Deep pyoderma is a group of purulent-inflammatory lesions of the skin (mainly its deep layers – the dermis) caused by infection of tissues with staphylococci, streptococci or mixed microflora. The symptoms of the disease vary depending on the severity of inflammation and the nature of the pathogen, but necessarily include swelling, soreness, redness and pus formation. Diagnosis of deep pyoderma is based on external skin manifestations and microbiological studies to identify the pathogen. Surgical techniques are widely used in the treatment to ensure the outflow of pus, local and general antibiotics, antimicrobial and antiseptic agents.
Deep pyoderma is a purulent disease of the skin, a feature of which is the lesion of the dermis, subcutaneous tissue, deeply located hair follicles, sweat and sebaceous glands. This condition is one of the most common pathologies in dermatology – according to various sources, it accounts for from 30 to 40% of all dermatological diseases. Almost every person has suffered from manifestations of various forms of deep pyoderma at least several times in his life. This is due to the high prevalence of pathogens (staphylococci and streptococci), their virulence, and a huge variety of strains. In most cases, deep pyoderma does not threaten human life and is even cured independently without special therapy, but sometimes it can be the cause of intoxication, a source of metastatic purulent foci and even the cause of sepsis.
In broad terms, deep pyoderma is a skin lesion caused by a purulent microflora, which includes staphylococci, streptococci, Pseudomonas aeruginosa and some other microorganisms. However, more than 95% of cases of the disease are caused by coccoid flora, since it is widespread in the environment and is partly represented even on the surface of the skin of a healthy person. When penetrating into the skin tissue through microcracks, damage to the epidermis, along the hair rods and along the ducts of the skin glands, microorganisms begin to multiply rapidly. The enzymes and various toxins released by them in the process of vital activity cause the destruction of skin cells. As a result of these processes, a primary focus is formed, located in the dermis – there are no symptoms of deep pyoderma at this stage.
The microorganisms themselves and the enzymes they secrete have strong immunogenic properties, therefore, almost immediately after the formation of the primary focus, an immediate reaction of the immune system occurs. Traditionally, tissue macrophages are the first to react to infection, then neutrophils enter the future focus of deep pyoderma by chemotaxis, and then other immunocompetent cells. The biologically active substances released by them lead to local swelling, redness, and the appearance of painful sensations. Clinically, this corresponds to the first stage of deep pyoderma – the formation of an inflammatory focus, which may tend to expand.
At a certain stage, the immune system manages to localize the inflammation, and its spread in the tissues stops. Neutrophils attack pathogenic microorganisms and partly their own tissues (secondary alteration) in the focus with the formation of pus – a substance consisting of “fragments” of pathogens, destroyed own cells and dead neutrophils. The development of deep pyoderma is facilitated under a number of circumstances – reduced immunity, diabetes mellitus, exhaustion, hypovitaminosis and other conditions that weaken the body. An important role is played by neglect of the rules of personal hygiene, excessive production of sebum, local hypothermia of the skin. For people with reduced immunity, deep pyoderma is dangerous because it can cause severe lesions, cause various complications, some of which can directly threaten human life.
There are several clinical varieties of deep pyoderma, which are characterized by different pathogens, the severity of symptoms and the type of affected tissues. All forms of this disease by the nature of the microflora that caused inflammation are divided into staphyloderma, streptoderma and mixed varieties, which are sometimes called streptostaphyloderma. Deep pyoderma caused by staphylococci include boils, carbuncles, hydradenitis and deep folliculitis. Deep streptodermia are represented by vulgar ecthyma, and inflammation due to mixed microflora is represented by chronic ulcerative vegetative pyoderma.
Furuncle is a type of deep pyoderma, a feature of which is the lesion of the hair follicle of a purulent–necrotic nature with a transition to the surrounding tissues. Its development may be preceded by superficial purulent inflammation (folliculitis), but the primary development of a deep process is also possible. On the area of the skin surrounding the hair, a crimson focus is formed first, ranging in size from a few millimeters to 1-2 centimeters, painful and dense, its temperature is noticeably higher than the surrounding skin. Then deep pyoderma of this type is accompanied by the appearance of pus, in the center of which there will be a rod of necrotic tissue. The purulent-necrotic contents are rejected after 3-10 days, a small ulcer forms at the site of the skin lesion, which quickly scars.
Carbuncle is a more severe type of deep pyoderma caused by staphylococcal flora and characterized by damage to the deep layers of the dermis and subcutaneous fat. A dense infiltration occurs in the depth of the skin, the skin above it acquires a bluish-purple hue, becomes hot and painful. After a few days, pustules begin to form in the focus of deep pyoderma, pus and necrotic rods are released, an ulcer forms at the site of the lesion. All this is accompanied by pronounced general symptoms – intoxication, fever, shooting pains at the site of the carbuncle. Regional lymphadenitis and lymphangitis are noted. After the resolution of this form of deep pyoderma, a noticeable scar remains at the site of the lesion.
Hydradenitis is a form of deep pyoderma, in which apocrine sweat glands are affected with the development of purulent inflammation. Because of this, the characteristic localization of pathological foci is axillary cavities, periarticular and anogenital areas. Hydradenitis begins with the development of a painful cyanotic node, which increases significantly in size in a few days and spontaneously opens with the release of copious amounts of pus. Then there is a gradual healing, scars are formed in extremely rare cases. With this form of deep pyoderma, regional lymphadenitis and lymphangitis are also noted, but the general symptoms are poorly expressed. Hydradenitis, especially in the armpits, is prone to frequent relapses.
