Bacterial Disease of the Skin
Dr Sami Aldaham
Bacterial infection of the skin
- The surface of the skin has microorganisms, which are most numerous in moist hairy areas rich in sebaceous glands.
- Staphylococcus aureus and group A beta-hemolytic streptococci account for the majority of skin and soft tissue infections.
Presentations
- Cellulitis
- Erysipelas
- Abscess
- Furuncle
- Carbuncle
- Folliculitis
- Impetigo
- Ecthyma
- Sycosis Barbae
- Paronychia
- STAPHYLOCOCCAL SCALDED SKIN SYNDROME (Ritter’s disease)
- Necrotizing fasciitis
Role of Specific Pathogens
- S. aureus invades skin and causes:
- Impetigo, folliculitis, cellulitis, and furuncles.
- Elaboration of toxins by S. aureus causes the lesions of bullous impetigo and staphylococcal scalded skin syndrome.
- Streptococci invade traumatic skin lesions and cause impetigo, erysipelas, cellulitis, and lymphangitis.
Take Home Points
- Cellulitis is a bacterial infection of the dermis that often begins with a portal of entry that is usually a wound, insect bite, or fungal infection (tinea pedis)
- It is important to recognize and treat cellulitis early as untreated cellulitis may lead to sepsis and death
- Erysipelas is a superficial cellulitis with marked dermal lymphatic involvement
- A skin abscess is a loculated infection within the dermis and deeper skin tissues and is best treated with I&D
- Furuncles and carbuncles are a subtype of abscesses, which preferentially occur in skin areas containing hair follicles exposed to friction and perspiration
- Folliculitis is a superficial bacterial infection of the hair follicles presenting as follicular pustules
- In impetigo, papules and vesicles progress to form pustules that enlarge and break down to form thick, adherent crusts with a golden or honey-colored appearance
- Necrotizing fasciitis presents as an expanding dusky, edematous, red plaque with blue discoloration
- Anesthesia of the skin of the affected area is a characteristic finding
- Necrotizing fasciitis is a medical/surgical emergency