope during some slight exertion.

_Laryngeal Diphtheria._--The disease may arise in the larynx, although, as a rule, it spreads thence from the pharynx. It first manifests itself by a short, dry, croupy cough, and hoarseness of the voice. The first difficulty in breathing usually takes place during the night, and once it begins, it rapidly gets worse. Inspiration becomes noisy, sometimes stridulous or metallic or sibilant, and there is marked indrawing of the epigastrium and lower intercostal spaces. The hoarseness becomes more marked, the cough more severe, and the patient restless. The difficulty of breathing occurs in paroxysms, which gradually increase in frequency and severity, until at length the patient becomes asphyxiated. The duration of the disease varies from a few hours to four or five days.

After the acute symptoms have passed off, various localised paralyses may develop, affecting particularly the nerves of the palatal and orbital muscles, less frequently the lower limbs.

  1. Diagnosis.#--The finding of the Klebs-Loffler bacillus is the only

conclusive evidence of the disease. The bacillus may be obtained by swabbing the throat with a piece of aseptic--not antiseptic--cotton wool or clean linen rag held in a pair of forceps, and rotated so as to entangle portions of the false membrane or exudate. The swab thus obtained is placed in a test-tube, previously sterilised by having had some water boiled in it, and sent to a laboratory for investigation. To identify the bacillus a piece of the membrane from the swab is rubbed on a cover glass, dried, and stained with methylene blue or other basic stain; or cultures may be made on agar or other suitable medium. When a bacteriological examination is impossible, or when the clinical features do not coincide with the results obtained, the patient should always be treated on the assumption that he suffers from diphtheria. So much doubt exists as to the real nature of membranous croup and its relationship to true diphtheria, that when the diagnosis between the two is uncertain the safest plan is to treat the case as one of diphtheria.

In children, diphtheria may occur on the vulva, vagina, prepuce, or glans penis, and give rise to difficulty in diagnosis, which is only cleared up by demonstration of the bacillus.

  1. Treatment.#--An attempt may be made to destroy or to counteract the

organisms by swabbing the throat with strong antiseptic solutions, such as 1 in 1000 corrosive sublimate or 1 in 30 carbolic acid, or by spraying with peroxide of hydrogen.

The antitoxic serum is our sheet-anchor in the treatment of diphtheria, and recourse should be had to its use as early as possible.

Difficulty of swallowing may be met by the use of a stomach tube passed either through the mouth or nose. When this is impracticable, nutrient enemata are called for.

In laryngeal diphtheria, the interference with respiration may call for intubation of the larynx, or tracheotomy, but the antitoxin treatment has greatly diminished the number of cases in which it becomes necessary to have recourse to these measures.

Intubation consists in introducing through the mouth into the larynx a tube which allows the patient to breathe freely during the period while the membrane is becoming separated and thrown off. This is best done with the apparatus of O'Dwyer; but when this instrument is not available, a simple gum-elastic catheter with a terminal opening (as suggested by Macewen and Annandale) may be employed.

When intubation is impracticable, the operation of tracheotomy is called for if the patient's life is endangered by embarrassment of respiration. Unless the patient is in hospital with skilled assistance available, tracheotomy is the safer of the two procedures.


TETANUS

Tetanus is a disease resulting from infection of a wound by a specific micro-organism, the _bacillus tetani_, and characterised by increased reflex excitability, hypertonus, and spasm of one or more groups of voluntary muscles.

_Etiology and Morbid Anatomy._--The tetanus bacillus, which is a perfect anaerobe, is widely distributed in nature and can be isolated from garden earth, dung-heaps, and stable refuse. It is a slender rod-shaped bacillus, with a single large spore at one end giving it the shape of a drum-stick (Fig. 26). The spores, which are the active agents in producing tetanus, are highly resistant to chemical agents, retain their vitality in a dry condition, and even survive boiling for five minutes.

The organism does not readily establish itself in the human body, and seems to flourish best when it finds a nidus in necrotic tissue and is accompanied by aerobic organisms, which, by using up the oxygen in the tissues, provide for it a suitable environment. The presence of a foreign body in the wound seems to favour its action. The infection is for all practical purposes a local one, the symptoms of the disease being due to the toxins produced in the wound of infection acting upon the central nervous system.

