Dry and moist gangrene of the toes in diabetes mellitus

One of the serious problems associated with chronic hyperglycemia (high blood sugar) is diabetic gangrene, which occurs in patients with this metabolic disease due to poor blood supply to tissues and deterioration of their trophism.

Epidemiology

According to WHO statistics, the average prevalence of diabetes in the world has reached 6.3% (in North America it is twice as high) and continues to increase. [ 1 ], [ 2 ]

Every year, trophic ulcers and tissue necrosis caused by diabetes occur in 2-5% of patients, and the risk of these complications of chronic hyperglycemia is estimated at 15-20%.

Approximately every third patient eventually develops diabetic foot syndrome, and the result of its absence of treatment is gangrene of the foot in diabetes. In almost 85% of cases, it ends in amputation of the limb, and in 5.5% of cases – death. [ 3 ]

According to surgeons, today 60-70% of all lower limb amputation surgeries are associated with diabetes.

Causes diabetic gangrene

Experts note the following underlying causes leading to tissue death – gangrene – in patients with diabetes:

• vascular damage - diabetic angiopathy of the lower extremities, that is, a violation of peripheral circulation with a limitation of blood flow to the distal parts of the extremities and local tissue ischemia. This negatively affects the wound healing process, slowing down the natural regeneration of damaged cells, reducing the rate of re-epithelialization and restoration of anatomical integrity even with the most minor wounds; [ 4 ]
• diabetic neuropathy – damage to sensitive nerve fibers, as a result of which the transmission of nerve impulses is disrupted and sensitivity and/or pain sensation is lost. Thus, the prerequisites for unnoticed injuries (cuts, abrasions, scratches, etc.) and the progression of developing inflammation arise. [ 5 ]

The presence of chronic lesions of blood vessels and nerve fibers causes gangrene of the lower extremities in diabetes, and most often this is gangrene of the foot or gangrene of the fingers (toes or hands).

In addition, hyperglycemia negatively affects local immunity, reducing the response of immunocompetent cells to infections and their protective functions. [ 6 ]

Risk factors

The absolute risk factors for the development of gangrene in patients with diabetes include:

• mechanical damage (trauma) to the skin and soft tissues;
• trophic ulcers in diabetes on the legs;
• accompanied by infection of the ulceration of the skin and subcutaneous tissue, alteration of connective tissue joint structures and bone tissue on the foot, called diabetic foot, when the pathological process reaches stages 4-5 of development.

There is information that the drugs Canagliflozin and Dapagliflozin, which reduce blood sugar levels (by blocking protein compounds that transport glucose into the blood), increase the likelihood of developing gangrene of the anogenital area - Fournier's gangrene. Its symptoms can include fatigue and fever, as well as swelling and redness of the skin in the genital area. As experts note, this type of gangrene is rare and can occur in diabetics with insufficient fluid intake and functional kidney failure due to a urinary tract infection. [ 7 ]

Pathogenesis

Gangrene is tissue necrosis due to the cessation of their blood supply, in many cases with infection of the area of skin integrity damage by bacteria that cause inflammation, in particular, Staphylococcus aureus (golden staphylococcus), Streptococcus pyogenes (β-hemolytic streptococcus), Pseudomonas aeruginosa (Pseudomonas aeruginosa), Proteus mirabilis (Proteus), etc.

The pathogenesis of tissue necrosis caused by them is discussed in detail in the material – Gangrene.

Explaining the mechanism of gangrene development in diabetes, doctors emphasize that in this endocrine disease - with its specific metabolic disorders - the expression of proinflammatory cytokines is increased, but the main phases of the normal healing process are slowed down. And this leads to non-healing trophic ulcers in diabetes, which often become infected with complications in the form of abscesses and gangrene.

Symptoms diabetic gangrene

How does gangrene begin in diabetes? It directly depends on its type, since gangrene can be dry, wet and anaerobic (gas).

