Bacterial Skin infections

Question 1

What bacteria causes Erysipelas?

Answer 1

strEp pyogenes

Question 2

Describe the appearance of Erysipelas

Answer 2

Raised, red + sharply demarcated border
Superficial; upper dermis + lymphatics
Mainly lower limb unilateral

Question 3

Give 3 features of Erysipelas

Answer 3

Face: butterfly distribution across nose + cheeks
Fever
Orange-peel appearance

Question 4

Ix for Erysipelas + Cellulitis

Answer 4

High WCC, ESR + CRP

Cultures MCS

Question 5

Rx for Erysipelas + Cellulitis

Answer 5

Flucloxacillin (IV if severe)

Clarithromycin (if allergic)

Question 6

What bacteria causes Cellulitis?

Answer 6

Strep pyogenes 2/3

Staph aureus 1/3

Question 7

Describe the skin involvement in celluitis

Answer 7

Lower dermis + SC tissue
Unilateral
Usually limbs

Question 8

How does cellulitis differ from erysipelas?

Answer 8

C: Deeper + less well defined
E: Sharply defined

Question 9

List 3 symptoms at onset of cellulitis

Answer 9

Malaise
Fever
Rigors

Question 10

Describe the skin in cellulitis

Answer 10

Red
Swollen
Painful
Hot

Question 11

Most common causative organism of folliculitis

Answer 11

Staph aureus

Question 12

Describe presentation of folliculitis

Answer 12

Spot, often with white head of pus

Anywhere there are hairs

Question 13

Which organism is associated with spa pool folliculitis?

Answer 13

Pseudomonas aeruginosa

Question 14

Ix for folliculitis

Answer 14

Skin swab for PCR/ gram stain if recurrent/ persistent

Question 15

Tx for folliculitis

Answer 15

Topical Benzoyl peroxide

Question 16

What is Impetigo? What are the 2 sub-types?

Answer 16

Superficial, contagious, blistering infection
Non-bullous (70%)
Bullous

Question 17

Most common causative organism of Impetigo

Answer 17

Staph aureus (NB + B)
Strep progenies (NB)
or both

Question 18

Give 3 characteristics of the skin lesions in Impetigo

Answer 18

Common on face
Red macule- Pustules
Honey-coloured crusted erosions.

Question 19

Ix for Impetigo

Answer 19

Clinical

Skin swab MCS

Question 20

3 Tx options for widespread NB Impetigo

Answer 20

Flucloxacillin PO
Clarithromycin PO (if PenA)
Fusidic acid Topical

Question 21

Tx for limited NB Impetigo

Answer 21

Topical Hydrogen peroxide + skin hygeine

Question 22

Tx for B Impetigo

Answer 22

Flucloxacillin PO
Clarithromycin PO (if PenA)

Question 23

Necrotising fasciitis

Answer 23

Rapidly spreading infection of deep fascia with sub cut tissue necrosis

Question 24

Aetiology of necrotising fasciitis

Answer 24

Group A haemolytic strep
OR
Polymicrobial; aerobe + anaerobe

Question 25

3 Risk factors for necrotising fasciitis

Answer 25

Abdominal surgery
Immunosuppression from chronic illness; DM, cirrhosis
Cutaneous trauma; IVDU, VZV, ulcerative conditions

Question 26

5 features of presentation with necrotising fasciitis

Answer 26

Severe pain/ Anaesthesia
Erythematous, blistering, necrotic skin
Systemically unwell- fever + tachycardia
Crepitus 
Most commonly extremities esp. lower limb

Question 27

Ix for necrotising fasciitis

Answer 27

Surgical exploration

Blood + tissue cultures

Question 28

Tx for necrotising fasciitis

Answer 28

Emergency surgical debridement

Broad spectrum Abx