Deep folliculitis is one of the mildest forms of deep pyoderma, which differs from ordinary folliculitis by a more pronounced lesion of the hair follicles. The symptoms are generally similar to a boil, but the manifestations are less pronounced, common symptoms are almost never observed. The main diagnostic criterion that allows a dermatologist to distinguish a boil from a deep folliculitis is the absence of purulent–necrotic inflammation, since a characteristic necrotic rod is not formed.
Vulgar ecthyma is a form of deep pyoderma caused by streptococcal microflora. Most often affects the skin of the lower leg in weakened patients, in extremely rare cases occurs in healthy people. Ectima begins with the formation of a pustule on the surface of the skin with cloudy contents of a serous, sometimes hemorrhagic nature. Then the pustule disappears and in its place a typical focus of deep pyoderma is formed – a painful ulcer with a pronounced inflammatory rim around, the bottom of the formation is covered with a layer of pus. 2-3 weeks after the appearance of the ulcer, its gradual scarring begins with the development of a noticeable scar.
Chronic ulcerative-vegetative pyoderma is a skin disease, the causative agents of which are mixed microflora, the greatest role in the development of pathology is played by Staphylococcus aureus and streptococci of group A. Deep pyoderma of this type most often develops in weakened patients – emaciated persons suffering from alcoholism, the elderly. It is characterized by the formation of irregularly shaped erosions on the lower extremities with ragged edges surrounded by inflamed skin. The bottom of ulcerative formations is covered with pus, often there is a discharge with an unpleasant fetid smell. Erosions do not heal for a long time and are prone to frequent relapses or damage to other areas of the skin.
Complications of any kind of deep pyoderma can be metastatic purulent lesions of regional lymph nodes and distant organs. Especially dangerous in this regard are deep folliculitis and boils that occur within the nasolabial triangle – the anastomoses of blood vessels present there contribute to the introduction of infection into the brain and its membranes. In weakened patients against the background of deep pyoderma, phlegmons and sepsis may occur, which are life-threatening conditions. In rare cases, toxic shock may develop.
Diagnosis of various forms of deep pyoderma is carried out by examining a dermatologist (sometimes a surgeon’s consultation may be required). Of the additional research methods, pus sowing is most often used to determine the nature of the pathogen and to determine its sensitivity to antibacterial agents. With the development of common symptoms, it is also necessary in some cases to conduct a general blood test, in the most severe cases – blood backfeed for the diagnosis of sepsis. The results of the examination depend on the form of deep pyoderma and the stage of its development – it may simply be an inflammatory focus, an abscess formed, a wound or an ulcer with a purulent discharge. When sowing, staphylococci or streptococci are detected, mixed microflora may be detected. Microbiological studies of crops can determine the type and strain of the pathogen, as well as its sensitivity to antibiotics.
If there is an increase in temperature, headache, weakness, then a general blood test is necessary. Usually, with deep pyoderma, mild nonspecific signs of inflammation are detected – an increase in the rate of erythrocyte sedimentation, a small leukocytosis. In more severe cases, already pronounced changes are observed – a significant increase in ESR, pronounced leukocytosis, changes in the distribution of neutrophils are detected. A lot of young forms of this fraction of leukocytes appear in the blood, which is called neutrophil shift to the left. If there is a suspicion that deep pyoderma has caused sepsis, blood is seeded on nutrient media – normally human blood is absolutely sterile, the growth of cultures indicates the presence of a pathogen in the blood. Ultrasound, X-ray and other clinical research methods can be used to diagnose complications such as metastatic purulent foci.
With minor purulent lesions without general manifestations of intoxication, it is recommended to wait for spontaneous resolution of deep pyoderma. Therapeutic measures are reduced to preventing complications. If there is hair around the purulent focus, they need to be carefully cut off – using a razor can lead to the spread of infection. It is not recommended to wash the area with a focus of deep pyoderma, it is permissible only to wipe the skin around it with disinfectant solutions (chlorhexidine, salicylic acid solution). It is strictly forbidden to open an abscess independently without the participation of a dermatologist or surgeon or to accelerate the separation of pus in any way – this can lead to the dissemination of the pathogen.
If deep pyoderma is characterized by the development of large foci with the appearance of common symptoms (fever, weakness, headaches), then it is necessary to prescribe antibacterial agents such as erythromycin, tetracycline, lincomycin – it is desirable to make a bacterial culture beforehand and determine the drug to which this microorganism is most sensitive. Also, antimicrobial agents from the group of sulfonamides are used for deep pyoderma, for example, sulfamethoxazole + trimethoprim. In recent years, in severe cases of purulent skin lesions, immunological preparations have also been used – staphylococcal toxoid, antistaphylococcal hyperimmune plasma and a number of others.
With a deep location of a significant pyoderma focus, surgical opening of the abscess cavity is resorted to to form drainage and outflow of pus. In addition, it allows you to deliver antiseptic and antibacterial drugs directly to the affected area, which accelerates treatment. The opening of the focus of deep pyoderma should take place in a sterile room and be carried out by a qualified purulent surgeon.
Prognosis and prevention
In most cases, the prognosis for the development of various forms of deep pyoderma is favorable – after the separation of pus, the focus heals, quite often with the formation of scars. However, weakened patients with a low level of immunity may develop complications, some of which may be life-threatening and require treatment in a hospital setting. To prevent the development of deep pyoderma, it is necessary to adhere to the rules of personal hygiene, timely treat skin lesions (abrasions, cuts) with antiseptics. In addition, it is important to eliminate possible sources of infection in the body – carious teeth, chronic infections of the ENT organs.