Impetigo is a group of superficial pyoderma of infectious origin. The clinical manifestations of the disease correspond to the impetigo variety, but they also have common features: the debut is characterized by the appearance of erythema, against which vesicles with serous-purulent contents pour out, resolved by the formation of honey-yellow crusts. Over time, the crusts disappear, leaving a slight depigmentation or hyperpigmentation, disappearing without a trace. Sometimes itching occurs, leading to scratching with the outcome in hemorrhagic crusts. Impetigo is diagnosed clinically, dermatoscopically, and the pathogen is determined by seeding the contents of the pustules. The treatment is antibacterial, restorative.
Impetigo is a set of infectious pustular diseases of the surface layers of the skin caused by streptococci and staphylococci, which account for more than 15% of all skin pathology. Each of the surface pyoderma has its own characteristics. Streptococcal impetigo is endemic to areas with warm, humid climates. It differs seasonally: the peak of morbidity is the end of summer. There is no asymptomatic carrier. The microbe gets on healthy skin from the outside due to non-compliance with the rules of personal hygiene, immediately provokes the development of the disease.
Staphylococcal impetigo is characterized by the greatest potential pathogenicity, while staphylococcus can be on the skin for a long time at the stage of a latent infectious process without clinical manifestations. As a result, impetigo is diagnosed both in the form of sporadic cases of the disease that do not go beyond one family or labor collective, and in the form of epidemiological outbreaks in newborns (epidemiological pemphigus). Such cases can be caused by both staphylococcus itself and its exotoxin, they require the closure of the maternity hospital for quarantine with total disinfection to prevent the dissemination of the process. Similar epidemics are possible in schools, barracks. Taking into account the asymptomatic carrier, in case of detection of staphylococcus in one patient, treatment is carried out to all persons in contact with him, regardless of clinical manifestations.
The cause of impetigo is obvious – coccal flora, widespread in nature. A large number of staphylococci and streptococci are constantly present on the skin. These are representatives of the so-called transient flora, capable of infecting the skin without even multiplying on its surface. The latency of their existence is due to the protective function of the skin. In case of violation of the integrity of the skin as a result of trauma, maceration (swelling of the dermis with prolonged contact with fluid), dysfunction of the sweat and sebaceous glands, changes in the normal acidity of the skin, the entrance gate opens for the penetration of infection. This moment is aggravated by a violation of the rules of personal hygiene, a decrease in immunity.
Then, inflammation develops in the dermis, aimed at destroying the infectious antigen with the restoration of the skin defect. Inflammation begins at the site of connective tissue – histione, consists of phases of alteration, exudation, proliferation. Alteration is the release of inflammatory mediators into the skin from damaged cells. Mediators include phagocytosis, increase the permeability of the vascular wall, begin to disinfect the site of inflammation due to bactericidal properties. In addition, they cause secondary alteration (histolysis), connect immune mechanisms to inflammation, regulate proliferation due to the work of macrophages. Moreover, this whole process operates on the principle of feedback. The exudation phase occurs almost instantly after the alteration, includes a number of processes: changes the viscosity of blood, increases the permeability of capillaries, causing the migration of blood components into the focus of inflammation with the formation of exudate, inflammatory cellular infiltrate. Proliferation completes the process. As a result of the sequential implementation of all phases of inflammation, the skin is completely restored or scarred (depending on the size and depth of the initial defect).
In dermatology, it is customary to classify impetigo depending on the cause of the disease and clinical manifestations. There are:
1. Streptococcal (contagious) impetigo: the cause of occurrence is streptococcus, which more often affects the skin of children and women. A very common and contagious form of impetigo. It includes several varieties:
- simple lichen (“dry” pyoderma) – occurs in children on the face, is considered an abortive form. It is manifested clinically by erythematous pink spots with peeling. The elements resolve under the influence of the sun, leaving persistent depigmentation;
- annular impetigo – a feature of pathology is the formation of bullae, which resolve in the central part with the formation of crusts, and continue to grow along the perimeter, forming an element resembling a ring;
- bullous impetigo is the most dangerous type of the disease. A distinctive feature is the rash of bullae with purulent-hemorrhagic contents up to 2 cm in diameter, mainly on the extremities. Flickens grow, open, forming “fatty” crusts. Nails are involved in the process. The general condition of the patient suffers (headaches, fever, malaise, bruising), concomitant diseases worsen;
- slit–like impetigo (zaeda) – develops in people sleeping with their mouth open, through the corners of which saliva passively flows out, as well as in those who have a habit of licking their lips. Clinically manifested by a rash of pustules in the corners of the mouth, at the wings of the nose, outside the eye slit. Pustules erode in the form of a slit-like defect of the skin, mucous membranes. The skin around is tense, painful, difficult to epithelize, as lip movements tear thin epithelial films;
- vegetative impetigo – the disease is characterized by the spontaneous spread of opening blisters with the formation of erosions covered with purulent crusts;
- syphil-like impetigo is a disease noted in newborns. A distinctive feature is the rash of flycten on the buttocks and in the subcutaneous area. Flictenes are opened, forming erosions with an infiltrated base, resembling a solid chancre, resolved by the formation of crusts that do not leave a trace;
- intertriginous streptodermia – rashes are localized in large folds of the skin, where, due to aseptic conditions (sweat, wetness), continuous itchy and painful erosive surfaces are formed with a corolla from the remaining epidermis along the periphery. The boundaries of the focus are clear, there is a tendency to peripheral growth;
- mucosal impetigo is a rash of aphth in the oral cavity, on the mucous membrane of the cheeks, gums, tongue, nasal passages, and mucous membranes of the eye.
