Generality
Pyoderma is a skin infection caused by pyogenic bacteria, such as streptococci and staphylococci .
The inflammation that occurs is a variable symptomatic picture, depending mainly on the depth and location of the skin surface involved. However, pyoderma is usually characterized by the appearance of pustules and crusts .
In most cases, pyoderma occurs in areas affected by previous inflammatory dermatoses, traumas, penetrating wounds and rubbing . The establishment of the infection can be facilitated by the reduced barrier function of the skin, which makes it more vulnerable to external aggression.
Pyoderma therapy essentially uses the use of general or local antibiotics .
What's this
Piodermite: what is it?
Pyoderma is a bacterial skin infection . More in detail, the term indicates a set of diseases with variable clinical expression, accumulated by the fact that they are sustained mainly by pyogenic bacteria .
Pyoderma: terminology and synonyms
Pyoderma can affect the skin at the level of the epidermis, dermis and hypodermis ; depending on the depth and the skin structures involved, this infection can be divided into:
- Superficial pyoderma : the infection remains confined to the stratum corneum or, at most, extends to the lumen of the hair follicles. In this form of pyoderma, there is no destruction of the basement membrane;
- Deep pyoderma : the infection succeeds in spreading to the dermis and to the hypodermis. In general, deep pyoderma occurs due to penetrating wounds, depression of the immune system or trauma.
How the skin is made (in short)
- The skin is the largest organ and represents the largest part of the body in contact with the external environment.
- The skin surface is not just a simple shell, but carries out a series of fundamental functions for the organism: it protects from external aggressions (such as traumas), regulates body temperature, promotes the absorption of important substances, etc.
- The skin appears as a thin fabric, covered with hair and small imperfections. In reality, this is composed of three main layers, each of which performs different functions and, in turn, are divided into further zones:
- Epidermis (most superficial layer): it is the external scaffolding of the skin and there are germinative cells, involved in the production of all the skin components. In the epidermis, the stratum corneum is about three-quarters of the epidermis; it is formed from 20 to 30 cellular lamellas, which resemble overlapping "tiles" ("horny scales") which determine the keratinization of the skin and its protection. The cells that form these laminae have no nucleus and have a hard consistency; each of these elements is destined to detach and fall through desquamation, to be replaced by new cells.
- Derma (intermediate part): it is formed by connective tissue, soft and elastic. The dermis is crossed by capillaries, lymphatic vessels and nerve receptors (papillary layer). Furthermore, this portion allows the skin to remain elastic and tight, allowing adequate protection of the whole body (reticular layer);
- Hypoderm or subcutaneous (innermost layer): it connects the dermis and the epidermis to the internal tissues, allowing the anchorage on muscles and bones and favoring the adherence of the skin during the movement of the body.
Depending on the location, it is possible to distinguish different forms of pyoderma, among which the most common are:
- Impetigo ;
- Angular cheilitis ;
- Pyogenic intertrigo ;
- Erysipelas ;
- Boils .
Among these clinical variants, impetigo and angular cheilitis are examples of superficial pyoderma, while erysipelas also affects deep tissues.
Pyoderma occurs with heterogeneous pictures.
These depend on several factors such as:
- Responsible etiological agent;
- Mode of penetration of the infectious agent;
- Virulence of the pathogen;
- Resistance capacity of the organism.
Causes and Risk Factors
Pyoderma: what is it caused by?
Pyoderma is a skin disorder caused by pyogenic germs that infect, in most cases, areas already affected by previous inflammatory dermatoses and skin traumas . These bacteria colonize the skin surface and, under certain conditions that make the skin's defense mechanisms less effective, manage to penetrate the tissues, causing a limited and purulent infection .
The entry point of infectious agents is mainly represented by more exposed areas of the skin (such as face, arms and legs) or subjected to any type of wound, such as a cut, an excoriation or an insect sting.
Pyogenic bacteria: what are they?
The bacteria most commonly responsible for pyoderma are streptococci (such as Streptococcus pyogenes ) and staphylococci (eg Staphylococcus aureus ), either alone or in association with one another. The term "pyogenic" indicates the ability to induce the production of pus .
The skin is vulnerable to aggression by pyogenic bacteria when the mechanisms that normally protect it are lost. The factors that cause this " state of weakness " can be different and include hot-humid environmental conditions, the presence of other diseases, states of immunodepression, the effects of drug therapies, dietary deficiencies and inappropriate personal hygiene.
The transmission of these infectious agents takes place by direct contact, from one person to another, or indirect, through the mixed use of linen, towels and other personal items. Even very frequented wet places (eg swimming pools, gyms, etc.) can predispose to exposure to the bacteria responsible for pyoderma.
