Impetigo

Question 1

What is impetigo?

Answer 1

• = Highly contagious bacterial infection of the epidermis

Question 2

Common organisms causing impetigo

Answer 2

Bacteria that usually live on skin/in throat or nose:
• GABHS (group A beta-haemolytic streptococci)
• Strep pyogenes
• Staph aureus

Question 3

Epidemiology: when most common?

Answer 3

• More common in hotter months and younger children 2-5y

Question 4

Differentiate between the types of impetigo.

Answer 4

○ Non bullous 70% 
	• all ages 
	• Staph aureus & Group A strep 
○ Bullous 30% 
	• Infants & pre-school children
	• Vast majority Staph aureus

Question 5

Why does impetigo usually occur?

Answer 5

• Can happen on healthy skin, but most commonly on already damaged skin e.g. cut, eczema

Question 6

How is impetigo spread? How long is impetigo infectious for?

Answer 6

• Sore is infectious for as long as its weeping, and usually stops ~24h after abx
  • Fluid and crusts contain bacteria
  • Things that have touched sores e.g. dressings
  • Self-spread from itching or seemingly non-affected areas e.g. runny nose

Question 7

What are the key clinical features of impetigo?

Answer 7

• Starts with blisters
  • commonly near mouth, nose, arms, legs
  • Can be small spots around first spot, spreading outwards
  • May be bullous blisters
• Blister bursts, leaving sores
• Sores develop honey-coloured crust +++, itch +++
  +/- fever

Question 8

What Ix should be done for impetigo?

Answer 8

• Skin swab for Gram stain (slide) and culture, test abx susceptibility

Question 9

How to reduce spread of impetigo?

Answer 9

• Daily shower
  ○ Thoroughly wash grazes and cuts
  ○ Remove crusts, even if child taking abx: best way is to bathe for 20-30mins, and wipe crust with wet towel
• Cut nails short - prevent itching
• Cover sores with watertight dressings e.g. Tegaderm
• Throw everything used for the sores away immediately
• Wash affected things separately, and dry in sunshine or in hot dryer. Wash toys in disinfectant.
• Good hygiene - regular hand washing for pt and those in contact
• Don’t return to child care/kinder/school until after 24h treatment started and sores completely covered

Question 10

Tx for impetigo

Answer 10

• Topical mupirocin 2% ointment 8H for uncomplicated, localised sores
• If extensive / multiple lesions present / not responding to topical treatment:treat as for cellulitis (fluclox/cephalexin)