The toxin acts principally on the nerve centres in the spinal medulla, to which it travels from the focus of infection by way of the nerve fibres supplying the voluntary muscles. Its first effect on the motor ganglia of the cord is to render them hypersensitive, so that they are excited by mild stimuli, which under ordinary conditions would produce no reaction. As the toxin accumulates the reflex arc is affected, with the result that when a stimulus reaches the ganglia a motor discharge takes place, which spreads by ascending and descending collaterals to the reflex apparatus of the whole cord. As the toxin spreads it causes both motor hyper-tonus and hyper-excitability, which accounts for the tonic contraction and the clonic spasms characteristic of tetanus.

[Illustration: FIG. 26.--Bacillus of Tetanus from scraping of a wound of finger, x 1000 diam. Basic fuchsin stain.]

  1. Clinical Varieties of Tetanus.#--_Acute_ or _Fulminating

Tetanus_.--This variety is characterised by the shortness of the incubation period, the rapidity of its progress, the severity of its symptoms, and its all but universally fatal issue in spite of treatment, death taking place in from one to four days. The characteristic symptoms may appear within three or four days of the infliction of the wound, but the incubation period may extend to three weeks, and the wound may be quite healed before the disease declares itself--_delayed tetanus_. Usually, however, the wound is inflamed and suppurating, with ragged and sloughy edges. A slight feverish attack may mark the onset of the tetanic condition, or the patient may feel perfectly well until the spasms begin. If careful observations be made, it may be found that the muscles in the immediate neighbourhood of the wound are the first to become contracted; but in the majority of instances the patient's first complaint is of pain and stiffness in the muscles of mastication, notably the masseter, so that he has difficulty in opening the mouth--hence the popular name "lock-jaw." The muscles of expression soon share in the rigidity, and the face assumes a taut, mask-like aspect. The angles of the mouth may be retracted, producing a grinning expression known as the _risus sardonicus_.

The next muscles to become stiff and painful are those of the neck, especially the sterno-mastoid and trapezius. The patient is inclined to attribute the pain and stiffness to exposure to cold or rheumatism. At an early stage the diaphragm and the muscles of the anterior abdominal wall become contracted; later the muscles of the back and thorax are involved; and lastly those of the limbs. Although this is the typical order of involvement of the different groups of muscles, it is not always adhered to.

To this permanent tonic contraction of the muscles there are soon added clonic spasms. These spasms are at first slight and transient, with prolonged intervals between the attacks, but rapidly tend to become more frequent, more severe, and of longer duration, until eventually the patient simply passes out of one seizure into another.

The distribution of the spasms varies in different cases: in some it is confined to particular groups of muscles, such as those of the neck, back, abdominal walls, or limbs; in others all these groups are simultaneously involved.

When the muscles of the back become spasmodically contracted, the body is raised from the bed, sometimes to such an extent that the patient rests only on his heels and occiput--the position of _opisthotonos_. Lateral arching of the body from excessive action of the muscles on one side--_pleurosthotonos_--is not uncommon, the arching usually taking place towards the side on which the wound of infection exists. Less frequently the body is bent forward so that the knees and chin almost meet (_emprosthotonos_). Sometimes all the muscles simultaneously become rigid, so that the body assumes a statuesque attitude (_orthotonos_). When the thoracic muscles, including the diaphragm, are thrown into spasm, the patient experiences a distressing sensation as if he were gripped in a vice, and has extreme difficulty in getting breath. Between the attacks the limbs are kept rigidly extended. The clonic spasms may be so severe as to rupture muscles or even to fracture one of the long bones.

As time goes on, the clonic exacerbations become more and more frequent, and the slightest external stimulus, such as the feeling of the pulse, a whisper in the room, a noise in the street, a draught of cold air, the effort to swallow, a question addressed to the patient or his attempt to answer, is sufficient to determine an attack. The movements are so forcible and so continuous that the nurse has great difficulty in keeping the bedclothes on the patient, or even in keeping him in bed.

The general condition of the patient is pitiful in the extreme. He is fully conscious of the gravity of the disease, and his mind remains clear to the end. The suffering induced by the cramp-like spasms of the muscles keeps him in a constant state of fearful apprehension of the next seizure, and he is unable to sleep until he becomes utterly exhausted.

The temperature is moderately raised (100 to 102 F.), or may remain normal throughout. Shortly before death very high temperatures (110 F.) have been recorded, and it has been observed that the thermometer sometimes continues to rise after death, and may reach as high as 112 F. or more.

The pulse corresponds with the febrile condition. It is accelerated during the spasms, and may become exceedingly rapid and feeble before death, probably from paralysis of the vagus. Sudden death from cardiac paralysis or from cardiac spasm is not uncommon.

The respiration is affected in so far as the spasms of the respiratory muscles produce dyspnoea, and a feeling of impending suffocation which adds to the horrors of the disease.

