The rainy days combined with the hot and humid environment certainly make everyone feel a little sticky. In such an environment, what we should also beware of are some diseases that make the mind think twice. Today, we bring you perianal necrotizing fasciitis, a disease that is scary to look at by name and even scarier to initiate, right?
Concept
Necrotizing fasciitis is a soft tissue infection characterized by extensive and rapid subcutaneous tissue and fascial necrosis, often accompanied by systemic toxic shock. The disease is a mixed infection with a variety of bacteria, chief among which are aerobic bacteria such as Streptococcus pyogenes and Staphylococcus aureus. It is an important feature that the infection only damages subcutaneous tissue and fascia and does not involve muscle tissue at the site of infection.
Clinical manifestations
1.Local symptoms
The onset of the disease is rapid, and the early local signs are often insidious and do not attract the attention of the patient, but can spread to the whole limb within 24 hours.
(1) Patchy redness, pain, early skin redness and swelling, purple-red flakes, unclear boundaries, pain. At this time, the subcutaneous tissue is already necrotic, and there is rarely lymphangitis and lymphadenitis because the lymphatic pathways have been rapidly destroyed. The infection can spread to the whole limb within 24h. Individual cases may have a slow onset and be latent in the early stages. The affected skin is red or white, edematous, with marked tenderness, and the lesions are poorly defined and have a diffuse cellulitis appearance.
(2) Pain relief and numbness of the affected area Due to the stimulation of inflammatory substances and the invasion of germs, there is severe local pain in the early infection. When the sensory nerves at the site of the lesion are destroyed, the severe pain can be replaced by numbness or paresthesia, which is one of the characteristics of the disease.
(3) Bloody blisters due to the destruction of nutritive blood vessels and vascular embolism, the color of the skin gradually becomes purple and black, and blisters or large blisters containing bloody fluid appear.
(4) Strange-smelling bloody exudate with subcutaneous fat and fascial edema, viscous, cloudy, black exudate, and eventually liquefied necrosis. The exudate is a bloody plasma fluid with a peculiar odor. The necrosis spreads widely and is subterranean, sometimes producing subcutaneous gas, and examination can reveal twisted pronunciation.
2.Symptoms of systemic toxicity
In the early stage of the disease, when the local infection symptoms are still mild, the patient will have severe systemic toxic symptoms such as chill, high fever, anorexia, dehydration, impaired consciousness, hypotension, anemia, jaundice, etc. If not treated in time, diffuse intravascular coagulation and toxic shock may occur. The disproportion between the severity of local signs and systemic symptoms is the main feature of this disease.
Treatment
Necrotizing fasciitis is a critical surgical emergency, and its treatment principles are: early diagnosis, early debridement, application of a large number of effective antibiotics and systemic supportive therapy.
1.Antibiotics
Necrotizing fasciitis is a mixed infection of multiple bacteria (various aerobic and anaerobic bacteria), with early onset of systemic toxicity and severe disease, antibiotics should be applied in combination.
2.Cleaning and drainage
There is extensive vascular thrombosis in and around the lesion, and it is often difficult for drugs to reach it. Therefore, if active, high-dose antibiotic treatment does not have obvious effect for 1 to 3 days, surgery should be performed immediately. Thorough debridement and adequate drainage are the keys to successful treatment. Surgery should thoroughly remove necrotic fascia and subcutaneous tissue until the tissue cannot be separated by the fingers. Commonly used methods.
(1) Remove necrotic tissue and clean the trauma; perform free skin grafting and cover the trauma. This method can prevent a large amount of serous exudation from the trauma surface, which is conducive to maintaining the postoperative fluid and electrolyte balance.
(2) Remove necrotic fascia and adipose tissue, rinse the wound with 3% hydrogen peroxide, metronidazole solution or 0.5% to 1.5% potassium permanganate solution to create an environment unfavorable to the growth of anaerobic bacteria; then apply wet dressing with gauze soaked with antibiotic solution and change the dressing once every 4 to 6 hours. When changing the dressing, it is necessary to explore whether there is separation of skin, subcutaneous tissue and deep fascia to decide whether further expansion of drainage is needed.
(3) If the skin defect is large and difficult to heal on its own, skin grafting should be performed at an optional stage after the inflammation has subsided. The surgical operation should pay attention to the protection of healthy fascia, which is prone to the spread of infection after injury. Local wet application of metronidazole can retard skin growth and should not be applied for a long time.
3.Supportive treatment
Actively correct water and electrolyte disorders. In case of anemia and hypoproteinemia, fresh blood, albumin or plasma can be transfused; nasal feeding or intravenous high nutrition and elemental diet can be used to ensure sufficient caloric intake.