Most often, the toes are affected by dry gangrene in diabetes - without the participation of bacteria, caused by tissue ischemia and developing in the form of their coagulative necrosis. Its first signs are numbness, tingling and a decrease in local skin temperature (the affected area of the limb becomes cold and pale due to the outflow of blood). Then severe pain occurs in the depths of the affected area, which turns into a brown-green ulcer with rapidly blackening skin along the edge. [ 8 ], [ 9 ]

The symptoms of wet gangrene of the legs associated with a bacterial infection in diabetes essentially demonstrate all the characteristic signs of colliquative (melting) necrosis developing in the tissues - with swelling and redness of the skin, bleeding and pain (with subsequent loss of sensitivity), as well as rapid loosening of the tissues, which become a very unusual color (from grayish-green to purple-red) with a putrid odor. The body temperature rises. At one of the stages of tissue necrosis, a scab forms on the surface, under which pus can accumulate, and when the crust cracks, it pours out. [ 10 ]

When tissues are affected by an anaerobic infection, primarily clostridia (Clostridium septicum, Clostridium perfringens, etc.), gas gangrene develops in diabetes, and at the initial stage the patient begins to feel heaviness, swelling, and bursting pain in the affected limb. All the details about its features and symptoms are in the publication - Gas gangrene.

How gangrene of the lower extremities occurs and how it is treated in diabetes, see the publication – Gangrene of the leg.

Complications and consequences

Complications of dry gangrene include its infection and transformation into wet gangrene, as well as spontaneous amputation of the affected part of the limb (due to rejection of dead tissue).

The most serious consequences of wet and gas gangrene are general intoxication of the body and sepsis.

Diagnostics diabetic gangrene

Diagnosis begins with an examination of the lesion and the patient's history.

The following tests are required: general and biochemical blood tests; blood glucose levels; bacteriological culture of purulent exudate; antibiotic sensitivity test.

To assess tissue viability and the possibility of restoring limb vessels, instrumental diagnostics are used: X-ray and ultrasound of soft tissues in the affected area, ultrasound duplex scanning of vessels, ultrasound Dopplerography and sphygmomanometry, radioisotope scintigraphy. [ 11 ]

Differential diagnosis

Differential diagnosis of diabetic gangrene includes abscess, inflammation in phlebothrombosis or embolism of the arteries of the lower extremities, pyoderma, as well as necrosis in erysipelas or streptococcal lesions of muscle tissue.

Treatment diabetic gangrene

Treatment of diabetic gangrene can be carried out if it is detected in the early stages. The main drugs used for gangrene are broad-spectrum antibiotics, that is, capable of affecting most bacteria that can cause tissue inflammation with subsequent necrosis. Amoxiclav, Ampiillin + Clindamycin, Carbenicillin, Amikacin, cephalosporins ( Cefazolin, Ceftriaxone, etc.), Metronidazole or Vancomycin are used by injection. [ 12 ]

To treat the affected area and dressings, use a solution of Dioxidine, an ointment with an antibiotic (Baneocin, Levosin, Levomekol ).

If the gangrene is gaseous and accompanied by intoxication, an antitoxic anti-gangrenous serum is administered intramuscularly.

Physiotherapeutic treatment is possible using the hyperbaric oxygenation method, which – by improving the supply of oxygen to damaged cells – stimulates tissue healing and regeneration.

Experts consider herbal treatment to be ineffective in cases of gangrene, and only in the mildest forms is it allowed as an auxiliary remedy, for example, in the form of washing and irrigating damaged areas with decoctions of St. John's wort, calendula, arnica, plantain, chamomile, thyme or rosemary.

In almost all cases, surgical treatment is required. First of all, sanitation is performed – removal of the affected tissue, after which reconstructive surgery is possible, during which the affected area of the limb is closed using a skin flap transplant. [ 13 ]

In case of dry gangrene, they resort to vascular surgery: they restore blood flow in the affected area, that is, they perform revascularization – stenting or transplantation of part of a healthy vessel. [ 14 ]

When progressive gangrene in diabetes has reached a late stage, a decision is made about the need to amputate the affected part of the limb.

Prevention

To avoid gangrene, it is necessary to control blood sugar levels with an appropriate diet and adequate treatment of diabetes and all its complications, read more:

• Treatment of trophic ulcers on the legs in diabetes mellitus
• Treatment of diabetic foot

According to endocrinologists, it is important that every diabetic patient is aware of the nature of this disease and its possible consequences. [ 15 ]

For diabetic foot, experts recommend the following preventive measures: keep your feet clean and trim your nails regularly; wear comfortable shoes (that do not rub or press anywhere), inspect your feet every day (to check for the presence/absence of any damage or change in skin color).

Forecast

Patients with dry gangrene (not associated with a bacterial infection) have a fairly good chance of a successful outcome.

And the prognosis for wet and gas gangrene in diabetes is not very favorable due to the risk of sepsis. Mortality in patients with diabetes with foot gangrene ranges from 6-35%.