INFECTIVE LYMPHANGITIS. TRAUMATIC LYMPHANGITIS.
Infection varied, through wounds, autogenous. Simple irritation, simple lymphangitis. Causes, sun’s rays, bruises, other injuries, lymph coagulation from heat, cold, chemical irritants, and coagulants. Germs in blood act on debilitated tissues, lymphatic constitutions, anæmic, overworked, or starved. Insect bites, claws, teeth of carnivora, foul instruments, fingers or clothes. Bloodless wounds dangerous. Distal parts of the limbs exposed. Fresh wound exposed, granulating less so. Most microbes enter by the lymphatics. Symptoms, extension from wound, swollen lymphatics, reticular lymphangitis, tubular lymphangitis, farcy, tuberculous case, slough. Fever variable. General infection. Joint infection. Chronic cases. Lesions. Diagnosis, from phlebitis. Treatment, antiseptics, diet, eliminants, antithermics, blisters, mercurial ointment, iodine, lancing, tonics, massage, bandage.
Under this heading must be named not one specific disease but a group of infections entering by the lymphatic vessels and developing inflammation of their substance. They may be divided into two classes: those caused by infection through external wounds and those in which the poison already in the system becomes localized on a weak or exposed tissue.
A third class must be included, in which there is no recognizable poison but simply a local irritation which leads to coagulation or other alteration in the lymph, or disease of the lymphatic vessels.
This subject belongs rather to surgery than medicine but it seems necessary to contrast it here with the plethoric form of equine lymphangitis. Most of its forms pertain to infectious diseases and will be treated in connection with these.
Causes of Simple Lymphangitis. Formerly many forms of lymphangitis were ascribed to mere local irritation; a superficial form will occur from exposure to the rays of the sun, and an inflammation attendant on a bruise or other injury with unbroken skin, may cause local inflammation of the lymph vessels and enlargement of the adjacent lymph glands. As we have seen above coagulation of the lymph and fibrine embolism may induce local inflammation in the walls, and this may occur in connection with excessive heat or cold or the presence of chemical irritants and coagulants. These cases are however rarely serious and the tendency today is to trace nearly all cases to infection, from germs already present in the lymph or blood, or introduced through a wound or sore. The effect of germs already circulating was shown in the beautiful demonstrations of Chauveau in regard to calves subjected to castration by subcutaneous torsion (bistournage). In the healthy calf the simple operation gave rise to little disturbance. The healthy calf injected with septic liquids equally escaped visible trouble. But the calf injected with septic liquids and then subjected to bistournage had a fatal infecting inflammation. There is a strong presumption that, in lymphangitis, starting from an injury with no external sore, the germs were already present in the blood or tissues but were unable to do any serious damage until the injured and weakened part or organ offered an area of lessened resistance to their colonization. Following the same line of thought it has been noticed that animals of a coarse texture, and lymphatic constitution (heavy draft horses and animals raised for the butcher), and such as are debilitated by anæmia, overwork, or poor and insufficient nourishment are above all liable to be attacked by lymphangitis.
The insertion of the septic poison may take place through the bites of insects, the claws, or teeth of carnivora that have been devouring tainted or infecting meat, through the lancet or operating instrument of the surgeon, by his fingers or the dust from his hair or clothes. The wound is perhaps more likely to be infecting if it leads to no effusion of blood, but affects only the thickness of the epidermis, as there is less chance for the washing out of germs by the flowing blood, and there is less care to employ antiseptics. Wounds in the feet and lower parts of the limbs are specially liable to infection by reason of their frequent contact with manure and decomposing organic matter in the soil.
A fresh wound, in which the lymph spaces are exposed, is somewhat more open to infection than one that has advanced to the stage of granulation, the layer of unorganized lymph and cells acting as a slight barrier to the passage of the microbes.
Nearly all microbian diseases make their inroad by way of the lymphatics, where the sparse cells fail to establish as active phagocytosis as do the numerous moving cells of the blood. Hence a number of infectious maladies are primarily and pre-eminently diseases of the lymphatics, as glanders, strangles, tuberculosis, cancer, anthrax, swine-plague, etc.