One of the most constant symptoms is a copious perspiration, the patient being literally bathed in sweat. The urine is diminished in quantity, but as a rule is normal in composition; as in other acute infective conditions, albumen and blood may be present. Retention of urine may result from spasm of the urethral muscles, and necessitate the use of the catheter.

The fits may cease some time before death, or, on the other hand, death may occur during a paroxysm from fixation of the diaphragm and arrest of respiration.

_Differential Diagnosis._--There is little difficulty, as a rule, in diagnosing a case of fulminating tetanus, but there are several conditions with which it may occasionally be confused. In _strychnin poisoning_, for example, the spasms come on immediately after the patient has taken a toxic dose of the drug; they are clonic in character, but the muscles are relaxed between the fits. If the dose is not lethal, the spasms soon cease. In _hydrophobia_ a history of having been bitten by a rabid animal is usually forthcoming; the spasms, which are clonic in character, affect chiefly the muscles of respiration and deglutition, and pass off entirely in the intervals between attacks. Certain cases of _haemorrhage into the lateral ventricles_ of the brain also simulate tetanus, but an analysis of the symptoms will prevent errors in diagnosis. _Cerebro-spinal meningitis_ and _basal meningitis_ present certain superficial resemblances to tetanus, but there is no trismus, and the spasms chiefly affect the muscles of the neck and back. _Hysteria and catalepsy_ may assume characters resembling those of tetanus, but there is little difficulty in distinguishing between these diseases. Lastly, in the _tetany_ of children, or that following operations on the thyreoid gland, the spasms are of a jerking character, affect chiefly the hands and fingers, and yield to medicinal treatment.

  1. Chronic Tetanus.#--The difference between this and acute tetanus is

mainly one of degree. Its incubation period is longer, it is more slow and insidious in its progress, and it never reaches the same degree of severity. Trismus is the most marked and constant form of spasm; and while the trunk muscles may be involved, those of respiration as a rule escape. Every additional day the patient lives adds to the probability of his ultimate recovery. When the disease does prove fatal, it is from exhaustion, and not from respiratory or cardiac spasm. The usual duration is from six to ten weeks.

  1. Delayed Tetanus.#--During the European War acute tetanus occasionally

developed many weeks or even months after a patient had been injured, and when the original wound had completely healed. It usually followed some secondary operation, _e.g._, for the removal of a foreign body, or the breaking down of adhesions, which aroused latent organisms.

  1. Local Tetanus.#--This term is applied to a form of the disease in which

the hypertonus and spasms are localised to the muscles in the vicinity of the wound. It usually occurs in patients who have had prophylactic injections of anti-tetanic serum, the toxins entering the blood being probably neutralised by the antibodies in circulation, while those passing along the motor nerves are unaffected.

When it occurs in the _limbs_, attention is usually directed to the fact by pain accompanying the spasms; the muscles are found to be hard and there are frequent twitchings of the limb. A characteristic reflex is present in the lower extremity, namely, extension of the foot and leg when the sole is tickled.

_Cephalic Tetanus_ is another localised variety which follows injury in the distribution of the facial nerve. It is characterised by the occurrence on the same side as the injury, of facial spasm, rapidly followed by more or less complete paralysis of the muscles of expression, with unilateral trismus and difficulty in swallowing. Other cranial nerves, particularly the oculomotor and the hypoglossal, may also be implicated. A remarkable feature of this condition is that although the muscles are irresponsive to ordinary physiological stimuli, they are thrown into spasm by the abnormal impulses of tetanus.

_Trismus._--This term is used to denote a form of tetanic spasm limited to the muscles of mastication. It is really a mild form of chronic tetanus, and the prognosis is favourable. It must not be confused with the fixation of the jaw sometimes associated with a wisdom-tooth gumboil, with tonsillitis, or with affections of the temporo-mandibular articulation.

_Tetanus neonatorum_ is a form of tetanus occurring in infants of about a week old. Infection takes place through the umbilicus, and manifests itself clinically by spasms of the muscles of mastication. It is almost invariably fatal within a few days.

_Prophylaxis._--Experience in the European War has established the fact that the routine injection of anti-tetanic serum to all patients with lacerated and contaminated wounds greatly reduces the frequency of tetanus. The sooner the serum is given after the injury, the more certain is its effect; within twenty-four hours 1500 units injected subcutaneously is sufficient for the initial dose; if a longer period has elapsed, 2000 to 3000 units should be given intra-muscularly, as this ensures more rapid absorption. A second injection is given a week after the first.

