Phlegmon

PHLEGMON (from Greek phlegmone—inflammation), diffuse inflammation of loose connective tissue. The absence of clear boundaries of the inflammatory focus in the form of granulation tissue constitutes the characteristic feature of the disease called phlegmon, in contrast to limited forms of inflammation defined as abscesses. Due to the low resistance of connective tissue to infection, its inflammatory processes, in particular phlegmon, are observed frequently. The causative agents of phlegmon are common pus-forming microbes, such as: streptococci, staphylococci, the B. coli group, etc. (see Microorganisms). Combined infections with several microbes are also not rare. Phlegmons caused by streptococci and anaerobic forms, as well as their combinations, are considered the most dangerous (see Gas phlegmon, edema). The introduction of microorganisms into the connective tissue occurs both directly during injuries (pricks and wounds) and by the spread of infection along lymphatic and blood vessels from small injuries to the integument, skin, and mucous membranes. Conditions under which the injury occurs play a large role in the occurrence of phlegmon. Thus, injuries during the autopsy of humans and animals, as well as during purulent operations, often lead to phlegmon. Among injuries at work, phlegmon complicates injuries much more often in workers dealing with animal carcasses (tanneries, canning factories, etc.), and least of all in metalworkers, especially in hot shops. In addition to superficial injuries, which as a rule entail damage to the subcutaneous tissue, phlegmons developing as a result of the transition of infection to the connective tissue from inflammatory foci located in neighboring tissues and organs are just as common. Thus, phlegmons develop on the hand and forearm from panaritium and tendovaginitis, phlegmons of the retroperitoneal space from the transition of infection from the intestine along the lymphatic and blood vessels of the mesentery, phlegmons of the mediastinum from infection during injury to the esophagus, etc. Loose connective tissue is affected by the phlegmonous process not only within one layer, but the process often spreads into the depth, into intermuscular or subfascial layers, sometimes through openings serving for the passage of vessels and nerves; in these cases, purulent melting of the connective tissue in the immediate vicinity of large vessels presents significant dangers both in terms of thrombosis and secondary hemorrhages. Phlegmons can be subdivided on the basis of various signs. The most common distinction of the inflammatory process by the nature of the exudate into serous, purulent, and putrid forms is not very satisfactory to clinicians, since serous exudate is observed only as a preliminary, often short-term initial form, and subsequently, the phlegmon passes into the usual form with purulent or putrid exudate. Rapidly clouding serous exudate does not make it possible to clearly delimit the serous form, therefore clinically, phlegmons are more often distinguished by localization: subcutaneous, subfascial, intermuscular, retroperitoneal, pelvic, retropharyngeal, etc. In addition, from a clinical point of view, phlegmons caused by anaerobic forms of microbes are distinguished. From the point of view of pathological anatomical changes in phlegmon, it is a matter of progressive acute inflammation of loose connective tissue. In exudative forms of phlegmon, attention is drawn initially to the inflammatory edema of the connective tissue, spreading evenly throughout the tissue; subsequently, as the exudate turns into pus, multiple, poorly delimited foci of necrosis of the connective tissue are usually observed. Typical for phlegmon is the involvement of the entire connective tissue within its anatomical boundaries, in contrast to abscesses, where the boundary of the inflammatory process is determined still within the limits of the given layer of connective tissue and part of it remains unaffected by inflammation. In infiltrative forms, attention is drawn to the abundant cellular infiltrate of the connective tissue, giving it a denser consistency, sometimes reaching the density of wood (ligneous phlegmons). Such phlegmons are often encountered on the neck (Reclus's phlegmons). Similar processes are observed in the pelvic connective tissue from primary lesions of the female genitalia (in the right iliac fossa), from primary lesions of the vermiform appendix, etc. The cellular infiltrate turns in places into softened foci filled with pus, sometimes multiple, sometimes single, with such a focus located in the center. In the further course, it is typical for phlegmon to have the