Symptoms. The most common form is where lymphangitis extends from some pre-existing wound—as pricked or suppurating foot, fistula of foot, withers or poll, chafing of shoulder or back, cracked heels, boil, sloughing bruise, etc. The swelling around the sore or injury involves in fact the radical lymphatic plexus in the connective tissue (reticular lymphangitis). When the swelling extends and becomes more tense, with firm, painful sinuous cords running out of it in different directions, and especially toward the nearest lymphatic glands, and when these glands are slightly swollen and tender, tubular lymphangitis is diagnosed. No more striking example can be found than in skin glanders (farcy). The rigid cords extend from the side of the face, from the eye, and nose down toward the submaxillary glands and with more or less adjacent engorgement. Or on a hind limb, or some portion of the trunk, a more or less turgid swelling with one or more firm nodes (farcy buds) and painful, tortuous cords running towards the lymph glands is very characteristic.
A tuberculous case may show an indolent, hard, comparatively insensible cutaneous cord leading toward the jugular furrow, the prescapular, precrural or inguinal glands, and at long intervals softening, fluctuating, bursting and discharging a thick pus. In a carcinoma there is the old, hard, nodular, and finally ulcerating swelling from which the firm cords extend to the mass of steadily enlarging lymphatic glands.
A simpler form is where a bruise by the harness causes a hard, thick, slough, embracing the entire thickness of the skin, from which the firm corded lymphatics extend in different directions. After the slow process of detachment, the local lymphangitis usually subsides under simple cooling or antiseptic treatment.
But the grade of such lymphangitis is as varied as the particular germ or combination of germs present in the wound, and the susceptibility of the animal attacked, and there will be high, moderate or no fever, according to the severity of the case, and in some cases purely local trouble and in others general infection with purulent or septic localization in distant parts. There is always danger of extension to a neighboring joint with destructive results.
A curious outbreak is described by Wiart as attacking nearly every horse in the regiment that sustained a slight wound. A tubercle looking mass formed in the depth of the wound was slow to heal, and the lymphatics leading out from it became round, corded, turgid, and at long intervals developed along their course fluctuating centres which, whether opened spontaneously or by the lancet, showed the same indolent habit. A single attack would last from two to six months, and the actual cautery had to be used on the sores.
The lesions are those already described in the last article for simple lymphangitis. For infecting cases they are those of the particular disease which may be present.
Diagnosis. The general diagnosis of lymphangitis is the distinction from phlebitis. In phlebitis the vein is blocked and cannot be raised by pressure on the side leading toward the heart; in lymphangitis it can be so raised. The swelling and tenderness are both greater in lymphangitis. The inflamed vein is more rectilinear, the lymph vessel somewhat sinuous. If suppuration ensues it is more diffuse in lymphangitis; more restricted and mixed with the elements of blood in phlebitis.
For identification of the particular forms of infecting lymphangitis, the reference must be made to the individual infectious diseases.
Treatment. In general the treatment of lymphangitis is the antisepsis of wounds. Further than this the treatment of each case is that of the particular disease which it represents. For all cases alike it is important to apply vigorous treatment early, so as to cut it short before it can attain a dangerous extension.
For the simpler forms of lymphangitis the wound should first be thoroughly cleansed and disinfected. Washing with soap suds, or carbonate of soda will remove any greasy agent which would prevent a thorough antisepsis. Then it may be washed with the antiseptic lotion:—carbolic acid solution (1:20), or mercuric chloride solution (1:500), or zinc chloride (1:400) or potassium permanganate (1:160). If the infection has been introduced by a small or punctured wound, the sting or bite of an insect, or the prick of a sharp instrument it should be freely cauterized to its depth with lunar caustic incising it if need be to reach the whole of the poison, and the surface afterward dressed with antiseptics.
The diet should be light but nutritious and laxative, and the free action of the bowels and kidneys should be maintained by salines. When fever runs high give quinine, or salicylate of soda. When a large wound has to be dressed it may be requisite to use a non-poisonous agent like acetate of aluminium or boric acid to irrigate it thoroughly. In some such cases packing the irrigated wound with iodoform gauze has often an excellent effect.
When there is a firm inflamed cord, hot and painful, a fly blister along its course followed by mercurial ointment often gives excellent results. Or they may be repeatedly painted with tincture of iodine.
Foci of suppuration must be promptly opened and thoroughly and persistently disinfected.
With suppuration in multiple abscesses or large open sores liberal feeding must be enjoined and iron and other tonics should be resorted to.
The persistent swelling of the part must be met by active rubbing or kneading, by exercise and by uniform compression by a flannel or elastic bandage.