Streptococcal skin infections is a dermatological disease that is caused by highly virulent streptococci and is characterized by the development of serous inflammation without suppuration. In adults, against the background of severe intoxication in the foci of bacterial reproduction, a sluggish localized or generalized inflammatory process is observed with a sharp swelling of the affected area, rapid formation of peeling spots or bubbles surrounded by hyperemic skin. The diagnosis is made on the basis of an external examination, bacteriological examination. Treatment involves the local use of antiseptic solutions and ointments, the appointment of antibiotics, immunotherapy.
Streptococcal skin infections (streptococcal pyoderma) accounts for about 40% of all cases of pustular skin lesions. The remaining 60% are due to staphylococcal and mixed streptostaphylococcal infectious skin diseases. In 30% of cases, disease leads to temporary disability. Among adults, young women with thin skin are more likely to suffer. Streptococcal lesion is considered as an occupational disease in workers of the mining and metallurgical industries, transport and construction.
Streptococci in the folds of the skin are detected in about 12% of adults. In half of the studies, hemolytic streptococcus is detected. In smears and flushes from the throat, microorganisms of this group (in particular, greening, non–hemolytic and hemolytic) are sown in all healthy people without exception. The presence of pathogenic bacteria becomes the cause of the disease in the presence of provoking factors:
- Lack of immunity to streptococci. The genus Streptococcus includes 21 species and two dozen serogroups. Massive infection with highly virulent microorganisms can cause the development in healthy people if the immune system does not have time to recognize pathogenic bacteria and effectively suppress their reproduction.
- Violation of the barrier function of the skin. Physical and chemical effects, maceration destroy the stratum corneum. As a result, cocci freely penetrate deep into the tissues. Increased sweating, changes in the composition and amount of sebum cause a decrease in the acidity of the skin, creates conditions for uncontrolled reproduction of bacteria.
- Malfunctions of the immune system. Contact with highly virulent bacteria leads to the formation of carrier or disease in people with low levels of immunoglobulin A in the secret of the nasal mucosa. Chronic form develops as a consequence of changes affecting the components of the cellular link of immunity.
- Functional disorders of the central nervous system. Prolonged stress and fatigue in adults affect the functioning of the centers of the central nervous system. The consequence of dysfunction is a violation of the nervous and humoral regulation of a number of biological processes: trophic tissues, blood circulation, the formation of local immunity.
- Endocrinopathy. Patients with diabetes mellitus, thyroid dysfunction, and other diseases of the endocrine system are more susceptible to the development of purulent-inflammatory processes in tissues than people without concomitant pathology. In diabetes mellitus, streptococcal skin infections often takes a prolonged chronic course.
- Primary and secondary immunodeficiency. The risk of this pathology and streptostaphyloderma increases in adults who are undergoing treatment with cytostatics, immunosuppressants, glucocorticosteroids. The body’s resistance to pyococci is reduced in HIV-infected and AIDS patients.
The pathogenicity of streptococci is determined by the properties of the microbes themselves and the substances that the microbial cell releases into the external environment. These are the enzymes streptokinase and hyaluronidase, toxins. Streptococci, which belong to serogroup A, synthesize several toxic substances: O- and S-streptolysin, leukocidin, lethal, hemolytic and necrotic toxins, several variants of enterotoxins.
Through wounds, micro-injuries of the skin and mucous membranes, group A streptococci penetrate into the tissues. Bacteria bind to fibronectin molecules on the surface of human body cells. After the adhesion is completed, microorganisms begin to actively multiply, release aggression factors and protection from the human immune system into the environment.
In response to the penetration of infection, the number of neutrophils increases, there is an increased release of cytokines, activation of the complement system. The depth of the lesion is determined by the effectiveness of cellular and humoral immunity. A decrease in the phagocytic activity of neutrophils, the production of immunoglobulins A and G, indicators of the main subpopulations of T-lymphocytes underlies the transition of the acute process to a chronic form.
The onset of the disease in most cases is accompanied by a violent general reaction. Symptoms of intoxication are rapidly increasing: headaches, malaise, fever. The inflammatory process tends to be disseminated. The spread of microbial cells through the lymphatic system leads to the development of lymphangitis and lymphadenitis.
A characteristic element of a rash in adults is a non-follicular pustule or flicken. The size of the pustule is 1-2 cm, its cavity is filled with serous or serous-purulent contents. After a couple of days, the contents of the fliktena dry up into a dense yellow crust or the pustule cover breaks and exposes the eroded surface.
In place of the resolved element, a hyperemic spot remains, which eventually disappears without a trace. On the scalp and when the elements are located on the surface of the body with pronounced hairline, a temporary focus of alopecia remains in the bladder zone. The formation of atrophic and hypertrophic scars is unusual for streptococcal skin infections.