2. Staphylococcal impetigo (ostiofolliculitis, Bokhart’s impetigo) – occurs in men, children, adolescents. Occurs in the mouths of hair follicles when the rules of elementary cleanliness are not observed. With prolonged existence with no treatment, it transforms into a carbuncle. It exists in two versions:
- bullous form (deep folliculitis) – it is caused by Staphylococcus aureus. It is manifested by the formation of a nodular-vesicular rash (5 mm) around the hair follicles, the primary elements are compacted, tend to penetrate into the deep layers of the skin, the vascular bed, therefore, symptoms of intoxication are present in the clinic, and the outcome of the process is a scar;
- nebulous form (superficial folliculitis) – caused by white staphylococcus, characterized by small (1.5 mm) purulent vesicles, has no tendency to spread, primary elements quickly dry into crusts, which, falling off, do not leave a trace.
3. Mixed impetigo (vulgar impetigo) – occurs when streptococcal impetigo is complicated by staphylococcus, when the appearance of flicten is accompanied by itching, scratching, and the addition of a secondary infection. The rashes are multiple, covered with thick crusts, localized in the face, neck, joints, near the nipples of the breast, on the genitals. Bullae and erosions are painful, tend to spread (through a dirty towel, bed linen), regional lymph nodes are involved in the process.
The clinical picture depends on the type of pathogen. Streptococci cause the appearance of painful, elastic red bubbles up to 5 mm in diameter with serous-purulent contents. Over time, the bubbles become painless, sluggish, open, forming erosions and ulcers, which are resolved by honey-colored scabs. The life cycle of primary elements is up to 2 months. There are no typical localization sites. Children get sick more often due to lack of personal hygiene skills. Streptococcal varieties of impetigo are dangerous due to their complications due to the lympho- and hematogenic spread of infection (tonsillitis, sepsis, scarlet fever, nephritis, rheumatism, myocarditis). A banal complication is considered to be panaritium.
Staphylococcal impetigo is characterized by small pustular rashes around the hair follicles, which explains the typical localization of the process. The severity of possible complications depends on the depth of the skin lesion: skin abscesses, phlegmons, carbuncle. Strepto-staphylococcal skin lesion manifests itself in the form of multiple purulent flickers on the surface of the skin and around the hair follicles, resolved with the formation of massive crusts exposing the erosive surface, with an outcome of slight hyperpigmentation. A distinctive feature of this form of impetigo is the spread of the process with the help of “dropout foci” – new areas of healthy skin capture. Lymph nodes increase, thicken, become painful on palpation. Any impetigo is very contagious.
Diagnosis and treatment
The diagnosis is made by a dermatologist based on anamnesis, clinical manifestations. If there are doubts about the diagnosis, dermatoscopy is performed. Additionally, specific research methods are used: staining of exudate smears by Gram (cocci are visible under a microscope), seeding of the separated bull on flora and an antibioticogram. Self-diagnosis and self-treatment, taking into account the contagiousness of impetigo, are unacceptable. Differentiate impetigo with chickenpox, dermatomycosis, herpes, sycosis, contact and herpetiform dermatitis.
Treatment of uncomplicated forms of impetigo is carried out on an outpatient basis. Therapy has two goals: to eliminate the cause of pathology and improve the general well-being of the patient. Usually, external means are enough to stop the process: the lesion is treated with 2% camphor alcohol, bubbles after opening – fucortsin, ointments with an antibiotic. Vitamin therapy, immunostimulants, sodium deoxyribonucleate are prescribed in the background. All water procedures are prohibited. The course of treatment is 10 days. If the disease continues to spread, antibiotics are connected according to individual schemes: inside or in / m injections. A diet with the absence of sugar-containing products is prescribed, since glucose is a favorable nutrient medium for the spread of microbes. Prevention consists in observing the rules of personal hygiene and the hostel. The prognosis is favorable for life. The recovery is complete.