appearance of areas of necrotic connective tissue and an increase in the foci filled with pus, both in size and in number. With a favorable course, granulation tissue develops along the edges of the process, the phlegmon turns either into a series of abscesses or into one large abscess with a further course characteristic of this form of inflammatory disease (see Abscess). In particularly unfavorable cases, delimitation does not occur, lymphangitis and thrombophlebitis join with the transition of the disease into a general form of infection with or without metastases and a very severe picture of infection, often ending in a lethal outcome. The virulence of microorganisms, their type, localization, and the nature of the disease or injury that is the source of the phlegmon play a role in the development of the process. Clinically, phlegmon in its typical initial stages is characterized by rapidly spreading, sharply painful inflammatory swelling, almost always simultaneously with general symptoms, such as an increase in temperature and phenomena of intoxication. If it is a question of superficially located phlegmons, then simultaneously an inflammatory redness without sharp boundaries and edema of the tissues appear. The skin looks tense, acquires a certain shine, natural depressions are smoothed out, and phenomena of lymphangitis in the form of typical red stripes or damage to veins (thrombophlebitis) are also often determined. With deeply located phlegmons, inflammatory swelling and edema manifest as an increase in the volume of the affected area or a palpable, diffuse, sharply painful infiltrate with vaguely defined boundaries. Both with superficial and deep localizations, regional lymph nodes swell and become painful. General phenomena in deep forms often come to the fore. Fever often begins suddenly, after a more or less sharply manifesting chill, the temperature reaches a significant height (39°) and takes on a constant character. The remissions observed in the further course serve either as a sign of the development of purulent accumulations or, in a severe general condition and shaking chills, serve as one of the signs of the transition of the process into a general purulent or putrid infection. In the further course, the development of the process can result either in a more favorable form, with increasingly manifesting signs of localization of the process, or in a more dangerous, progressive form, which, being left to its own course, entails a transition into a general infection without any signs of localization. With a form inclined to delimitation, the gradual formation of granulation tissue occurs around the foci of necrotic connective tissue, and in the final outcome, one or several foci, becoming completely delimited, thus turn into abscesses, which are then opened. Clinically, this is manifested by the development of foci of softening, determined by fluctuation. Sometimes, however, the latter sign is difficult to establish against the background of general tissue edema. With superficial location, such a focus or foci, if they are multiple, correspond to the most intense redness, which then acquires a cyanotic shade, the skin thins, and finally, the focus empties outward. Corresponding to the delimitation and especially the opening of the foci and their emptying of pus, the general condition improves, the temperature drops, the abscesses are gradually filled with granulations and close. However, in view of the prevalence of the process and the extremely irregular form of connective tissue lesions, subsequent formation of new foci, tracking, etc., is not rare, which delays healing and creates a threat of new spread of the inflammatory process in the connective tissue. Enlarged regional lymph nodes can also soften with the formation of purulent foci. The progressive form usually does not give any signs of stopping the course of inflammation without surgical intervention, except for randomly arising areas of granulations, which are completely insufficient to localize the process; the inflammatory edema spreads rapidly, capturing the connective tissue over a very large extent, for example, the entire limb, the entire mediastinum, etc. Such phlegmons easily pass from superficial connective tissue to subfascial and intermuscular. Phenomena of edema entail a significant increase in the volume of the affected area, redness and pastiness are determined on the skin. General phenomena are very violent, phenomena of intoxication depending on the nature of the toxins are very bright, the temperature is high and constant. This form of phlegmon is very dangerous and, without early energetic intervention, usually leads to death.