Varieties of streptococcal impetigo
Depending on the predominant localization of lesions, several variants of the course of the disease are distinguished. Slit-like impetigo is characterized by the location of the flicten at the base of the wings of the nose, in the corners and eyes. Linear cracks form in the places of the opened pustules. The elements of the rash itch, provoke the appearance of lacrimation, salivation, pain.
The tumor is manifested by the formation of pustules around the nail plates. Initially, the inflammatory process proceeds superficially, then it is possible to spread to the deep layers of the soft tissues of the phalanx. The penetration of the infection into the depth is indicated by the increase and soreness of the lymph nodes located in the area of the elbow joint.
The elements of the rash in intertriginous streptococcal skin infections are located in large folds: behind the ears, in the groin area, etc. On the face there is a dry type of impetigo – erythematous-squamous streptococcal skin infections, which is associated with skin weathering and often recurs in the off-season. The rare forms of the disease include ring-shaped and garland-like impetigo.
Generalization of the inflammatory process
A local pathological process without treatment often acquires a generalized character. A large number of rash elements with abundant exudation and the formation of grayish serous crusts appear everywhere on the skin. The red border of the lips, the mucous membranes of the mouth, nose, and eyes are affected. Diffuse foci heal with abundant peeling at the site of erosion, new vesicles and streptococcal impetigo flickens can form along the periphery.
Pyoallergids (secondary allergic rashes) are observed in 15-20% of patients with streptococcal skin infections. The features of pyoallergids are polymorphism, symmetrical location of foci. Their appearance is often accompanied by a violation of well-being, an increase in general temperature, an increase in lymph nodes. The elements may itch and itch noticeably.
The main causes of allergic rashes are considered irrational treatment using irritating ointments, warming bandages and compresses. The risk of developing pyoallergids increases in patients with liver damage, disruption of the endocrine glands. The use of immunobiological drugs in incorrectly selected dosages can provoke complications.
Examination for streptococcal skin infections is carried out by a dermatologist. An endocrinologist may be involved in the diagnosis to exclude diabetes mellitus and other diseases of the endocrine glands, a surgeon to identify chronic foci of infection. To confirm the diagnosis of streptococcal lesions and to choose a treatment, the following studies of scrapings of the affected tissues help:
- Microscopic examination. It is possible to detect staphylococci during microscopy only in cases when local and systemic antibacterial drugs were not used before scraping. The procedure is prescribed infrequently due to low information content.
- Bacteriological sowing. The method allows you to detect staphylococci or microbial associations, determine the species of microorganisms, establish their pathogenic properties and sensitivity to antibiotics. The use is limited due to the duration of the study.
Treatment of streptococcal lesions of the skin in adults is performed by conservative methods. Before the pustular rash subsides, the patient is isolated from healthy people. He is placed in the dermatological department of the hospital, where a comprehensive examination, therapy of the main and concomitant diseases are carried out. Treatment of streptococcal skin infections in adults includes:
- Skin care. Proper cleansing and antibacterial treatment reduce the likelihood of the transfer of pyogenic microorganisms to uninfected areas of the skin and the formation of new flicten. It is forbidden to wash the patient’s skin with soap and water. Healthy skin is recommended to be treated with disinfectant solutions.
- External therapy. The pustules are opened with a sterile needle, the eroded surface is treated 2-3 times a day with alcohol solutions of aniline dyes. Treatment of streptococcal skin infections involves the use of keratolytic ointments (salicylic and dermatol ointments, fucidin), drugs with antibiotics (erythromycin, tetracycline ointments).
- Antibiotic therapy. Indications for the appointment of antibacterial drugs in the treatment in adults are lymphangitis, severe intoxication, widespread deep pyoderma. The best effect is provided by therapy with macrolides, cephalosporins of I-II generations.
- Immunotherapy. Specific immunotherapy is appropriate for chronic recurrent forms of the disease. For the treatment of streptococcal skin infections, staphylococcal bacteriophage, anatoxin or antifagin is used. Prodigiozan and pyrogenal have a non-specific stimulating effect.
Prognosis and prevention
In adults who do not have immunodeficiency, endocrine and visceral pathology, the disease is cured by local means, provided proper skin care. Patients suffering from diabetes mellitus and other serious diseases of internal organs, having foci of chronic infection in the body, often develop chronic recurrent streptococcal skin infections.
Washing the skin with soap allows you to prevent the development of streptococcal skin infections. This contributes to the mechanical removal of bacteria, increasing the protective properties of the skin. In the experiment, up to 95% of bacteria died on the skin washed with soap. It is recommended to limit contact with persons suffering from pustular rash, with a preventive purpose to treat minor injuries in a timely manner.