Pyoderma: aggravating and predisposing factors
- The proliferation and penetration of the bacteria responsible for pyoderma can be favored by the absence of an adequate skin barrier function . This situation may depend, for example, on a thinner stratum corneum, the loss of the integrity of the skin and alterations of the hydrolipidic film . A greater vulnerability to developing pyoderma may also depend on general immune deficiencies .
- Pyoderma may be the result of other diseases of various kinds. In most cases, the predisposition to infection is found in dermatological diseases of an inflammatory nature, especially those that are allergic or that involve itchy manifestations (note: the itching and scratching that follows can compromise the integrity of the skin surface). If the underlying cause is not dealt with with a definitive therapy, recurrences may occur.
- Pyoderma appears with greater frequency during the summer months, an indication of the fact that bacterial proliferation is favored by hot-humid temperatures .
- Other risk factors, which greatly affect the appearance of pyoderma, are poor hygiene and promiscuity (understood as sharing crowded environments ). Even a high skin pH (> 7) seems to favor the proliferation and penetration of the bacteria responsible for the pathology.
- Pyoderma mainly affects, but is not limited to, children between the ages of two and five.
Symptoms and Complications
Pyoderma: how does it manifest itself?
Depending on the site and the degree of involvement, pyoderma determines symptoms and alterations of varying degrees.
In general, the pyoderma leads to the formation of vesicles, which then become pustules, break and form crusts . At the same time, the skin involved may show redness (erythema), loss of substance (de-epithelialization), flaking and burning.
A typical symptom of pyoderma is also itching : in addition to causing an alteration in skin integrity, yielding to the urge to scratch can predispose to the secondary spread of infection.
In deep forms, there may also be blisters, nodules, ulcers, necrotic areas, fissures and fistulas, sometimes accompanied by enlargement of regional lymph nodes and systemic signs.
Pyoderma: main types
- Intertrigo : it is a superficial pyoderma that develops between closely adjacent skin areas, subjected to a permanent or intermittent contact. The continuous friction and rubbing between the two surfaces causes an increase in temperature and an excess of humidity. Stagnation, sweat and secretions favor skin maceration and colonization by bacteria (mostly Staphylococcus aureus, Streptococcus pyogenes, Proteus spp and Pseudomonas aeruginosa ), yeasts ( Candida ) and dermatophytes. Intertrigo is most evident in overweight people.
- Impetigo : it is a superficial pyoderma that can appear in bullous form (with streptococcal etiology) and non-bullous (caused by staphylococci). The most affected sites are the face and limbs. Itching is a frequent symptom: scratching facilitates the spread of infection to adjacent and non-adjacent skin.
- Boiled impetigo begins with well-defined red patches, on which then blisters and bubbles containing serum and pus are formed. If a person comes into contact with the material contained in these lesions, he in turn contracts the pyoderma. When the bubble breaks, thin crusts form.
- The non-bullous impetigo is characterized by the appearance of groups of vesicles or pustules that break and give rise to thick crusts, surrounded by reddened and inflamed skin. This second form is therefore similar to the bullous impetigo with the difference that the vesicles do not spread rapidly to form bubbles.
- Angular cheilitis : it is a form of superficial pyoderma that affects the corners of the mouth (labial commissures) and involves erythema and cracks.
- Erysipelas : it is a deep pyoderma that can be favored by the presence of other pathologies (eg diabetes and obesity); predominantly affects the face and lower limbs and leads to edema, malaise and abrupt onset fever.
- Folliculitis : they are pyoderma borne by the hair follicle that can act on the surface (ostiofollicoliti) with pustules near the follicles, or in depth (deep folliculitis);
- Boils : they are suppurative pyoderma, usually caused by staphylococcal infections. The boils occur at the level of the follicles and are characterized by the appearance of a nodule with pustule.
Diagnosis
The diagnosis of pyoderma is based on clinical and microbiological evaluation; culture tests can guide treatment.
Pyoderma: which exams are needed?
Generally, a doctor's visit is sufficient to establish the presence of pyoderma. Performing a culture test isolates the microorganism responsible for the infection and helps define the therapeutic process.
Treatment and Remedies
The treatment of pyoderma includes the use of:
- Antiseptics : topical compresses with disinfectant substances (such as, for example, chlorhexidine gluconate or iodopovidone) are useful for cleaning the infected area and removing scabs;
- Topical antibiotics : the choice of the drug is subject to the cause that caused the pyoderma; in general, antibiotic therapy may include erythromycin, gentamicin or bacitracin. The administration of antibiotics must last at least 10-15 days; after this period the doctor will have to evaluate the response to the therapy.
The forms of pyoderma particularly widespread and resistant to topical treatment should be treated with systemic antibiotics .
In addition to appropriate therapies, personal hygiene care plays a fundamental role in the management of infection. In particular, it is necessary to frequently wash the hands, the laundry and, in general, the objects that have come into contact with the person suffering from pyoderma.
