Phlegmon is a spreading diffuse inflammatory

Inflammation

Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...

 process with formation of suppurative/purulent exudate

Exudate

An exudate is any fluid that filters from the circulatory system into lesions or areas of inflammation. It can apply to plants as well as animals. Its composition varies but generally includes water and the dissolved solutes of the main circulatory fluid such as sap or blood...

 or pus

Pus

Pus is a viscous exudate, typically whitish-yellow, yellow, or yellow-brown, formed at the site of inflammatory during infection. An accumulation of pus in an enclosed tissue space is known as an abscess, whereas a visible collection of pus within or beneath the epidermis is known as a pustule or...

. This is the result of acute purulent inflammation which is due to bacterial infection.

An example would be phlegmon of diverticulitis. In this case a patient would present to the emergency department with left lower quadrant abdominal tenderness, and the diagnosis of sigmoid diverticulitis would be high on the differential diagnosis, yet the best test to confirm it would be CT scan.
Another example, phlegmon affecting the spine, is known as spondylodiscitis

Spondylodiscitis

Spondylodiscitis is a combination of discitis and spondylitis , the latter generally involving the areas adjacent to the intervertebral disc space.-Causes:...

 and is associated with loss of disc height and endplate destruction. In adults, the bone marrow

Bone marrow

Bone marrow is the flexible tissue found in the interior of bones. In humans, bone marrow in large bones produces new blood cells. On average, bone marrow constitutes 4% of the total body mass of humans; in adults weighing 65 kg , bone marrow accounts for approximately 2.6 kg...

 is affected first, while in children, the disease starts in the disc itself and spreads rapidly to the adjacent vertebral bodies. Phlegmon in the spine can be a diffuse enhancement, or localized abscess, (peripheral enhancement) in the epidural, subligamentous or paraspinous spaces. Under MRI examination, phlegmon will show dark with T1, and high signal (bright) with T2.

Etiology

Commonly by bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 - streptococci, spore and non-spore forming anaerobes, etc.

Factors affecting the development of phlegmons are virulence of bacteria and immunity strength.

Classifications

1. By clinical course:
   • acute
   • subacute
2. By severity of condition:
   • mild
   • average
   • severe (with spreading to other location(s))
3. By location:
   • Superficial
     • cutaneous
     • subcutaneous
     • interstitial tissue
     • intramuscular
   • Deep
     • mediastinal
     • retroperitoneal
4. By etiology:
   • single
   • mix (eg:spore and non-spore forming anaerobes)
5. By pathogenesis:
   • per continuitatem (through neighbouring tissues)
   • hematogenous (through non-valvular veins like venous plexus of face eg: v. pterygoideus plexus → inflammation of veins (phlebitis
     Phlebitis
     Phlebitis is an inflammation of a vein, usually in the legs.When phlebitis is associated with the formation of blood clots , usually in the deep veins of the legs, the condition is called thrombophlebitis...
     
     ) → thrombus formation in veins → embolization of thrombus into sinus venousus systems)
   • odontogenous
6. By exudative character:
   • purulent phlegmon
   • purulent-hemorrhagic phlegmon
   • putrefactive phlegmon
7. By presence of complications:
   • with complications (disturbance of mastication, ingestion, speech, cardiovascular and respiratory system, peritonitis, lymphadenitis, loss of conscious if very severe, etc)
   • without complication

Clinical pictures

1. Systemic features of infection such as increased body temperature (up to 38-40 °C), general fatigue, chills, sweatings, headache, loss of appetite).
2. Inflammatory signs - dolor
   Dolor
   Dolor may refer to:* Pain* Suffering* The unit of measurement in utilitarianism, see Felicific calculus#Hedons and dolors...
   
    (localized pain), calor
   Calor
   Calor Gas is a brand of bottled butane and propane which is available in Britain and Ireland. It comes in cylinders, which have a special gas regulator.Calor was formed in 1935. Calor is the UK's leading supplier of Liquefied petroleum gas...
   
    (increase local tissue temperature), rubor (skin redness/hyperemia), tumor
   Tumor
   A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...
   
    (either clear or non-clear bordered tissue swelling), functio laesa
   Functio laesa
   Functio laesa is a term used in medicine to refer to a loss of function or a disturbance of function.It was identified as the fifth sign of acute inflammation by Galen, who added it to the four signs identified by Celsus ....
   
    (diminish affected function).

NB: severity of patient condition with phlegmons is directly proportional to the degree of intoxication level i.e the severe the condition, the higher degree of intoxication level.

A noninfectious occurrence of phlegmon be found in the acute pancreatitis of Systemic Lupus Erythamatosis. The immunosuppressive aspects of this disease and the immunosuppressive medications used to treat it blunt each of the signs of infection.

Diagnostics

1. Complaints and clinical appearances
2. Anamnesis
3. Visual and Palpations
4. Blood test - leukocytosis
   Leukocytosis
   Leukocytosis is a raised white blood cell count above the normal range in the blood. It is frequently a sign of an inflammatory response, most commonly the result of infection, and is observed in certain parasitic infections...
   
   (up to 10-12×10⁹/L), decrease or absence eosinophils level, shift of white count differential to the left (neutrophilia), increase ESR (up to 35–40 mm/hr).
5. Urine test - presence of bacteria in urine, increase urinary leucocyte counts.
6. X-ray test
7. Ultrasound test

Treatments

The main goal of treatment is to remove the cause of the phlegmonous process in order to achieve effective treatment and prevention of residives.

If the patient's condition is mild and signs of inflammatory process are present without signs of infiltrates, then conservative treatment with antibiotics is sufficient.

If the patient's condition is severe, however, immediate operation is usually necessary with application of drainage system. All of these are done under general anaesthesia. During operation, the cavity or place of phlegmonous process are washed with antiseptic, antibiotic solutions and proteolyic ferments.

In post-operative period, patients are treated with intravenous antibiotics, haemosorbtion, vitaminotherapy. Additionally, the use of i/v or i/m antistaphylococci γ-globulin or anatoxin can be taken as immunotherapy.

During operation of phlegmon dissection at any location, it is important:

1. to avoid spreading of pus during operation;
2. to take into account the cosmetic value of the operating site, especially when treating phlegmmonous process of the face; and
3. to avoid damaging nerves.