Impetigo

Question 1

Impetigo is a superficial bacterial skin infection. What is the estimated incidence of impetigo?

1 - 25 / 100,000
2 - 250 / 100,000
3 - 2500 / 100,000
4 - 25,000 / 100,000

Answer 1

2 - 250 / 100,000

Question 2

What age group does the incidence of impetigo peak in?

1 - 1-5
2 - 7-16
3 - 15-25
4 - 30-50

Answer 2

1 - 1-5

Question 3

Which of the following is the hall mark sign of impetigo?

1 - crustation around the nose
2 - erythema of the skin
3 - honey colour crusts on the surface of the skin
4 - deep infection of hair follicles

Answer 3

3 - honey colour crusts on the surface of the skin

Question 4

There are 2 types of impetigo, bullous and non-bullous impetigo. Which of these is more common?

Circumscribed (restricted) elevated lesion containing clear fluid

• vesicle = <0.5cm
• bulla = >0.5cm

Answer 4

• non-bullous

These can appear as vesicles of pustules, commonly referred to as blisters

Question 5

Non-bullous impetigo is the most common form of impetigo and these can initially appear as vesicles or pustules. Does this typically occur on broken or intact skin?

Answer 5

• broken skin

Question 6

Non-bullous impetigo is the most common form of impetigo and these can initially appear as vesicles or pustules. How long before these vesicles or pustules rupture causing the hall mark sign of impetigo honey colour crusts on the surface of the skin?

1 - 12-24h
2 - 1-2 days
3 - 5-7 days
4 - 1-2 weeks

Answer 6

2 - 1-2 days

Once ruptured these are formed on an erythematous moist base

Question 7

Non-bullous impetigo is the most common form of impetigo and these can initially appear as vesicles or pustules. Where are these typically found on the body?

1 - head and feet
2 - hands and feet
3 - face, neck and hands
4 - legs, arms and feet

Answer 7

3 - face, neck and hands

Question 8

Which of the following is the most common cause of non-bullous impetigo?

1 - Group A beta-hemolytic streptococcus/ Streptococcus progenes -PSGN
2 - Staphylococcus aureus
3 - E.coli
4 - pneumococcus

Answer 8

1 - Group A beta-hemolytic streptococcus/ Streptococcus progenes -PSGN

Question 9

Bullous is less common than non-bullous impetigo. Does this typically occur on broken or intact skin?

Answer 9

• intact skin

Appear as bulla

Question 10

Bullous impetigo is typically found on which 2 places of the body?

1 - trunk
2 - face
3 - hands
4 - axilla/groin

Answer 10

1 - trunk
4 - axilla/groin

Question 11

Which of the following is the most common cause of bullous impetigo?

1 - Group A beta-hemolytic streptococcus/ Streptococcus progenes -PSGN
2 - Staphylococcus aureus
3 - E.coli
4 - pneumococcus

Answer 11

2 - Staphylococcus aureus

Question 12

Is impetigo contagious?

Answer 12

• yes, very contagious

Question 13

Impetigo is very contagious, and because it occurs mostly in children aged 1-5, how long should children be kept off school/nursery for once they have started treatment?

1 - 7 days
2 - 5 days
3 - 2 days
4 - 12h

Answer 13

3 - 2 days

• incubation period is typically 4-10 days

Question 14

In addition to the standard signs of bullous and non-bullosu impetigo, such as the bullous and skin blisters, which of the following can patients also experience?

1 - fever like symptoms
2 - lymphadenopathy
3 - pruritus and erythema
4 - all of the above

Answer 14

3 - pruritus and erythema

Question 15

Are topical antibiotics always the 1st line treatment for localised impetigo?

Answer 15

• no
• may start with washing with disinfectants and removing the crust

Question 16

If a patient has impetigo that is localised, what should be the 1st line treatment for patients?

1 - oral antibiotics
2 - emollients
3 - light treatment
4 - topical antibiotics

Answer 16

4 - topical antibiotics

1st choice = Fusidic acid 2%
- 3/5 /day for 5-7 days

2nd choice = Mupirocin
- 3/day for 5-7 days

Question 17

In addition to treating as if the impetigo is only affecting local skin, what treatment should be given if a patient has widespread impetigo with lymphadenopathy, what should be the 1st line treatment for patients?

1 - oral antibiotics
2 - emollients
3 - light treatment
4 - topical antibiotics

Answer 17

1 - oral antibiotics

1st choice = flucloxacillin or clarithromycin
- 5-7 days

BUT still treat in same manner as localised affected skin as well