The wound must be purified in the usual way, and all instruments and appliances used for operations on tetanic patients must be immediately sterilised by prolonged boiling.

_Treatment._--When tetanus has developed the main indications are to prevent the further production of toxins in the wound, and to neutralise those that have been absorbed into the nervous system. Thorough purification with antiseptics, excision of devitalised tissues, and drainage of the wound are first carried out. To arrest the absorption of toxins intra-muscular injections of 10,000 units of serum are given daily into the muscles of the affected limb, or directly into the nerve trunks leading from the focus of infection, in the hope of "blocking" the nerves with antitoxin and so preventing the passage of toxins towards the spinal cord.

To neutralise the toxins that have already reached the spinal cord, 5000 units should be injected intra-thecally daily for four or five days, the foot of the bed being raised to enable the serum to reach the upper parts of the cord.

The quantity of toxin circulating in the blood is so small as to be practically negligible, and the risk of anaphylactic shock attending intra-venous injection outweighs any benefit likely to follow this procedure.

Baccelli recommends the injection of 20 c.c. of a 1 in 100 solution of carbolic acid into the subcutaneous tissues every four hours during the period that the contractions persist. Opinions vary as to the efficiency of this treatment. The intra-thecal injection of 10 c.c. of a 15 per cent. solution of magnesium sulphate has proved beneficial in alleviating the severity of the spasms, but does not appear to have a curative effect.

To conserve the patient's strength by preventing or diminishing the severity of the spasms, he should be placed in a quiet room, and every form of disturbance avoided. Sedatives, such as bromides, paraldehyde, or opium, must be given in large doses. Chloral is perhaps the best, and the patient should rarely have less than 150 grains in twenty-four hours. When he is unable to swallow, it should be given by the rectum. The administration of chloroform is of value in conserving the strength of the patient, by abolishing the spasms, and enabling the attendants to administer nourishment or drugs either through a stomach tube or by the rectum. Extreme elevation of temperature is met by tepid sponging. It is necessary to use the catheter if retention of urine occurs.


HYDROPHOBIA

Hydrophobia is an acute infective disease following on the bite of a rabid animal. It most commonly follows the bite or lick of a rabid dog or cat. The virus appears to be communicated through the saliva of the animal, and to show a marked affinity for nerve tissues; and the disease is most likely to develop when the patient is infected on the face or other uncovered part, or in a part richly endowed with nerves.

A dog which has bitten a person should on no account be killed until its condition has been proved one way or the other. Should rabies develop and its destruction become necessary, the head and spinal cord should be retained and forwarded, packed in ice, to a competent observer. Much anxiety to the person bitten and to his friends would be avoided if these rules were observed, because in many cases it will be shown that the animal did not after all suffer from rabies, and that the patient consequently runs no risk. If, on the other hand, rabies is proved to be present, the patient should be submitted to the Pasteur treatment.

_Clinical Features._--There is almost always a history of the patient having been bitten or licked by an animal supposed to suffer from rabies. The incubation period averages about forty days, but varies from a fortnight to seven or eight months, and is shorter in young than in old persons. The original wound has long since healed, and beyond a slight itchiness or pain shooting along the nerves of the part, shows no sign of disturbance. A few days of general malaise, with chills and giddiness precede the onset of the acute manifestations, which affect chiefly the muscles of deglutition and respiration. One of the earliest signs is that the patient has periodically a sudden catch in his breathing "resembling what often occurs when a person goes into a cold bath." This is due to spasm of the diaphragm, and is frequently accompanied by a loud-sounding hiccough, likened by the laity to the barking of a dog. Difficulty in swallowing fluids may be the first symptom.

The spasms rapidly spread to all the muscles of deglutition and respiration, so that the patient not only has the greatest difficulty in swallowing, but has a constant sense of impending suffocation. To add to his distress, a copious secretion of viscid saliva fills his mouth. Any voluntary effort, as well as all forms of external stimuli, only serve to aggravate the spasms which are always induced by the attempt to swallow fluid, or even by the sound of running water.

The temperature is raised; the pulse is small, rapid, and intermittent; and the urine may contain sugar and albumen.

The mind may remain clear to the end, or the patient may have delusions, supposing himself to be surrounded by terrifying forms. There is always extreme mental agitation and despair, and the sufferer is in constant fear of his impending fate. Happily the inevitable issue is not long delayed, death usually occurring in from two to four days from the onset. The symptoms of the disease are so characteristic that there is no difficulty in diagnosis. The only condition with which it is liable to be confused is the variety of cephalic tetanus in which the muscles of deglutition are specially involved--the so-called tetanus hydrophobicus.

