Staphylococcal skin infections is a group of pyoderma of bacterial etiology caused by microorganisms from the staphylococcus group. The symptoms of this condition and their severity vary depending on the form of the skin lesion, the type of reactivity of the body, the presence of concomitant disorders (decreased activity of immunity, skin damage). Diagnosis of various forms is carried out on the basis of the results of dermatological examination, microbiological studies of the skin and pus. General clinical blood and urine tests can play an auxiliary role. Treatment is performed by a variety of local and systemic antibacterial agents, supportive medications, physiotherapy.
Staphylococcal skin infections (staphylococcal pyoderma) is a set of purulent-inflammatory skin lesions caused by staphylococci. It is a very widespread dermatological condition – almost every person has purulent skin inflammations of varying severity caused by these bacteria during their lifetime. Such a frequent occurrence is due to the fact that staphylococci are quite widely represented in the environment – they can stay in the air and on household items for a long time, be part of the microflora of the skin and mucous membranes of a person. In addition, staphylococcal skin infections is sometimes provoked by the introduction of pathogenic bacteria from other purulent foci in the body. The lesion can occur at any age, but in children staphylococcal skin infections proceeds differently than in adults (epidemic pemphigus of newborns) due to certain anatomical features of the structure of the skin. Due to the bacterial nature of the disease and the resistance of staphylococci in the external environment, such conditions have a pronounced contagiousness, can be transmitted by touching or through common objects (towels, bed linen, washcloths), which must be taken into account when treating pathology.
The cause of the development of all forms is the penetration of staphylococci (usually golden or white) into the skin tissue through microcracks, ducts of sebaceous and sweat glands or open wounds (abrasions and cuts). Less often, hematogenic or lymphogenic metastatic drift of the pathogen from other foci of purulent infection (carious teeth, abscesses of internal organs, lymphadenitis) is observed. At the same time, the form of staphylococcal skin infections depends on the depth of penetration of staphylococci, their activity (especially in terms of the release of proteolytic enzymes and exotoxins) and the type of reactivity of the body.
After bacteria enter the skin tissues in the absence of local factors of immunological protection, rapid reproduction of microorganisms begins with the release of a huge number of enzymes and immunogenic toxins. This characterizes the first stage of the development of any purulent process, including staphylococcal skin infections. Then, immunocompetent cells (neutrophils, macrophages, lymphocytes) begin to migrate to the lesion, which stimulate inflammation through the release of biologically active substances. There is an expansion of blood vessels, swelling of tissues, the formation of an “inflammatory shaft” around the focus of bacteria – these processes constitute the clinical picture of staphylococcal skin infections. At subsequent stages of development, fibroblasts are activated, forming a capsule around the pathological focus, and a mixture of dead neutrophils and staphylococci together with decayed tissues forms pus.
If the purulent inflammation is extensive, a significant amount of toxins penetrates into the blood, which leads to the development of common symptoms – weakness, fever, headache. In most cases of staphylococcal skin infections, sooner or later, drainage is naturally formed for the outflow of pus (abscess breakthrough), inflammatory manifestations gradually fade away. If the pathological process has affected the basement membrane of the epidermis, a more or less noticeable scar is formed on the site of the pathological focus. With superficial forms of staphylococcal skin infections, the basement membrane remains intact, which contributes to complete healing and restoration of normal skin.
Classification and symptoms
Different forms of staphylococcal skin infections have quite a lot of differences in their clinical course, which allows a dermatologist to determine its type by the symptoms of the disease alone. It is on these differences that the classification of this purulent-inflammatory condition is based. Staphylococcal skin infections can be superficial, deep and infantile. Surface forms include various types of folliculitis (ostiofolliculitis, superficial and deep folliculitis), as well as vulgar sycosis. Deep types combine boils, carbuncles and staphylococcal hydradenitis. The children’s form of this skin lesion is represented by epidemic pemphigus of newborns, which pathomorphologically belongs to the surface types, but has a number of features due to the structure of the skin of young children.
Ostiofolliculitis (Bockhart’s staphylococcal impetigo) is a fairly mild type of superficial staphylococcal skin infections. Most often it affects men, occurs on the face in the growth zone of the mustache and beard, always affects the area around the hair shaft, can have multiple or single character. The beginning of the pathological process is characterized by the appearance of a red pustule with a diameter of about 1 millimeter, in place of which a hemispherical yellowish abscess forms over time. After 2-3 days, it transforms into a dirty yellow crust with a diameter of 2-3 millimeters. After another 2-3 days, the crust disappears, a pink spot may remain in its place for about a week, which then completely disappears.
Superficial folliculitis can be conditionally called a complicated form of the previous variant, since it is characterized by a deeper lesion of the hair follicles. The clinical picture resembles ostiofolliculitis, but it is more pronounced – the size of papular elements reaches 2-3 millimeters in diameter, and complete healing can take up to 2-3 weeks. Around the lesions, as a rule, there is an inflammatory roller and redness of the skin, local soreness is often noted, but there are no general symptoms (weakness, fever) with superficial folliculitis.
