Revision - Cellulitis

Question 1

What are the 3 most common organisms causing cellulitis?

Answer 1

1) Staph. aureus

2) GAS (Strep. pyogenes)

3) GCS (Strep. dysgalactiae)

Question 1

A golden-yellow crust in cellulitis indicates which causative organism?

Answer 1

Staph. aureus

Question 2

What classification system is used to guide management of cellulitis?

Answer 2

Eron classification

Question 3

Describe the Eron classification

Answer 3

Class I - no systemic toxicity or comorbidity

Class II - no systemic toxicity or comorbidity

Class III - significant systemic toxicity or significant comorbidity

Class IV - sepsis or life-threatening infection

Question 4

What Eron classification indicates admission for IV Abx?

Answer 4

Class III & IV

Question 5

What is the most common pathogen causing cellulitis?

Answer 5

Streptococcus:

1) Strep. pyogenes

2) Group A beta-haemolytic streptococci

Question 6

Is a cellulitic rash more likely to be unilateral or bilateral?

Answer 6

Unilateral

Question 7

What should a rapidly progressive and blistering rash prompt consideration of?

Answer 7

Necrotising fasciitis

Question 8

What is cellulitis mx guided by?

Answer 8

Eron classification

Question 9

1st line mx of cellulitis (Eron classification I)?

Answer 9

Oral flucloxacillin

Oral clarithromycin, erythromycin (in pregnancy) or doxycycline is recommended in patients allergic to penicillin.

Question 10

1st line oral abx in pregnancy?

Answer 10

Oral flucloxacillin

Oral erythromycin (if penicillin allergic)

Question 11

What is usually the 1st choice Abx for cellulitis near the eyes or nose?

Answer 11

Co-amoxiclav

Question 12

1st line Abx in severe cellulitis?

Answer 12

Oral/IV co-amoxiclav, oral/IV clindamycin, IV cefuroxime or IV ceftriaxone

Question 13

Lack of what vaccination is a risk factor for orbital cellulitis?

Answer 13

Hib

Question 14

What is necrotising fasciitis?

Answer 14

A severe and rapidly progressive soft tissue infection that causes necrosis of the SC tissues and fascia, sometimes also affecting the muscle.

Question 15

How can NF be categorised?

Answer 15

Categorised depending on the causative organism

Question 16

What are the 4 types of NF?

Answer 16

Type I –> polymicrobial (i.e. multiple anaerobic species)

Type II –> monomicrobial (Strep. pyogenes)

Type III –> monomicrobial (Clostridium species)

Type IV –> fungal (Candida)

Question 17

What is the most common type of NF?

Answer 17

Type I (polymicrobial)

Question 18

What organism causes type II NF?

Answer 18

Strep. pyogenes

Question 19

Who does Type II NF typically occur in?

Answer 19

Younger patients w/ a history of trauma

Question 20

What organism causes type III NF?

Answer 20

Clostridium species

Question 21

Who is type III NF typically found in?

Answer 21

IVDU

Question 22

What organism is type IV NF caused by?

Answer 22

Candida

Question 23

Who is type IV NF typically seen in?

Answer 23

Immunocompromised

Question 24

What is gas gangrene?

Answer 24

Form of NF caused by C. perfringens –> resulting in gas being produced by the bacteria within the tissue.

Question 25

What is the only definitive management of NF?

Answer 25

Surgical debridement

Question 26

What is the site most commonly affected by NF?

Answer 26

Perineum (Fournier’s gangrene)

Question 27

is clarithromycin safe in pregnancy?

Answer 27

No - but erythromycin is

Question 28

1st line abx in pregnancy if patient is penicillin allergic?

Answer 28

Oral erythromycin

Question 29

Diagnosis of cellulitis?

Answer 29

Clinical - no further investigations are required in primary care