CHAPTER VII
BACTERIAL AND OTHER WOUND INFECTIONS
_Erysipelas_--_Diphtheria_--_Teta.n.u.s_--_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 s.p.a.ces just beyond the swollen margin of the inflammatory area, and in the serous blebs which sometimes form on the surface.
#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 dema 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 dema 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 appet.i.te, 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 alb.u.minuria, 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.
[Ill.u.s.tration: 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.
#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 _dema_ 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.
#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 (25 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.
#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-pa.s.sages. 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 appet.i.te. There is often alb.u.minuria. Leucocytosis is usually well marked before the injection of ant.i.toxin; 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 hoa.r.s.eness 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 s.p.a.ces. The hoa.r.s.eness 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 pa.s.sed off, various localised paralyses may develop, affecting particularly the nerves of the palatal and orbital muscles, less frequently the lower limbs.
#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 gla.s.s, 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 a.s.sumption 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 v.u.l.v.a, v.a.g.i.n.a, prepuce, or glans p.e.n.i.s, and give rise to difficulty in diagnosis, which is only cleared up by demonstration of the bacillus.
#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 ant.i.toxic 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 pa.s.sed 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 ant.i.toxin 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 embarra.s.sment of respiration. Unless the patient is in hospital with skilled a.s.sistance available, tracheotomy is the safer of the two procedures.
TETa.n.u.s
Teta.n.u.s 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 teta.n.u.s 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 teta.n.u.s, 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 princ.i.p.ally 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 acc.u.mulates 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 teta.n.u.s.
[Ill.u.s.tration: FIG. 26.--Bacillus of Teta.n.u.s from sc.r.a.ping of a wound of finger, 1000 diam. Basic fuchsin stain.]
#Clinical Varieties of Teta.n.u.s.#--_Acute_ or _Fulminating Teta.n.u.s_.--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 teta.n.u.s_. 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 ma.s.seter, 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 a.s.sumes 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 pa.s.ses 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 a.s.sumes a statuesque att.i.tude (_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 dyspna, and a feeling of impending suffocation which adds to the horrors of the disease.