Inflammatory diseases of the skin and subcutaneous tissue

Causes and mechanism of development

The absolute majority of local purulent processes are caused by Staphylococcus aureus (Staphylococcus aureus). The pathological process is triggered when microorganisms penetrate the hair follicle. A prerequisite for the onset of the inflammatory response is the disruption of normal outflow of contents from this follicle.

Various systemic factors that weaken the body contribute to the development of the infection. The main predispositions include:

• Pronounced physical exhaustion and vitamin deficiencies.
• Presence of chronic somatic pathologies.
• Metabolic disorders (primarily diabetes mellitus).
• Previous colds and episodes of severe hypothermia.

Topography of lesions

Surgical tactics and diagnosis directly depend on the depth and exact localization of the purulent process in the skin structures. There are five main nosological forms:

1. Furuncle is a purulent-necrotic lesion involving a single hair follicle and the immediately adjacent tissue.
2. Carbuncle is a larger-scale process representing a dense conglomerate of several inflamed hair follicles.
3. Hidradenitis is a specific inflammation affecting the apocrine sweat glands.
4. Erysipelas is a serous-inflammatory disease of the dermis proper, involving the local lymphatic system.
5. Phlegmon is the deepest, most diffuse purulent inflammation spreading in the subcutaneous adipose tissue.

Clinical picture of folliculitis

The typical development of hair follicle inflammation has a clear staging and characteristic local symptoms. The primary element is a small cone-shaped pustule that rises above the skin surface. A hair is always visible in the center of this formation. A narrow rim of hyperemia forms around the pustule, and upon palpation, the surgeon detects a small but distinct infiltrate.

The evolution of the inflammatory element goes through several stages:

1. The inflammation subsides, and a dense purulent crust forms at the site of the pustule.
2. The crust falls off, revealing a small wound. Its surface has a characteristic red, glossy appearance.
3. Epithelialization of the defect occurs, after which a bluish-pink residual spot remains on the skin.

Of particular note is localization on the scalp. In this area, inflammatory nodes often merge with each other. When such massive infiltrates soften, deep purulent tracts form inside them. Healing here is difficult: rough scars remain at the site of the lesions, leading to permanent hair loss in this area (scarring alopecia).

Treatment approaches

Treatment of inflammatory skin diseases requires strict adherence to the hygiene regimen. Patients are strictly prohibited from taking baths and allowing any water to get onto the affected follicles. The hair in the area of inflammation must be cut short to facilitate access to the lesions and reduce the risk of infection spread.

Local treatment:

• The skin strictly around the purulent lesions is treated with a 2% salicylic alcohol solution.
• Mature pustules are carefully opened using a sterile needle.
• The surface of the lesion itself is lubricated with an alcohol solution of iodine or brilliant green—this promotes rapid drying and the formation of a protective crust.

Treatment of chronic forms: In a recurrent course, etiotropic and pathogenetic therapy comes to the fore. A key role is played by the compensation of concomitant pathologies, especially the correction of glucose levels in diabetes mellitus. The regimen is supplemented with systemic antibacterial therapy, vitamin therapy, and immunocorrection methods.

Among physiotherapeutic techniques, high efficacy is demonstrated by:

• Ultraviolet (UV) irradiation of the lesion area.
• Electrophoresis using antibiotics or a specific staphylococcal bacteriophage.
• Diadynamic therapy.

Class and exam questions

What else to study on this topic

• Mechanism of formation of deep purulent tracts on the scalp
• The impact of diabetes mellitus on the chronization of purulent skin processes
• Technique of opening pustules with a sterile needle: indications and safety
• Physiotherapy in purulent surgery: mechanism of action of diadynamic therapy
• Differential diagnosis of erysipelas and phlegmon by depth of lesion

Other topics from the section "CHAPTER 11. SURGICAL INFECTION (PURULENT-INFLAMMATORY DISEASES)"

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.