Deep folliculitis is a pronounced form of superficial staphylococcal skin infections, in which the purulent-inflammatory process covers the entire thickness of the hair follicle. It is manifested by single or multiple pustules with a diameter of up to 10-15 millimeters of various localization. In some cases, there is a significant area of skin damage caused by multiple folliculitis, which may indicate the presence of immunodeficiency, diabetes mellitus and other common diseases. In this variant of staphylococcal skin infections, moderate skin soreness is noted, with extensive lesions, general symptoms may be registered: weakness, headache, fever.
Vulgar sycosis is a chronic type of staphylococcal skin infections, most often having a recurrent course. Mainly affects men, occurs on the face and neck, sometimes in the pubic area or on the back. There are several stages in the development of vulgar sycosis. Initially, single superficial folliculitis forms on the skin, spontaneously disappearing after a few days. After that, deeper purulent disc-shaped lesions appear, which merge with each other, forming extensive greenish-yellow crusts. When they are separated, painful erosive surfaces with a long healing period are determined on the skin.
Furuncle is a variant of deep staphylococcal skin infections, a feature of which is the purulent-necrotic nature of inflammation. Most often it forms on the face, neck, shoulders, sometimes boils may appear on the back and buttocks. The duration of development of this form of staphylococcal skin infections is about 14 days, the process includes three stages. First, there is a pronounced inflammatory infiltration, accompanied by redness, soreness, and compaction of the skin in the affected area. Then the formation of an abscess with a necrotic rod in the middle begins, the size of the abscess can reach 5 centimeters, there is an increase in body temperature and a deterioration in the general condition of the body. The third stage of this form of staphylococcal skin infections (healing) is characterized by the development of granulation and scarring. In some cases, there may be multiple formation of boils, which is called furunculosis – usually this process is detected with a general weakening of the body.
Carbuncle is a type of staphylococcal skin infections that resembles a boil, but differs from it by the defeat of several closely located follicles at once with the involvement of an extensive volume of skin tissues. The process is characterized by more pronounced symptoms – infiltration can reach a diameter of 10-20 centimeters, the size of the ulcers is 2-6 centimeters. After the formation of an inflammatory focus and abscess, it softens with the release of a large amount of pus and several necrotic rods. This form is always accompanied by a significant deterioration in the general condition (fever, chills) and regional lymphadenitis.
Epidemic pemphigus of newborns is a form that affects only children in the first weeks of their life. It may be a consequence of the introduction of staphylococci from the mother’s genital tract, nosocomial infection, sometimes primary immunodeficiency. A symptom of the pemphigus of newborns is the development of numerous papules with transparent contents on the body. Often papules merge with each other and can capture almost the entire surface of the child’s body. After the destruction of the papules, a strongly eroded surface of the skin remains.
In dermatology, methods of dermatological examination and bacteriological examination of pus are used to determine staphylococcal skin infections, a general blood test plays an auxiliary role. Upon examination, the doctor can determine the depth and nature of the purulent-inflammatory lesion, as well as its stage, on the basis of which he decides on the nature of further treatment. The bacteriological study is based on the sowing of purulent discharge and further identification of the pathogen – first of all, this is necessary to exclude streptococcal pyoderma. Also, within the framework of this study, the sensitivity of the causative agent of staphylococcal skin infections to antibiotics for further therapy can be determined. General tests can characterize the severity of the inflammatory process – neutrophilic leukocytosis is detected in the blood, a sharp increase in the rate of erythrocyte sedimentation.
Treatment of most forms of superficial staphylococcal skin infections, as a rule, is local, based on the use of ointments with antibiotics, antiseptics and other antimicrobial agents. In chronic types of the disease, such as vulgar sycosis, ultraviolet irradiation and other physiotherapy techniques are also used. With deep forms of staphylococcal skin infections, systemic antibiotics from the group of macrolides or tetracyclines are almost always prescribed – this is done not only for the speedy recovery of the patient, but also for the prevention of complications (metastatic spread of infection or sepsis). In cases where staphylococcal skin infections is caused by common diseases (immunodeficiency, diabetes mellitus), their therapy also contributes to a speedy recovery.
Prognosis and prevention
The prognosis of staphylococcal skin infections, especially its superficial forms, is most often favorable – after the resolution of the purulent-inflammatory focus, no traces remain on the skin. With deep forms of the disease, the formation of granulations, more or less noticeable scars and long-existing infiltrates is possible. Potentially, any type of staphylococcal skin infections can lead to severe complications, such as sepsis, purulent lymphadenitis, abscesses of internal organs, which poses a threat to human life. Extremely rarely, with extensive lesions, a toxic shock occurs due to the waste products of staphylococci and tissue decay. Only timely antibacterial therapy will help to avoid such manifestations. To prevent staphylococcal skin infections, it is necessary to maintain immunity at the proper level, keep the skin clean, treat skin damage with antiseptics, avoid using other people’s razors, towels, washcloths.