Bacterial Skin infections Flashcards
What bacteria causes Erysipelas?
strEp pyogenes
Describe the appearance of Erysipelas
Raised, red + sharply demarcated border
Superficial; upper dermis + lymphatics
Mainly lower limb unilateral
Give 3 features of Erysipelas
Face: butterfly distribution across nose + cheeks
Fever
Orange-peel appearance
Ix for Erysipelas + Cellulitis
High WCC, ESR + CRP
Cultures MCS
Rx for Erysipelas + Cellulitis
Flucloxacillin (IV if severe)
Clarithromycin (if allergic)
What bacteria causes Cellulitis?
Strep pyogenes 2/3
Staph aureus 1/3
Describe the skin involvement in celluitis
Lower dermis + SC tissue
Unilateral
Usually limbs
How does cellulitis differ from erysipelas?
C: Deeper + less well defined
E: Sharply defined
List 3 symptoms at onset of cellulitis
Malaise
Fever
Rigors
Describe the skin in cellulitis
Red
Swollen
Painful
Hot
Most common causative organism of folliculitis
Staph aureus
Describe presentation of folliculitis
Spot, often with white head of pus
Anywhere there are hairs
Which organism is associated with spa pool folliculitis?
Pseudomonas aeruginosa
Ix for folliculitis
Skin swab for PCR/ gram stain if recurrent/ persistent
Tx for folliculitis
Topical Benzoyl peroxide
What is Impetigo? What are the 2 sub-types?
Superficial, contagious, blistering infection
Non-bullous (70%)
Bullous
Most common causative organism of Impetigo
Staph aureus (NB + B) Strep progenies (NB) or both
Give 3 characteristics of the skin lesions in Impetigo
Common on face
Red macule- Pustules
Honey-coloured crusted erosions.
Ix for Impetigo
Clinical
Skin swab MCS
3 Tx options for widespread NB Impetigo
Flucloxacillin PO
Clarithromycin PO (if PenA)
Fusidic acid Topical
Tx for limited NB Impetigo
Topical Hydrogen peroxide + skin hygeine
Tx for B Impetigo
Flucloxacillin PO Clarithromycin PO (if PenA)
Necrotising fasciitis
Rapidly spreading infection of deep fascia with sub cut tissue necrosis
Aetiology of necrotising fasciitis
Group A haemolytic strep
OR
Polymicrobial; aerobe + anaerobe
3 Risk factors for necrotising fasciitis
Abdominal surgery
Immunosuppression from chronic illness; DM, cirrhosis
Cutaneous trauma; IVDU, VZV, ulcerative conditions
5 features of presentation with necrotising fasciitis
Severe pain/ Anaesthesia Erythematous, blistering, necrotic skin Systemically unwell- fever + tachycardia Crepitus Most commonly extremities esp. lower limb
Ix for necrotising fasciitis
Surgical exploration
Blood + tissue cultures
Tx for necrotising fasciitis
Emergency surgical debridement
Broad spectrum Abx
