Acute Purulent Infections: Folliculitis, Furuncle, Carbuncle, Hidradenitis
Overview
Acute purulent infections are pyogenic infections primarily affecting:
- Hair follicles
- Sweat glands
- Sebaceous glands
These infections begin with infiltration, progress to suppuration, and may lead to localized abscess formation or diffuse spread (phlegmon, cellulitis).
Folliculitis
Definition
Folliculitis is an acute inflammation of the hair follicle, which can be:
- Infectious (commonly Staphylococcus aureus )
- Non-infectious (e.g., irritation from shaving)
Clinical Features
- Erythematous papule → pustule formation
- Local redness, pain, swelling
- In severe forms: folliculitis decalvans → alopecia and scarring
From PPT: Corn-stalking appearance, pustules with crusts, especially in beard area = sycosis barbae
Treatmen t
- Extraction of the hair (pilus)
- Local antiseptic solutions
- In recurrent/severe cases: topical or systemic antibiotics
Complications
- May progress to furuncle (boil)
- Potential for scarring if deep
Furuncle (Boil)
Definition
A furuncle is an acute, pyogenic infection of a hair follicle, extending into the sebaceous gland and surrounding subcutaneous tissue.
Etiology
- Most commonly caused by Staphylococcus aureus
Typical Locations
- Neck
- Face
- Axilla
- Gluteal region
Pathogenesis
- Infiltration (inflammatory infiltration)
- Suppuration – central necrosis forms a cavity
- Pus accumulates → surrounded by granulation tissue
Clinical Signs
- Pain, redness, swelling
- Heat and tenderness
- Central fluctuation may be present
- Bluish-red plaque with pustule at center
- Systemic symptoms (fever, malaise) if large
Treatment
- Incision (in "H" or "X" shape per PPT)
- Evacuation of pus
- Installation of antiseptics
- Drainage
- Antibiotics (topical or systemic)
Complications
- Abscess
- Phlegmon
- Lymphangitis
- Recurrence