_Prophylaxis._--The bite of an animal suspected of being rabid should be cauterised at once by means of the actual or Paquelin cautery, or by a strong chemical escharotic such as pure carbolic acid, after which antiseptic dressings are applied.

It is, however, to Pasteur's _preventive inoculation_ that we must look for our best hope of averting the onset of symptoms. "It may now be taken as established that a grave responsibility rests on those concerned if a person bitten by a mad animal is not subjected to the Pasteur treatment" (Muir and Ritchie).

This method is based on the fact that the long incubation period of the disease admits of the patient being inoculated with a modified virus producing a mild attack, which protects him from the natural disease.

_Treatment._--When the symptoms have once developed they can only be palliated. The patient must be kept absolutely quiet and free from all sources of irritation. The spasms may be diminished by means of chloral and bromides, or by chloroform inhalation.


ANTHRAX

Anthrax is a comparatively rare disease, communicable to man from certain of the lower animals, such as sheep, oxen, horses, deer, and other herbivora. In animals it is characterised by symptoms of acute general poisoning, and, from the fact that it produces a marked enlargement of the spleen, is known in veterinary surgery as "splenic fever."

The _bacillus anthracis_ (Fig. 27), the largest of the known pathogenic bacteria, occurs in groups or in chains made up of numerous bacilli, each bacillus measuring from 6 to 8 [micron] in length. The organisms are found in enormous numbers throughout the bodies of animals that have died of anthrax, and are readily recognised and cultivated. Sporulation only takes place outside the body, probably because free oxygen is necessary to the process. In the spore-free condition, the organisms are readily destroyed by ordinary germicides, and by the gastric juice. The spores, on the other hand, have a high degree of resistance. Not only do they remain viable in the dry state for long periods, even up to a year, but they survive boiling for five minutes, and must be subjected to dry heat at 140 C. for several hours before they are destroyed.

[Illustration: FIG. 27.--Bacillus of Anthrax in section of skin, from a case of malignant pustule; shows vesicle containing bacilli. x 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 as _the 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 as _wool-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.

  1. 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 oedematous, 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--_anthracaemia_--the temperature rises to 103 or 104 F., the pulse becomes feeble and rapid, and other signs of severe blood-poisoning appear: vomiting, diarrhoea, 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 oedema 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.

[Illustration: FIG. 28.--Malignant Pustule, third day after infection with Anthrax, showing great oedema of upper extremity and pectoral region (cf. Fig. 29).]

[Illustration: FIG. 29.--Malignant Pustule, fourteen days after infection, showing black eschar in process of separation. The oedema 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. Graf has had excellent results by the latter method in a large series of cases, the oedema 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 10 grain doses every four hours, and powdered ipecacuanha, in 40 to 60 grain doses every four hours, have also been employed with apparent benefit.


GLANDERS

Glanders is due to the action of a specific bacterium, the _bacillus 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_, and _chronic glanders_ or _farcy_.

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 nodules subsequently 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.

The _local_ manifestations 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 pyaemic 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 septicaemia or pyaemia. The diagnosis is established by the recognition of the bacillus. Veterinary surgeons 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.

  1. Chronic Glanders.#--_In the horse_ the chronic form of glanders is

known as _farcy_, 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 call _farcy pipes_ and _farcy buds_.

_In man_ also 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 50 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.

The _differential diagnosis_ is 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

Actinomycosis is a chronic disease due to the action of an organism somewhat higher in the vegetable scale than ordinary bacteria--the _streptothrix actinomyces_ or _ray fungus_.

[Illustration: FIG. 30.--Section of Actinomycosis Colony in Pus from Abscess of Liver, showing filaments and clubs of streptothrix actinomyces. x 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 pyaemia. 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 branching _filaments_, some of which are broken up so as to form masses or chains of _cocci_; 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 pyaemia.

_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 vertebrae may become involved by infection taking place through the pharynx or oesophagus, 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.

[Illustration: 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 10 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.

[Illustration: 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 serum exudes, 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.

The _treatment_ consists 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 hyperaemia, 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 oedema of the glottis, which may prove fatal.

The _treatment_ consists 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 ammoniae.

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 the _venom_.

The _clinical features_ resulting 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.

_Locally_ the 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.

The _general symptoms_ may 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, haematuria, and melaena 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 general circulation, 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 the _antivenin_ introduced by Fraser and Calmette.