Besides these main forms, there are also mild forms of phlegmon, where all phenomena are limited only to the initial stage and do not reach the point of necrosis and suppuration; this form can be considered as a violent inflammatory reaction of the cellular tissue around some separate focus (puncture wound, tenosynovitis, etc.). Elimination of the infection in the main focus leads to a rapid subsidence of the inflammatory process. All these signs make the diagnosis of phlegmon usually not difficult. In practice, phlegmons arising as a result of other diseases are not rare. Thus, perforation of the esophagus into the mediastinum causes diffuse purulent mediastinitis, perforation of the vermiform appendix in its posterior position can cause retroperitoneal phlegmon, etc. In both cases, phlegmonous inflammation only imparts a special character to the main ailment and does not change the diagnosis. The prognosis for phlegmon depends on the type and virulence of the microbes, the source of infection, and the localization of the process. The deeper and more extensive the spread of the process, and the less the tendency to demarcation, the more serious the prognosis. The timeliness of surgical intervention is also of great importance. In addition to the danger to life, phlegmons often entail persistent functional disorders, especially in the limbs regarding the mobility of the fingers, subsequent pain, and suffering of the musculature and joints of the affected areas. Treatment of phlegmon consists of early surgical intervention. An exception may be made only for very mild forms of inflammatory reaction of the cellular tissue, where it is possible to manage with conservative measures in the form of warming compresses, in particular alcohol ones, hot baths, i.e., measures that cause hyperemia, while simultaneously keeping the diseased area at rest, which on the limbs is achieved by splint dressings. These same measures can be applied in the initial stages, up to 48 hours, but once foci of necrosis have formed and purulent exudate has developed, even in the form of tissue infiltration, incisions are indicated. The latter should be performed under anesthesia (ether). The use of a tourniquet is undesirable. Incisions are made at the sites of softening, taking into account the anatomical features of the region for convenient outflow of pus; counter-openings are often necessary. In most cases, it is necessary to make several incisions, which also proves to be more advantageous in subsequent treatment. In superficial phlegmons, after incisions, it is permissible to carry out tampon-free treatment where good outflow of discharge is achieved; otherwise, spreader tampons are indicated to prevent the closure of wound edges. Immobilization of the limb is mandatory even after incisions are made until the wounds are completely demarcated by granulations; bed rest is mandatory until a stable drop in temperature. In general, any kind of trauma to the inflamed areas can entail a new flare-up and spread of the process; therefore, dressing changes must be very careful and gentle with respect to the developing granulations. If pockets with stagnant pus or new foci are subsequently discovered, new incisions or counter-openings are indicated. Where tampons were present, they should be removed with particular care and tamponade should be stopped as soon as possible; tampons near tendons are especially undesirable. In deep phlegmons, wide opening of the affected area is indicated, taking into account anatomical relationships, remembering that dense fasciae often serve as natural boundaries of the process; they should be dissected only to open already affected areas. In deep forms, it is possible to manage without loose tamponade only with a particularly favorable arrangement of the incision for the outflow of pus. Tamponade continues until the cavity is filled. The initial tampons are changed after the formation of a granulation cover, for which one should not rush (4-5 days). The wound edges during the change of tampons are spread with blunt hooks both during removal and during insertion of the tampon. Along with changing dressings, active hyperemia is also indicated in the postoperative period, for which hot baths serve as an excellent means, where they are applicable. During dressings, whole sections of necrotic cellular tissue are often released along with the pus; they are removed with tweezers after they have separated from the surrounding tissue or are cut off with scissors, but within the limits of the still necrotic tissue without traumatizing the granulations demarcating the focus. In severe forms of phlegmon, general treatment against infection is simultaneously conducted (see Sepsis); blood transfusion from immunized donors deserves special mention. In phlegmon of the neck with woody infiltrate, one should not wait for softening, but make incisions, not being embarrassed by the fact that pus does not initially drain from them.

Among the complications of phlegmon, one should first of all point out the already mentioned possibility of transition into a general purulent infection; furthermore, thrombophlebitis, lymphangitis, and lymphadenitis are not rare as concomitant phenomena. From here, metastases of the infection are possible even to more distant regions, in particular to the lungs with the development of pneumonia. In phlegmon of the head and face, there is a real danger of meningitis from the transition of the process along the veins; in phlegmon of the limbs with necrosis of the cellular tissue surrounding large vessels over a large extent, secondary hemorrhages are dangerous; furthermore, contractures of the fingers, limitation of their mobility up to complete loss, cicatricial contractures of joints, etc., can easily arise; in phlegmon of the neck, edema of the glottis is especially dangerous. In those cases where a tendon becomes necrotic or a muscle dies simultaneously with the cellular tissue, it is necessary to timely warn the patient about subsequent functional disorders. Upon the development of demarcation and a complete drop in temperature, one should cautiously resort to early movements to prevent disorders of motor functions. Involvement of nerves in scars can cause pain, disorders of movement and trophics, and require subsequent interventions for neurolysis. In the presence of large granulation surfaces, it is necessary to timely resort to transplantation according to Thiersch or Davis. Plastic surgeries to restore functional disorders, due to fears of latent infection in the scars, should be performed no earlier than 6-8 months after healing and after preliminary testing of provocative measures. S. Girgolav.